Correct Generating-stubs.md example JSON (#76)

I believe the example JSON is missing a comma so I inserted it; then
fixed up other JSON issues.

.github/workflows/main.yml

@@ -13,9 +13,10 @@ jobs:
     with:
       linux_5_9_enabled: false
       linux_5_10_enabled: false
-      linux_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -warnings-as-errors -Xswiftc -require-explicit-availability"
-      linux_nightly_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_6_1_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -warnings-as-errors -Xswiftc -require-explicit-availability"
-      linux_nightly_main_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_nightly_next_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-availability"
+      linux_nightly_main_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-availability"
 
   construct-plugin-tests-matrix:
     name: Construct plugin tests matrix
@@ -32,7 +33,7 @@ jobs:
         env:
           MATRIX_LINUX_5_9_ENABLED: false
           MATRIX_LINUX_5_10_ENABLED: false
-          MATRIX_LINUX_COMMAND: "curl -s https://raw.githubusercontent.com/rnro/grpc-swift-protobuf/refs/heads/build_plugin_integration_tests/dev/plugin-tests.sh | GITHUB_ACTIONS=true bash"
+          MATRIX_LINUX_COMMAND: "./dev/plugin-tests.sh"
           MATRIX_LINUX_SETUP_COMMAND: "apt-get update -y -q && apt-get install -y -q curl protobuf-compiler"
 
   plugin-tests-matrix:
@@ -42,3 +43,7 @@ jobs:
     with:
       name: "Plugin tests"
       matrix_string: '${{ needs.construct-plugin-tests-matrix.outputs.plugin-tests-matrix }}'
+
+  static-sdk:
+    name: Static SDK
+    uses: apple/swift-nio/.github/workflows/static_sdk.yml@main

.github/workflows/pull_request.yml

@@ -11,6 +11,9 @@ jobs:
     uses: swiftlang/github-workflows/.github/workflows/soundness.yml@main
     with:
       license_header_check_project_name: "gRPC"
+      # This is done by a similar job defined in soundness.yml. It needs to be
+      # separate in order to export an environment variable.
+      api_breakage_check_enabled: false
 
   grpc-soundness:
     name: Soundness
@@ -22,9 +25,10 @@ jobs:
     with:
       linux_5_9_enabled: false
       linux_5_10_enabled: false
-      linux_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -warnings-as-errors -Xswiftc -require-explicit-availability"
-      linux_nightly_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_6_1_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -warnings-as-errors -Xswiftc -require-explicit-availability"
-      linux_nightly_main_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_nightly_next_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-availability"
+      linux_nightly_main_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-availability"
 
   construct-plugin-tests-matrix:
     name: Construct plugin tests matrix
@@ -41,7 +45,7 @@ jobs:
         env:
           MATRIX_LINUX_5_9_ENABLED: false
           MATRIX_LINUX_5_10_ENABLED: false
-          MATRIX_LINUX_COMMAND: "curl -s https://raw.githubusercontent.com/rnro/grpc-swift-protobuf/refs/heads/build_plugin_integration_tests/dev/plugin-tests.sh | GITHUB_ACTIONS=true bash"
+          MATRIX_LINUX_COMMAND: "./dev/plugin-tests.sh"
           MATRIX_LINUX_SETUP_COMMAND: "apt-get update -y -q && apt-get install -y -q curl protobuf-compiler"
 
   plugin-tests-matrix:
@@ -58,3 +62,7 @@ jobs:
     with:
       linux_5_9_enabled: false
       linux_5_10_enabled: false
+
+  static-sdk:
+    name: Static SDK
+    uses: apple/swift-nio/.github/workflows/static_sdk.yml@main

.github/workflows/soundness.yml

@@ -35,3 +35,28 @@ jobs:
       - name: Check generated code
         run: |
           ./dev/check-generated-code.sh
+
+  api-breakage-check:
+    name: API breakage check
+    runs-on: ubuntu-latest
+    container:
+      image: swift:latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+          fetch-depth: 0  # Fetching tags requires fetch-depth: 0 (https://github.com/actions/checkout/issues/1471)
+      - name: Mark the workspace as safe
+        # https://github.com/actions/checkout/issues/766
+        run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
+      - name: Run API breakage check
+        shell: bash
+        # See package.swift for why we set GRPC_SWIFT_PROTOBUF_NO_VERSION=1
+        run: |
+          export GRPC_SWIFT_PROTOBUF_NO_VERSION=1
+
+          git fetch ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} ${GITHUB_BASE_REF}:pull-base-ref
+          BASELINE_REF='pull-base-ref'
+          echo "Using baseline: $BASELINE_REF"
+          swift package diagnose-api-breaking-changes "$BASELINE_REF"

IntegrationTests/PluginTests/Resources/Protos/noop/noop.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+import "google/protobuf/empty.proto";
+
+package noop;
+
+service NoOpService {
+  rpc NoOp(google.protobuf.Empty) returns (google.protobuf.Empty);
+}

IntegrationTests/PluginTests/Resources/Protos/noop2/noop.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+import "google/protobuf/empty.proto";
+
+package noop2;
+
+service NoOpService {
+  rpc NoOp(google.protobuf.Empty) returns (google.protobuf.Empty);
+}

IntegrationTests/PluginTests/Resources/Sources/NoOp.swift

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2025, gRPC Authors All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import GRPCCore
+import GRPCProtobuf
+import SwiftProtobuf
+
+@main
+struct PluginAdopter {
+  static func main() async throws {
+  }
+}
+
+struct NoOp: Noop_NoOpService.SimpleServiceProtocol {
+  func noOp(
+    request: Google_Protobuf_Empty,
+    context: ServerContext
+  ) async throws -> Google_Protobuf_Empty {
+    return Google_Protobuf_Empty()
+  }
+}
+
+struct NoOp2: Noop2_NoOpService.SimpleServiceProtocol {
+  func noOp(
+    request: Google_Protobuf_Empty,
+    context: ServerContext
+  ) async throws -> Google_Protobuf_Empty {
+    return Google_Protobuf_Empty()
+  }
+}

IntegrationTests/PluginTests/Resources/Sources/Package.swift

@@ -28,18 +28,17 @@ let package = Package(
   ],
   dependencies: [
     // Dependency on grpc-swift-protobuf to be added by setup-plugin-tests.sh script
-
     .package(
-      url: "https://github.com/grpc/grpc-swift.git",
+      url: "https://github.com/grpc/grpc-swift-2.git",
-      exact: "2.0.0-rc.1"
+      from: "2.0.0"
     )
   ],
   targets: [
     .executableTarget(
       name: "grpc-adopter",
       dependencies: [
-        .product(name: "GRPCCore", package: "grpc-swift"),
+        .product(name: "GRPCCore", package: "grpc-swift-2"),
-        .product(name: "GRPCInProcessTransport", package: "grpc-swift"),
+        .product(name: "GRPCInProcessTransport", package: "grpc-swift-2"),
         .product(name: "GRPCProtobuf", package: "grpc-swift-protobuf"),
       ],
       plugins: [

Package.swift

@@ -23,19 +23,23 @@ let products: [Product] = [
     targets: ["GRPCProtobuf"]
   ),
   .executable(
-    name: "protoc-gen-grpc-swift",
+    name: "protoc-gen-grpc-swift-2",
-    targets: ["protoc-gen-grpc-swift"]
+    targets: ["protoc-gen-grpc-swift-2"]
   ),
   .plugin(
     name: "GRPCProtobufGenerator",
     targets: ["GRPCProtobufGenerator"]
   ),
+  .plugin(
+    name: "generate-grpc-code-from-protos",
+    targets: ["generate-grpc-code-from-protos"]
+  ),
 ]
 
 let dependencies: [Package.Dependency] = [
   .package(
-    url: "https://github.com/grpc/grpc-swift.git",
+    url: "https://github.com/grpc/grpc-swift-2.git",
-    exact: "2.0.0-rc.1"
+    from: "2.0.0"
   ),
   .package(
     url: "https://github.com/apple/swift-protobuf.git",
@@ -43,20 +47,36 @@ let dependencies: [Package.Dependency] = [
   ),
 ]
 
-let defaultSwiftSettings: [SwiftSetting] = [
+// -------------------------------------------------------------------------------------------------
-  .swiftLanguageMode(.v6),
-  .enableUpcomingFeature("ExistentialAny"),
-  .enableUpcomingFeature("InternalImportsByDefault"),
-  .enableUpcomingFeature("MemberImportVisibility"),
-]
 
-let targets: [Target] = [
+// This adds some build settings which allow us to map "@available(gRPCSwiftProtobuf 2.x, *)" to
-  // protoc plugin for grpc-swift
+// the appropriate OS platforms.
+let nextMinorVersion = 1
+let availabilitySettings: [SwiftSetting] = (0 ... nextMinorVersion).map { minor in
+  let name = "gRPCSwiftProtobuf"
+  let version = "2.\(minor)"
+  let platforms = "macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0"
+  let setting = "AvailabilityMacro=\(name) \(version):\(platforms)"
+  return .enableExperimentalFeature(setting)
+}
+
+let defaultSwiftSettings: [SwiftSetting] =
+  availabilitySettings + [
+    .swiftLanguageMode(.v6),
+    .enableUpcomingFeature("ExistentialAny"),
+    .enableUpcomingFeature("InternalImportsByDefault"),
+    .enableUpcomingFeature("MemberImportVisibility"),
+  ]
+
+// -------------------------------------------------------------------------------------------------
+
+var targets: [Target] = [
+  // protoc plugin for grpc-swift-2
   .executableTarget(
-    name: "protoc-gen-grpc-swift",
+    name: "protoc-gen-grpc-swift-2",
     dependencies: [
       .target(name: "GRPCProtobufCodeGen"),
-      .product(name: "GRPCCodeGen", package: "grpc-swift"),
+      .product(name: "GRPCCodeGen", package: "grpc-swift-2"),
       .product(name: "SwiftProtobuf", package: "swift-protobuf"),
       .product(name: "SwiftProtobufPluginLibrary", package: "swift-protobuf"),
     ],
@@ -67,7 +87,7 @@ let targets: [Target] = [
   .target(
     name: "GRPCProtobuf",
     dependencies: [
-      .product(name: "GRPCCore", package: "grpc-swift"),
+      .product(name: "GRPCCore", package: "grpc-swift-2"),
       .product(name: "SwiftProtobuf", package: "swift-protobuf"),
     ],
     swiftSettings: defaultSwiftSettings
@@ -76,18 +96,18 @@ let targets: [Target] = [
     name: "GRPCProtobufTests",
     dependencies: [
       .target(name: "GRPCProtobuf"),
-      .product(name: "GRPCCore", package: "grpc-swift"),
+      .product(name: "GRPCCore", package: "grpc-swift-2"),
-      .product(name: "GRPCInProcessTransport", package: "grpc-swift"),
+      .product(name: "GRPCInProcessTransport", package: "grpc-swift-2"),
       .product(name: "SwiftProtobuf", package: "swift-protobuf"),
     ],
     swiftSettings: defaultSwiftSettings
   ),
 
-  // Code generator library for protoc-gen-grpc-swift
+  // Code generator library for protoc-gen-grpc-swift-2
   .target(
     name: "GRPCProtobufCodeGen",
     dependencies: [
-      .product(name: "GRPCCodeGen", package: "grpc-swift"),
+      .product(name: "GRPCCodeGen", package: "grpc-swift-2"),
       .product(name: "SwiftProtobufPluginLibrary", package: "swift-protobuf"),
     ],
     swiftSettings: defaultSwiftSettings
@@ -96,7 +116,7 @@ let targets: [Target] = [
     name: "GRPCProtobufCodeGenTests",
     dependencies: [
       .target(name: "GRPCProtobufCodeGen"),
-      .product(name: "GRPCCodeGen", package: "grpc-swift"),
+      .product(name: "GRPCCodeGen", package: "grpc-swift-2"),
       .product(name: "SwiftProtobuf", package: "swift-protobuf"),
       .product(name: "SwiftProtobufPluginLibrary", package: "swift-protobuf"),
     ],
@@ -111,21 +131,81 @@ let targets: [Target] = [
     name: "GRPCProtobufGenerator",
     capability: .buildTool(),
     dependencies: [
-      .target(name: "protoc-gen-grpc-swift"),
+      .target(name: "protoc-gen-grpc-swift-2"),
       .product(name: "protoc-gen-swift", package: "swift-protobuf"),
     ]
   ),
+
+  // Code generator SwiftPM command
+  .plugin(
+    name: "generate-grpc-code-from-protos",
+    capability: .command(
+      intent: .custom(
+        verb: "generate-grpc-code-from-protos",
+        description: "Generate Swift code for gRPC services from protobuf definitions."
+      ),
+      permissions: [
+        .writeToPackageDirectory(
+          reason:
+            "To write the generated Swift files back into the source directory of the package."
+        )
+      ]
+    ),
+    dependencies: [
+      .target(name: "protoc-gen-grpc-swift-2"),
+      .product(name: "protoc-gen-swift", package: "swift-protobuf"),
+    ],
+    path: "Plugins/GRPCProtobufGeneratorCommand"
+  ),
 ]
 
+// -------------------------------------------------------------------------------------------------
+
+extension Context {
+  fileprivate static var versionString: String {
+    guard let git = Self.gitInformation else { return "" }
+
+    if let tag = git.currentTag {
+      return tag
+    } else {
+      let suffix = git.hasUncommittedChanges ? " (modified)" : ""
+      return git.currentCommit + suffix
+    }
+  }
+
+  fileprivate static var buildCGRPCProtobuf: Bool {
+    let noVersion = Context.environment.keys.contains("GRPC_SWIFT_PROTOBUF_NO_VERSION")
+    return !noVersion
+  }
+}
+
+// Having a C module as a transitive dependency of a plugin seems to trip up the API breakage
+// checking tool. See also https://github.com/swiftlang/swift-package-manager/issues/8081
+//
+// The CGRPCProtobuf module (which only includes package version information) is conditionally
+// compiled and included based on an environment variable. This is set in CI only for the API
+// breakage checking job to avoid tripping up SwiftPM.
+if Context.buildCGRPCProtobuf {
+  targets.append(
+    .target(
+      name: "CGRPCProtobuf",
+      cSettings: [
+        .define("CGRPC_GRPC_SWIFT_PROTOBUF_VERSION", to: "\"\(Context.versionString)\"")
+      ]
+    )
+  )
+
+  for target in targets {
+    if target.name == "protoc-gen-grpc-swift-2" {
+      target.dependencies.append(.target(name: "CGRPCProtobuf"))
+    }
+  }
+}
+
+// -------------------------------------------------------------------------------------------------
+
 let package = Package(
   name: "grpc-swift-protobuf",
-  platforms: [
-    .macOS(.v15),
-    .iOS(.v18),
-    .tvOS(.v18),
-    .watchOS(.v11),
-    .visionOS(.v2),
-  ],
   products: products,
   dependencies: dependencies,
   targets: targets

Plugins/GRPCProtobufGenerator/BuildPluginConfig.swift

@@ -16,8 +16,6 @@
 
 import Foundation
 
-let configFileName = "grpc-swift-proto-generator-config.json"
-
 /// The config of the build plugin.
 struct BuildPluginConfig: Codable {
   /// Config defining which components should be considered when generating source.
@@ -193,12 +191,14 @@ extension BuildPluginConfig.Protoc: Codable {
 
 extension GenerationConfig {
   init(buildPluginConfig: BuildPluginConfig, configFilePath: URL, outputPath: URL) {
-    self.server = buildPluginConfig.generate.servers
+    self.servers = buildPluginConfig.generate.servers
-    self.client = buildPluginConfig.generate.clients
+    self.clients = buildPluginConfig.generate.clients
-    self.message = buildPluginConfig.generate.messages
+    self.messages = buildPluginConfig.generate.messages
-    // hard-code full-path to avoid collisions since this goes into a temporary directory anyway
+    // Use path to underscores as it ensures output files are unique (files generated from
-    self.fileNaming = .fullPath
+    // "foo/bar.proto" won't collide with those generated from "bar/bar.proto" as they'll be
-    self.visibility = buildPluginConfig.generatedSource.accessLevel
+    // uniquely named "foo_bar.(grpc|pb).swift" and "bar_bar.(grpc|pb).swift".
+    self.fileNaming = .pathToUnderscores
+    self.accessLevel = buildPluginConfig.generatedSource.accessLevel
     self.accessLevelOnImports = buildPluginConfig.generatedSource.accessLevelOnImports
     // Generate absolute paths for the imports relative to the config file in which they are specified
     self.importPaths = buildPluginConfig.protoc.importPaths.map { relativePath in

Plugins/GRPCProtobufGenerator/BuildPluginError.swift

@@ -1,5 +1,5 @@
 /*
- * Copyright 2024, gRPC Authors All rights reserved.
+ * Copyright 2025, gRPC Authors All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,13 +14,12 @@
  * limitations under the License.
  */
 
-enum PluginError: Error {
+enum BuildPluginError: Error {
-  // Build plugin
   case incompatibleTarget(String)
   case noConfigFilesFound
 }
 
-extension PluginError: CustomStringConvertible {
+extension BuildPluginError: CustomStringConvertible {
   var description: String {
     switch self {
     case .incompatibleTarget(let target):

Plugins/GRPCProtobufGenerator/Plugin.swift

@@ -19,10 +19,9 @@ import PackagePlugin
 
 // Entry-point when using Package manifest
 extension GRPCProtobufGenerator: BuildToolPlugin {
-  /// Create build commands, the entry-point when using a Package manifest.
   func createBuildCommands(context: PluginContext, target: Target) async throws -> [Command] {
     guard let swiftTarget = target as? SwiftSourceModuleTarget else {
-      throw PluginError.incompatibleTarget(target.name)
+      throw BuildPluginError.incompatibleTarget(target.name)
     }
     let configFiles = swiftTarget.sourceFiles(withSuffix: configFileName).map { $0.url }
     let inputFiles = swiftTarget.sourceFiles(withSuffix: ".proto").map { $0.url }
@@ -41,7 +40,6 @@ import XcodeProjectPlugin
 
 // Entry-point when using Xcode projects
 extension GRPCProtobufGenerator: XcodeBuildToolPlugin {
-  /// Create build commands, the entry-point when using an Xcode project.
   func createBuildCommands(context: XcodePluginContext, target: XcodeTarget) throws -> [Command] {
     let configFiles = target.inputFiles.filter {
       $0.url.lastPathComponent == configFileName
@@ -62,7 +60,7 @@ extension GRPCProtobufGenerator: XcodeBuildToolPlugin {
 
 @main
 struct GRPCProtobufGenerator {
-  /// Build plugin code common to both invocation types: package manifest Xcode project
+  /// Build plugin common code
   func createBuildCommands(
     pluginWorkDirectory: URL,
     tool: (String) throws -> PluginContext.Tool,
@@ -72,13 +70,13 @@ struct GRPCProtobufGenerator {
   ) throws -> [Command] {
     let configs = try readConfigFiles(configFiles, pluginWorkDirectory: pluginWorkDirectory)
 
-    let protocGenGRPCSwiftPath = try tool("protoc-gen-grpc-swift").url
+    let protocGenGRPCSwiftPath = try tool("protoc-gen-grpc-swift-2").url
     let protocGenSwiftPath = try tool("protoc-gen-swift").url
 
     var commands: [Command] = []
     for inputFile in inputFiles {
       guard let (configFilePath, config) = configs.findApplicableConfig(for: inputFile) else {
-        throw PluginError.noConfigFilesFound
+        throw BuildPluginError.noConfigFilesFound
       }
 
       let protocPath = try deriveProtocPath(using: config, tool: tool)
@@ -90,7 +88,7 @@ struct GRPCProtobufGenerator {
       }
 
       // unless *explicitly* opted-out
-      if config.client || config.server {
+      if config.clients || config.servers {
         let grpcCommand = try protocGenGRPCSwiftCommand(
           inputFile: inputFile,
           config: config,
@@ -104,7 +102,7 @@ struct GRPCProtobufGenerator {
       }
 
       // unless *explicitly* opted-out
-      if config.message {
+      if config.messages {
         let protoCommand = try protocGenSwiftCommand(
           inputFile: inputFile,
           config: config,
@@ -167,16 +165,16 @@ extension [URL: GenerationConfig] {
   }
 }
 
-/// Construct the command to invoke `protoc` with the `protoc-gen-grpc-swift` plugin.
+/// Construct the command to invoke `protoc` with the `protoc-gen-grpc-swift-2` plugin.
 /// - Parameters:
 ///   - inputFile: The input `.proto` file.
 ///   - config: The config for this operation.
 ///   - baseDirectoryPath: The root path to the source `.proto` files used as the reference for relative path naming schemes.
 ///   - protoDirectoryPaths: The paths passed to `protoc` in which to look for imported proto files.
 ///   - protocPath: The path to `protoc`
-///   - protocGenGRPCSwiftPath: The path to `protoc-gen-grpc-swift`.
+///   - protocGenGRPCSwiftPath: The path to `protoc-gen-grpc-swift-2`.
 ///   - configFilePath: The path to the config file in use.
-/// - Returns: The command to invoke `protoc` with the `protoc-gen-grpc-swift` plugin.
+/// - Returns: The command to invoke `protoc` with the `protoc-gen-grpc-swift-2` plugin.
 func protocGenGRPCSwiftCommand(
   inputFile: URL,
   config: GenerationConfig,
@@ -189,7 +187,7 @@ func protocGenGRPCSwiftCommand(
   let outputPathURL = URL(fileURLWithPath: config.outputPath)
 
   let outputFilePath = deriveOutputFilePath(
-    for: inputFile,
+    protoFile: inputFile,
     baseDirectoryPath: baseDirectoryPath,
     outputDirectory: outputPathURL,
     outputExtension: "grpc.swift"
@@ -224,7 +222,7 @@ func protocGenGRPCSwiftCommand(
 ///   - baseDirectoryPath: The root path to the source `.proto` files used as the reference for relative path naming schemes.
 ///   - protoDirectoryPaths: The paths passed to `protoc` in which to look for imported proto files.
 ///   - protocPath: The path to `protoc`
-///   - protocGenSwiftPath: The path to `protoc-gen-grpc-swift`.
+///   - protocGenSwiftPath: The path to `protoc-gen-grpc-swift-2`.
 ///   - configFilePath: The path to the config file in use.
 /// - Returns: The command to invoke `protoc` with the `protoc-gen-swift` plugin.
 func protocGenSwiftCommand(
@@ -239,7 +237,7 @@ func protocGenSwiftCommand(
   let outputPathURL = URL(fileURLWithPath: config.outputPath)
 
   let outputFilePath = deriveOutputFilePath(
-    for: inputFile,
+    protoFile: inputFile,
     baseDirectoryPath: baseDirectoryPath,
     outputDirectory: outputPathURL,
     outputExtension: "pb.swift"
@@ -267,28 +265,32 @@ func protocGenSwiftCommand(
   )
 }
 
-/// Derive the expected output file path to match the behavior of the `protoc-gen-swift` and `protoc-gen-grpc-swift` `protoc` plugins
+/// Derive the expected output file path to match the behavior of the `protoc-gen-swift`
-/// when using the `FullPath` naming scheme.
+/// and `protoc-gen-grpc-swift-2` `protoc` plugins using the `PathToUnderscores` naming scheme.
+///
+/// This means the generated file for an input proto file called "foo/bar/baz.proto" will
+/// have the name "foo\_bar\_baz.proto".
+///
 /// - Parameters:
-///   - inputFile: The input `.proto` file.
+///   - protoFile: The path of the input `.proto` file.
-///   - baseDirectoryPath: The root path to the source `.proto` files used as the reference for relative path naming schemes.
+///   - baseDirectoryPath: The root path to the source `.proto` files used as the reference for
+///     relative path naming schemes.
 ///   - outputDirectory: The directory in which generated source files are created.
 ///   - outputExtension: The file extension to be appended to generated files in-place of `.proto`.
 /// - Returns: The expected output file path.
 func deriveOutputFilePath(
-  for inputFile: URL,
+  protoFile: URL,
   baseDirectoryPath: URL,
   outputDirectory: URL,
   outputExtension: String
 ) -> URL {
-  // The name of the output file is based on the name of the input file.
+  // Replace the extension (".proto") with the new extension (".grpc.swift"
-  // We validated in the beginning that every file has the suffix of .proto
+  // or ".pb.swift").
-  // This means we can just drop the last 5 elements and append the new suffix
+  precondition(protoFile.pathExtension == "proto")
-  let lastPathComponentRoot = inputFile.lastPathComponent.dropLast(5)
+  let fileName = String(protoFile.lastPathComponent.dropLast(5) + outputExtension)
-  let lastPathComponent = String(lastPathComponentRoot + outputExtension)
 
   // find the inputFile path relative to the proto directory
-  var relativePathComponents = inputFile.deletingLastPathComponent().pathComponents
+  var relativePathComponents = protoFile.deletingLastPathComponent().pathComponents
   for protoDirectoryPathComponent in baseDirectoryPath.pathComponents {
     if relativePathComponents.first == protoDirectoryPathComponent {
       relativePathComponents.removeFirst()
@@ -297,10 +299,7 @@ func deriveOutputFilePath(
     }
   }
 
-  let outputFileComponents = relativePathComponents + [lastPathComponent]
+  relativePathComponents.append(fileName)
-  var outputFilePath = outputDirectory
+  let path = relativePathComponents.joined(separator: "_")
-  for outputFileComponent in outputFileComponents {
+  return outputDirectory.appending(path: path)
-    outputFilePath.append(component: outputFileComponent)
-  }
-  return outputFilePath
 }

Plugins/GRPCProtobufGeneratorCommand/CommandConfig.swift

@@ -0,0 +1,255 @@
+/*
+ * Copyright 2024, gRPC Authors All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import Foundation
+import PackagePlugin
+
+struct CommandConfig {
+  var common: GenerationConfig
+
+  var verbose: Bool
+  var dryRun: Bool
+
+  static let defaults = Self(
+    common: .init(
+      accessLevel: .internal,
+      servers: true,
+      clients: true,
+      messages: true,
+      fileNaming: .fullPath,
+      accessLevelOnImports: false,
+      importPaths: [],
+      outputPath: ""
+    ),
+    verbose: false,
+    dryRun: false
+  )
+
+  static let parameterGroupSeparator = "--"
+}
+
+extension CommandConfig {
+  static func parse(
+    argumentExtractor argExtractor: inout ArgumentExtractor,
+    pluginWorkDirectory: URL
+  ) throws -> CommandConfig {
+    var config = CommandConfig.defaults
+
+    for flag in OptionsAndFlags.allCases {
+      switch flag {
+      case .accessLevel:
+        if let value = argExtractor.extractSingleOption(named: flag.rawValue) {
+          if let accessLevel = GenerationConfig.AccessLevel(rawValue: value) {
+            config.common.accessLevel = accessLevel
+          } else {
+            throw CommandPluginError.unknownAccessLevel(value)
+          }
+        }
+
+      case .noServers:
+        // Handled by `.servers`
+        continue
+      case .servers:
+        let servers = argExtractor.extractFlag(named: OptionsAndFlags.servers.rawValue)
+        let noServers = argExtractor.extractFlag(named: OptionsAndFlags.noServers.rawValue)
+        if servers > 0 && noServers > 0 {
+          throw CommandPluginError.conflictingFlags(
+            OptionsAndFlags.servers.rawValue,
+            OptionsAndFlags.noServers.rawValue
+          )
+        } else if servers > 0 {
+          config.common.servers = true
+        } else if noServers > 0 {
+          config.common.servers = false
+        }
+
+      case .noClients:
+        // Handled by `.clients`
+        continue
+      case .clients:
+        let clients = argExtractor.extractFlag(named: OptionsAndFlags.clients.rawValue)
+        let noClients = argExtractor.extractFlag(named: OptionsAndFlags.noClients.rawValue)
+        if clients > 0 && noClients > 0 {
+          throw CommandPluginError.conflictingFlags(
+            OptionsAndFlags.clients.rawValue,
+            OptionsAndFlags.noClients.rawValue
+          )
+        } else if clients > 0 {
+          config.common.clients = true
+        } else if noClients > 0 {
+          config.common.clients = false
+        }
+
+      case .noMessages:
+        // Handled by `.messages`
+        continue
+      case .messages:
+        let messages = argExtractor.extractFlag(named: OptionsAndFlags.messages.rawValue)
+        let noMessages = argExtractor.extractFlag(named: OptionsAndFlags.noMessages.rawValue)
+        if messages > 0 && noMessages > 0 {
+          throw CommandPluginError.conflictingFlags(
+            OptionsAndFlags.messages.rawValue,
+            OptionsAndFlags.noMessages.rawValue
+          )
+        } else if messages > 0 {
+          config.common.messages = true
+        } else if noMessages > 0 {
+          config.common.messages = false
+        }
+
+      case .fileNaming:
+        if let value = argExtractor.extractSingleOption(named: flag.rawValue) {
+          if let fileNaming = GenerationConfig.FileNaming(rawValue: value) {
+            config.common.fileNaming = fileNaming
+          } else {
+            throw CommandPluginError.unknownFileNamingStrategy(value)
+          }
+        }
+
+      case .accessLevelOnImports:
+        if argExtractor.extractFlag(named: flag.rawValue) > 0 {
+          config.common.accessLevelOnImports = true
+        }
+
+      case .importPath:
+        config.common.importPaths = argExtractor.extractOption(named: flag.rawValue)
+
+      case .protocPath:
+        config.common.protocPath = argExtractor.extractSingleOption(named: flag.rawValue)
+
+      case .outputPath:
+        config.common.outputPath =
+          argExtractor.extractSingleOption(named: flag.rawValue)
+          ?? pluginWorkDirectory.absoluteStringNoScheme
+
+      case .verbose:
+        let verbose = argExtractor.extractFlag(named: flag.rawValue)
+        config.verbose = verbose != 0
+
+      case .dryRun:
+        let dryRun = argExtractor.extractFlag(named: flag.rawValue)
+        config.dryRun = dryRun != 0
+
+      case .help:
+        ()  // handled elsewhere
+      }
+    }
+
+    if let argument = argExtractor.remainingArguments.first {
+      throw CommandPluginError.unknownOption(argument)
+    }
+
+    return config
+  }
+}
+
+extension ArgumentExtractor {
+  mutating func extractSingleOption(named optionName: String) -> String? {
+    let values = self.extractOption(named: optionName)
+    if values.count > 1 {
+      Diagnostics.warning(
+        "'--\(optionName)' was unexpectedly repeated, the first value will be used."
+      )
+    }
+    return values.first
+  }
+}
+
+/// All valid input options/flags
+enum OptionsAndFlags: String, CaseIterable {
+  case servers
+  case noServers = "no-servers"
+  case clients
+  case noClients = "no-clients"
+  case messages
+  case noMessages = "no-messages"
+  case fileNaming = "file-naming"
+  case accessLevel = "access-level"
+  case accessLevelOnImports = "access-level-on-imports"
+  case importPath = "import-path"
+  case protocPath = "protoc-path"
+  case outputPath = "output-path"
+  case verbose
+  case dryRun = "dry-run"
+
+  case help
+}
+
+extension OptionsAndFlags {
+  func usageDescription() -> String {
+    switch self {
+    case .servers:
+      return "Generate server code. Generated by default."
+    case .noServers:
+      return "Do not generate server code. Generated by default."
+    case .clients:
+      return "Generate client code. Generated by default."
+    case .noClients:
+      return "Do not generate client code. Generated by default."
+    case .messages:
+      return "Generate message code. Generated by default."
+    case .noMessages:
+      return "Do not generate message code. Generated by default."
+    case .fileNaming:
+      return
+        "The naming scheme for output files [fullPath/pathToUnderscores/dropPath]. Defaults to fullPath."
+    case .accessLevel:
+      return
+        "The access level of the generated source [internal/public/package]. Defaults to internal."
+    case .accessLevelOnImports:
+      return "Whether imports should have explicit access levels. Defaults to false."
+    case .importPath:
+      return
+        "The directory in which to search for imports. May be specified multiple times. If none are specified the current working directory is used."
+    case .protocPath:
+      return "The path to the protoc binary."
+    case .dryRun:
+      return "Print but do not execute the protoc commands."
+    case .outputPath:
+      return "The directory into which the generated source files are created."
+    case .verbose:
+      return "Emit verbose output."
+    case .help:
+      return "Print this help."
+    }
+  }
+
+  static func printHelp(requested: Bool) {
+    let printMessage: (String) -> Void
+    if requested {
+      printMessage = { message in print(message) }
+    } else {
+      printMessage = Stderr.print
+    }
+
+    printMessage(
+      "Usage: swift package generate-grpc-code-from-protos [flags] [\(CommandConfig.parameterGroupSeparator)] [input files]"
+    )
+    printMessage("")
+    printMessage("Flags:")
+    printMessage("")
+
+    let spacing = 3
+    let maxLength =
+      (OptionsAndFlags.allCases.map(\.rawValue).max(by: { $0.count < $1.count })?.count ?? 0)
+      + spacing
+    for flag in OptionsAndFlags.allCases {
+      printMessage(
+        "  --\(flag.rawValue.padding(toLength: maxLength, withPad: " ", startingAt: 0))\(flag.usageDescription())"
+      )
+    }
+  }
+}

Plugins/GRPCProtobufGeneratorCommand/CommandPluginError.swift

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2025, gRPC Authors All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+enum CommandPluginError: Error {
+  case invalidArgumentValue(name: String, value: String)
+  case missingInputFile
+  case unknownOption(String)
+  case unknownAccessLevel(String)
+  case unknownFileNamingStrategy(String)
+  case conflictingFlags(String, String)
+  case generationFailure(
+    errorDescription: String,
+    executable: String,
+    arguments: [String],
+    stdErr: String?
+  )
+  case tooManyParameterSeparators
+}
+
+extension CommandPluginError: CustomStringConvertible {
+  var description: String {
+    switch self {
+    case .invalidArgumentValue(let name, let value):
+      return "Invalid value '\(value)', for '\(name)'."
+    case .missingInputFile:
+      return "No input file(s) specified."
+    case .unknownOption(let name):
+      return "Provided option is unknown: \(name)."
+    case .unknownAccessLevel(let value):
+      return "Provided access level is unknown: \(value)."
+    case .unknownFileNamingStrategy(let value):
+      return "Provided file naming strategy is unknown: \(value)."
+    case .conflictingFlags(let flag1, let flag2):
+      return "Provided flags conflict: '\(flag1)' and '\(flag2)'."
+    case .generationFailure(let errorDescription, let executable, let arguments, let stdErr):
+      var message = """
+        Code generation failed with: \(errorDescription).
+        \tExecutable: \(executable)
+        \tArguments: \(arguments.joined(separator: " "))
+        """
+      if let stdErr {
+        message += """
+          \n\tprotoc error output:
+          \t\(stdErr)
+          """
+      }
+      return message
+    case .tooManyParameterSeparators:
+      return "Unexpected parameter structure, too many '--' separators."
+    }
+  }
+}

Plugins/GRPCProtobufGeneratorCommand/Plugin.swift

@@ -0,0 +1,243 @@
+/*
+ * Copyright 2024, gRPC Authors All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import Foundation
+import PackagePlugin
+
+extension GRPCProtobufGeneratorCommandPlugin: CommandPlugin {
+  func performCommand(context: PluginContext, arguments: [String]) async throws {
+    try self.performCommand(
+      arguments: arguments,
+      tool: context.tool,
+      pluginWorkDirectoryURL: context.pluginWorkDirectoryURL
+    )
+  }
+}
+
+#if canImport(XcodeProjectPlugin)
+import XcodeProjectPlugin
+
+// Entry-point when using Xcode projects
+extension GRPCProtobufGeneratorCommandPlugin: XcodeCommandPlugin {
+  func performCommand(context: XcodeProjectPlugin.XcodePluginContext, arguments: [String]) throws {
+    try self.performCommand(
+      arguments: arguments,
+      tool: context.tool,
+      pluginWorkDirectoryURL: context.pluginWorkDirectoryURL
+    )
+  }
+}
+#endif
+
+@main
+struct GRPCProtobufGeneratorCommandPlugin {
+  /// Command plugin common code
+  func performCommand(
+    arguments: [String],
+    tool: (String) throws -> PluginContext.Tool,
+    pluginWorkDirectoryURL: URL
+  ) throws {
+    let flagsAndOptions: [String]
+    let inputFiles: [String]
+
+    let separatorCount = arguments.count { $0 == CommandConfig.parameterGroupSeparator }
+    switch separatorCount {
+    case 0:
+      var argExtractor = ArgumentExtractor(arguments)
+      // check if help requested
+      if argExtractor.extractFlag(named: OptionsAndFlags.help.rawValue) > 0 {
+        OptionsAndFlags.printHelp(requested: true)
+        return
+      }
+
+      inputFiles = arguments
+      flagsAndOptions = []
+
+    case 1:
+      let splitIndex = arguments.firstIndex(of: CommandConfig.parameterGroupSeparator)!
+      flagsAndOptions = Array(arguments[..<splitIndex])
+      inputFiles = Array(arguments[splitIndex.advanced(by: 1)...])
+
+    default:
+      throw CommandPluginError.tooManyParameterSeparators
+    }
+
+    var argExtractor = ArgumentExtractor(flagsAndOptions)
+    // help requested
+    if argExtractor.extractFlag(named: OptionsAndFlags.help.rawValue) > 0 {
+      OptionsAndFlags.printHelp(requested: true)
+      return
+    }
+
+    // MARK: Configuration
+    let commandConfig: CommandConfig
+    do {
+      commandConfig = try CommandConfig.parse(
+        argumentExtractor: &argExtractor,
+        pluginWorkDirectory: pluginWorkDirectoryURL
+      )
+    } catch {
+      throw error
+    }
+
+    if commandConfig.verbose {
+      Stderr.print("InputFiles: \(inputFiles.joined(separator: ", "))")
+    }
+
+    let config = commandConfig.common
+    let protocPath = try deriveProtocPath(using: config, tool: tool)
+    let protocGenGRPCSwiftPath = try tool("protoc-gen-grpc-swift-2").url
+    let protocGenSwiftPath = try tool("protoc-gen-swift").url
+
+    let outputDirectory = URL(fileURLWithPath: config.outputPath)
+    if commandConfig.verbose {
+      Stderr.print(
+        "Generated files will be written to: '\(outputDirectory.absoluteStringNoScheme)'"
+      )
+    }
+
+    let inputFileURLs = inputFiles.map { URL(fileURLWithPath: $0) }
+
+    // MARK: protoc-gen-grpc-swift-2
+    if config.clients || config.servers {
+      let arguments = constructProtocGenGRPCSwiftArguments(
+        config: config,
+        fileNaming: config.fileNaming,
+        inputFiles: inputFileURLs,
+        protoDirectoryPaths: config.importPaths,
+        protocGenGRPCSwiftPath: protocGenGRPCSwiftPath,
+        outputDirectory: outputDirectory
+      )
+
+      try executeProtocInvocation(
+        executableURL: protocPath,
+        arguments: arguments,
+        verbose: commandConfig.verbose,
+        dryRun: commandConfig.dryRun
+      )
+
+      if !commandConfig.dryRun, commandConfig.verbose {
+        Stderr.print("Generated gRPC Swift files for \(inputFiles.joined(separator: ", ")).")
+      }
+    }
+
+    // MARK: protoc-gen-swift
+    if config.messages {
+      let arguments = constructProtocGenSwiftArguments(
+        config: config,
+        fileNaming: config.fileNaming,
+        inputFiles: inputFileURLs,
+        protoDirectoryPaths: config.importPaths,
+        protocGenSwiftPath: protocGenSwiftPath,
+        outputDirectory: outputDirectory
+      )
+
+      try executeProtocInvocation(
+        executableURL: protocPath,
+        arguments: arguments,
+        verbose: commandConfig.verbose,
+        dryRun: commandConfig.dryRun
+      )
+
+      if !commandConfig.dryRun, commandConfig.verbose {
+        Stderr.print(
+          "Generated protobuf message Swift files for \(inputFiles.joined(separator: ", "))."
+        )
+      }
+    }
+  }
+}
+
+/// Execute a single invocation of `protoc`, printing output and if in verbose mode the invocation
+/// - Parameters:
+///   - executableURL: The path to the `protoc` executable.
+///   - arguments: The arguments to be passed to `protoc`.
+///   - verbose: Whether or not to print verbose output
+///   - dryRun: If this invocation is a dry-run, i.e. will not actually be executed
+func executeProtocInvocation(
+  executableURL: URL,
+  arguments: [String],
+  verbose: Bool,
+  dryRun: Bool
+) throws {
+  if verbose {
+    Stderr.print("\(executableURL.absoluteStringNoScheme) \\")
+    Stderr.print("  \(arguments.joined(separator: " \\\n  "))")
+  }
+
+  if dryRun {
+    return
+  }
+
+  let process = Process()
+  process.executableURL = executableURL
+  process.arguments = arguments
+
+  let outputPipe = Pipe()
+  let errorPipe = Pipe()
+  process.standardOutput = outputPipe
+  process.standardError = errorPipe
+
+  do {
+    try process.run()
+  } catch {
+    try printProtocOutput(outputPipe, verbose: verbose)
+    let stdErr: String?
+    if let errorData = try errorPipe.fileHandleForReading.readToEnd() {
+      stdErr = String(decoding: errorData, as: UTF8.self)
+    } else {
+      stdErr = nil
+    }
+    throw CommandPluginError.generationFailure(
+      errorDescription: "\(error)",
+      executable: executableURL.absoluteStringNoScheme,
+      arguments: arguments,
+      stdErr: stdErr
+    )
+  }
+  process.waitUntilExit()
+
+  try printProtocOutput(outputPipe, verbose: verbose)
+
+  if process.terminationReason == .exit && process.terminationStatus == 0 {
+    return
+  }
+
+  let stdErr: String?
+  if let errorData = try errorPipe.fileHandleForReading.readToEnd() {
+    stdErr = String(decoding: errorData, as: UTF8.self)
+  } else {
+    stdErr = nil
+  }
+  let problem = "\(process.terminationReason):\(process.terminationStatus)"
+  throw CommandPluginError.generationFailure(
+    errorDescription: problem,
+    executable: executableURL.absoluteStringNoScheme,
+    arguments: arguments,
+    stdErr: stdErr
+  )
+}
+
+func printProtocOutput(_ stdOut: Pipe, verbose: Bool) throws {
+  if verbose, let outputData = try stdOut.fileHandleForReading.readToEnd() {
+    let output = String(decoding: outputData, as: UTF8.self)
+    let lines = output.split { $0.isNewline }
+    print("protoc output:")
+    for line in lines {
+      print("\t\(line)")
+    }
+  }
+}

Plugins/GRPCProtobufGeneratorCommand/PluginsShared

@@ -0,0 +1 @@
+../PluginsShared

Plugins/PluginsShared/GenerationConfig.swift

@@ -32,7 +32,7 @@ struct GenerationConfig {
   /// - `FullPath`: `foo/bar/baz.grpc.swift`
   /// - `PathToUnderscore`: `foo_bar_baz.grpc.swift`
   /// - `DropPath`: `baz.grpc.swift`
-  enum FileNaming: String, Codable {
+  enum FileNaming: String {
     /// Replicate the input file path with the output file(s).
     case fullPath = "FullPath"
     /// Convert path directory delimiters to underscores.
@@ -42,13 +42,13 @@ struct GenerationConfig {
   }
 
   /// The visibility of the generated files.
-  var visibility: AccessLevel
+  var accessLevel: AccessLevel
   /// Whether server code is generated.
-  var server: Bool
+  var servers: Bool
   /// Whether client code is generated.
-  var client: Bool
+  var clients: Bool
   /// Whether message code is generated.
-  var message: Bool
+  var messages: Bool
   /// The naming of output files with respect to the path of the source file.
   var fileNaming: FileNaming
   /// Whether imports should have explicit access levels.
@@ -83,3 +83,18 @@ extension GenerationConfig.AccessLevel: Codable {
     }
   }
 }
+
+extension GenerationConfig.FileNaming: Codable {
+  init?(rawValue: String) {
+    switch rawValue.lowercased() {
+    case "fullpath":
+      self = .fullPath
+    case "pathtounderscores":
+      self = .pathToUnderscores
+    case "droppath":
+      self = .dropPath
+    default:
+      return nil
+    }
+  }
+}

Plugins/PluginsShared/PluginUtils.swift

@@ -17,6 +17,8 @@
 import Foundation
 import PackagePlugin
 
+let configFileName = "grpc-swift-proto-generator-config.json"
+
 /// Derive the path to the instance of `protoc` to be used.
 /// - Parameters:
 ///   - config: The supplied config. If no path is supplied then one is discovered using the `PROTOC_PATH` environment variable or the `findTool`.
@@ -63,7 +65,7 @@ func constructProtocGenSwiftArguments(
     protocArgs.append("--proto_path=\(path)")
   }
 
-  protocArgs.append("--swift_opt=Visibility=\(config.visibility.rawValue)")
+  protocArgs.append("--swift_opt=Visibility=\(config.accessLevel.rawValue)")
   protocArgs.append("--swift_opt=FileNaming=\(config.fileNaming.rawValue)")
   protocArgs.append("--swift_opt=UseAccessLevelOnImports=\(config.accessLevelOnImports)")
   protocArgs.append(contentsOf: inputFiles.map { $0.absoluteStringNoScheme })
@@ -71,15 +73,15 @@ func constructProtocGenSwiftArguments(
   return protocArgs
 }
 
-/// Construct the arguments to be passed to `protoc` when invoking the `protoc-gen-grpc-swift` `protoc` plugin.
+/// Construct the arguments to be passed to `protoc` when invoking the `protoc-gen-grpc-swift-2` `protoc` plugin.
 /// - Parameters:
 ///   - config: The config for this operation.
 ///   - fileNaming: The file naming scheme to be used.
 ///   - inputFiles: The input `.proto` files.
 ///   - protoDirectoryPaths: The directories in which `protoc` will look for imports.
-///   - protocGenGRPCSwiftPath: The path to the `protoc-gen-grpc-swift` `protoc` plugin.
+///   - protocGenGRPCSwiftPath: The path to the `protoc-gen-grpc-swift-2` `protoc` plugin.
 ///   - outputDirectory: The directory in which generated source files are created.
-/// - Returns: The constructed arguments to be passed to `protoc` when invoking the `protoc-gen-grpc-swift` `protoc` plugin.
+/// - Returns: The constructed arguments to be passed to `protoc` when invoking the `protoc-gen-grpc-swift-2` `protoc` plugin.
 func constructProtocGenGRPCSwiftArguments(
   config: GenerationConfig,
   fileNaming: GenerationConfig.FileNaming?,
@@ -97,9 +99,9 @@ func constructProtocGenGRPCSwiftArguments(
     protocArgs.append("--proto_path=\(path)")
   }
 
-  protocArgs.append("--grpc-swift_opt=Visibility=\(config.visibility.rawValue.capitalized)")
+  protocArgs.append("--grpc-swift_opt=Visibility=\(config.accessLevel.rawValue.capitalized)")
-  protocArgs.append("--grpc-swift_opt=Server=\(config.server)")
+  protocArgs.append("--grpc-swift_opt=Server=\(config.servers)")
-  protocArgs.append("--grpc-swift_opt=Client=\(config.client)")
+  protocArgs.append("--grpc-swift_opt=Client=\(config.clients)")
   protocArgs.append("--grpc-swift_opt=FileNaming=\(config.fileNaming.rawValue)")
   protocArgs.append("--grpc-swift_opt=UseAccessLevelOnImports=\(config.accessLevelOnImports)")
   protocArgs.append(contentsOf: inputFiles.map { $0.absoluteStringNoScheme })
@@ -117,3 +119,14 @@ extension URL {
     return absoluteString
   }
 }
+
+enum Stderr {
+  private static let newLine = "\n".data(using: .utf8)!
+
+  static func print(_ message: String) {
+    if let data = message.data(using: .utf8) {
+      FileHandle.standardError.write(data)
+      FileHandle.standardError.write(Self.newLine)
+    }
+  }
+}

README.md

@@ -14,5 +14,5 @@ for [gRPC Swift][gh-grpc-swift-protobuf].
 
 [gh-swift-protobuf]: https://github.com/apple/swift-protobuf
 [gh-grpc-swift-protobuf]: https://github.com/grpc/grpc-swift-protobuf
-[spi-grpc-swift]: https://swiftpackageindex.com/grpc/grpc-swift/documentation
+[spi-grpc-swift]: https://swiftpackageindex.com/grpc/grpc-swift-2/documentation
 [spi-grpc-swift-protobuf]: https://swiftpackageindex.com/grpc/grpc-swift-protobuf/documentation

Sources/CGRPCProtobuf/CGRPCProtobuf.c

@@ -0,0 +1,19 @@
+// Copyright 2025, gRPC Authors All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "CGRPCProtobuf.h"
+
+const char *cgrprc_grpc_swift_protobuf_version() {
+  return CGRPC_GRPC_SWIFT_PROTOBUF_VERSION;
+}

Sources/CGRPCProtobuf/include/CGRPCProtobuf.h

@@ -0,0 +1,20 @@
+// Copyright 2025, gRPC Authors All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CGRPC_PROTOBUF_H_
+#define CGRPC_PROTOBUF_H_
+
+const char *cgrprc_grpc_swift_protobuf_version();
+
+#endif  // CGRPC_PROTOBUF_H_

Sources/GRPCProtobuf/Coding.swift

@@ -18,6 +18,7 @@ public import GRPCCore
 public import SwiftProtobuf
 
 /// Serializes a Protobuf message into a sequence of bytes.
+@available(gRPCSwiftProtobuf 2.0, *)
 public struct ProtobufSerializer<Message: SwiftProtobuf.Message>: GRPCCore.MessageSerializer {
   public init() {}
 
@@ -41,6 +42,7 @@ public struct ProtobufSerializer<Message: SwiftProtobuf.Message>: GRPCCore.Messa
 }
 
 /// Deserializes a sequence of bytes into a Protobuf message.
+@available(gRPCSwiftProtobuf 2.0, *)
 public struct ProtobufDeserializer<Message: SwiftProtobuf.Message>: GRPCCore.MessageDeserializer {
   public init() {}
 

Sources/GRPCProtobuf/ContiguousBytesAdapter.swift

@@ -24,6 +24,7 @@ public import SwiftProtobuf  // internal but @usableFromInline
 /// it'd require a dependency on Protobuf in the core package), and `GRPCContiguousBytes` can't
 /// refine `SwiftProtobufContiguousBytes` for the same reason.
 @usableFromInline
+@available(gRPCSwiftProtobuf 2.0, *)
 struct ContiguousBytesAdapter<
   Bytes: GRPCContiguousBytes
 >: GRPCContiguousBytes, SwiftProtobufContiguousBytes {

Sources/GRPCProtobuf/Documentation.docc/Articles/API-stability-of-generated-code.md

@@ -0,0 +1,78 @@
+# API stability of generated code
+
+Understand the impact of changes you make to your Protocol Buffers files on the
+generated Swift code.
+
+## Overview
+
+The API of the generated code depends on three factors:
+
+- The contents of the source `.proto` file.
+- The options you use when generating the code.
+- The code generator (the `protoc-gen-grpc-swift-2` plugin for `protoc`).
+
+While this document applies specifically to the gRPC code generated and *not*
+code for messages used as inputs and outputs of each method, the concepts still
+broadly apply.
+
+Some of the concepts used in this document are described in more detail in
+<doc:Understanding-the-generated-code>.
+
+## The source .proto file
+
+The source `.proto` file defines the API of your service. You'll likely provide
+it to users so that they can generate clients from it. In order to maintain API
+stability for your service and for clients you must adhere to the following
+rules:
+
+1. You mustn't change the `package` the service is defined in.
+2. You mustn't change or add the `swift_prefix` option.
+3. You mustn't remove or change the name of any services in your `.proto` file.
+4. You mustn't remove or change the name of any RPCs in your `.proto` file.
+5. You mustn't change the message types used by any RPCs in your `.proto` file.
+
+Failure to follow these will result in changes in the generated code which can
+result in build failures for users.
+
+Whilst this sounds restrictive you may do the following:
+
+1. You may add a new RPC to an existing service in your `.proto` file.
+2. You may add a new service to your `.proto` file (however it is recommended
+   that you define a single service per `.proto` file).
+
+## The options you use for generating code
+
+Code you generate into your Swift Package becomes part of the API of your
+package. You must therefore ensure that downstream users of your package aren't
+impacted by the options you use when generating code.
+
+By default code is generated at the `internal` access level and therefore not
+part of the public API. You must explicitly opt in to generating code at the
+`public` access level. If you do this then you must be aware that changing what
+is generated (clients, servers) affects the public API, as does the access level
+of the generated code.
+
+If you need to validate whether your API has changed you can use tools like
+Swift Package Manager's API breakage diagnostic (`swift package
+diagnose-api-breaking-changes`.) In general you should prefer providing users
+with the service's `.proto` file so that they can generate clients, or provide a
+library which wraps the client to hide the API of the generated code.
+
+## The code generator
+
+The gRPC Swift maintainers may need to evolve the generated code over time. This
+will be done in a source-compatible way.
+
+If APIs are no longer suitable then they may be deprecated in favour of new
+ones. Within a major version of the package existing API won't be removed
+and deprecated APIs will continue to function.
+
+If the generator introduces new ways to generate code which are incompatible
+with the previously generated code then they will require explicit opt-in via an
+option.
+
+As gRPC Swift is developed the generated code may need to rely on newer
+functionality from its runtime counterparts (`GRPCCore` and `GRPCProtobuf`).
+This means that you should use the versions of `protoc-gen-grpc-swift-2` and
+`protoc-gen-swift` resolved with your package rather than getting them from an
+out-of-band (such as `homebrew`).

Sources/GRPCProtobuf/Documentation.docc/Articles/Generating-stubs.md

@@ -56,18 +56,18 @@ You must name the file `grpc-swift-proto-generator-config.json` and structure it
   "generate": {
     "clients": true,
     "servers": true,
-    "messages": true,
+    "messages": true
   },
   "generatedSource": {
     "accessLevelOnImports": false,
-    "accessLevel": "internal",
+    "accessLevel": "internal"
-  }
-  "protoc": {
-    "executablePath": "/opt/homebrew/bin/protoc"
-    "importPaths": [
-      "../directory_1",
-    ],
   },
+  "protoc": {
+    "executablePath": "/opt/homebrew/bin/protoc",
+    "importPaths": [
+      "../directory_1"
+    ]
+  }
 }
 ```
 
@@ -87,7 +87,7 @@ The options do not need to be specified and each have default values.
 
 ‡ If you don't provide any import paths then the path to the configuration file will be used on a per-source-file basis.
 
-Many of these options map to `protoc-gen-grpc-swift` and `protoc-gen-swift` options.
+Many of these options map to `protoc-gen-grpc-swift-2` and `protoc-gen-swift` options.
 
 If you require greater flexibility you may specify more than one configuration file.
 Configuration files apply to all `.proto` files equal to or below it in the file hierarchy. A configuration file
@@ -96,73 +96,82 @@ lower in the file hierarchy supersedes one above it.
 ### Using protoc
 
 The [`grpc-swift-protobuf`](https://github.com/grpc/grpc-swift-protobuf) package provides
-`protoc-gen-grpc-swift`, a program which is a plugin for the Protocol Buffers compiler, `protoc`.
+`protoc-gen-grpc-swift-2`, a program which is a plugin for the Protocol Buffers compiler, `protoc`.
 To generate gRPC stubs for your `.proto` files directly you must run the `protoc` command with
-the `--grpc-swift_out=<DIRECTORY>` option:
+the `--grpc-swift-2_out=<DIRECTORY>` option:
 
 ```console
-protoc --grpc-swift_out=. my-service.proto
+protoc --grpc-swift-2_out=. my-service.proto
 ```
 
-> `protoc-gen-grpc-swift` only generates gRPC stubs, it doesn't generate messages. You must use
+> `protoc-gen-grpc-swift-2` only generates gRPC stubs, it doesn't generate messages. You must use
 > `protoc-gen-swift` to generate messages in addition to gRPC Stubs.
 
-The presence of `--grpc-swift_out` tells `protoc` to use the `protoc-gen-grpc-swift` plugin. By
+The presence of `--grpc-swift-2_out` tells `protoc` to use the `protoc-gen-grpc-swift-2` plugin. By
 default it'll look for the plugin in your `PATH`. You can also specify the path to the plugin
 explicitly:
 
 ```console
-protoc --plugin=/path/to/protoc-gen-grpc-swift --grpc-swift_out=. my-service.proto
+protoc --plugin=/path/to/protoc-gen-grpc-swift-2 --grpc-swift-2_out=. my-service.proto
 ```
 
-You can also specify various option the `protoc-gen-grpc-swift` via `protoc` using
+You can also specify various option the `protoc-gen-grpc-swift-2` via `protoc` using
-the `--grpc-swift_opt` argument:
+the `--grpc-swift-2_opt` argument:
 
 ```console
-protoc --grpc-swift_opt=<OPTION_NAME>=<OPTION_VALUE> --grpc-swift_out=.
+protoc --grpc-swift-2_opt=<OPTION_NAME>=<OPTION_VALUE> --grpc-swift-2_out=.
 ```
 
-You can specify multiple options by passing the `--grpc-swift_opt` argument multiple times:
+You can specify multiple options by passing the `--grpc-swift-2_opt` argument multiple times:
 
 ```console
 protoc \
-  --grpc-swift_opt=<OPTION_NAME1>=<OPTION_VALUE1> \
+  --grpc-swift-2_opt=<OPTION_NAME1>=<OPTION_VALUE1> \
-  --grpc-swift_opt=<OPTION_NAME2>=<OPTION_VALUE2> \
+  --grpc-swift-2_opt=<OPTION_NAME2>=<OPTION_VALUE2> \
-  --grpc-swift_out=.
+  --grpc-swift-2_out=.
 ```
 
 #### Generator options
 
-| Name                      | Possible Values                            | Default    | Description                                              |
+| Name                      | Possible Values                             | Default         | Description                                              |
-|---------------------------|--------------------------------------------|------------|----------------------------------------------------------|
+|---------------------------|---------------------------------------------|-----------------|----------------------------------------------------------|
-| `Visibility`              | `Public`, `Package`, `Internal`            | `Internal` | Access level for generated stubs                         |
+| `Visibility`              | `Public`, `Package`, `Internal`             | `Internal`      | Access level for generated stubs                         |
-| `Server`                  | `True`, `False`                            | `True`     | Generate server stubs                                    |
+| `Server`                  | `True`, `False`                             | `True`          | Generate server stubs                                    |
-| `Client`                  | `True`, `False`                            | `True`     | Generate client stubs                                    |
+| `Client`                  | `True`, `False`                             | `True`          | Generate client stubs                                    |
-| `FileNaming`              | `FullPath`, `PathToUnderscore`, `DropPath` | `FullPath` | How generated source files should be named. (See below.) |
+| `FileNaming`              | `FullPath`, `PathToUnderscores`, `DropPath` | `FullPath`      | How generated source files should be named. †            |
-| `ProtoPathModuleMappings` |                                            |            | Path to module map `.asciipb` file. (See below.)         |
+| `ProtoPathModuleMappings` |                                             |                 | Path to module map `.asciipb` file. ‡                    |
-| `UseAccessLevelOnImports` | `True`, `False`                            | `False`    | Whether imports should have explicit access levels.      |
+| `UseAccessLevelOnImports` | `True`, `False`                             | `False`         | Whether imports should have explicit access levels.      |
+| `GRPCModuleName`          |                                             | `GRPCCore`      | The name of the `GRPCCore` module.                       |
+| `GRPCProtobufModuleName`  |                                             | `GRPCProtobuf`  | The name of the `GRPCProtobuf` module.                   |
+| `SwiftProtobufModuleName` |                                             | `SwiftProtobuf` | The name of the `SwiftProtobuf` module.                  |
+| `Availability`            | String, in the form `OS Version`            |                 | Platform availability to use in generated code. §        |
 
-The `FileNaming` option has three possible values, for an input of `foo/bar/baz.proto` the following
+† The `FileNaming` option has three possible values, for an input of `foo/bar/baz.proto` the following
 output file will be generated:
 - `FullPath`: `foo/bar/baz.grpc.swift`.
-- `PathToUnderscore`: `foo_bar_baz.grpc.swift`
+- `PathToUnderscores`: `foo_bar_baz.grpc.swift`
 - `DropPath`: `baz.grpc.swift`
 
-The code generator assumes all inputs are generated into the same module, `ProtoPathModuleMappings`
+‡ The code generator assumes all inputs are generated into the same module, `ProtoPathModuleMappings`
 allows you to specify a mapping from `.proto` files to the Swift module they are generated in. This
 allows the code generator to add appropriate imports to your generated stubs. This is described in
 more detail in the [SwiftProtobuf documentation](https://github.com/apple/swift-protobuf/blob/main/Documentation/PLUGIN.md).
 
+§ If unspecified the following availability is used: macOS 15, iOS 18, tvOS 18,
+watchOS 11, visionOS 2. The `Availability` option may be specified multiple
+times, where each value is a space delimited pair of platform and version, e.g.
+`Availability=macOS 15.0`.
+
 #### Building the protoc plugin
 
-> The version of `protoc-gen-grpc-swift` you use mustn't be newer than the version of
+> The version of `protoc-gen-grpc-swift-2` you use mustn't be newer than the version of
 > the `grpc-swift-protobuf` you're using.
 
-If your package depends on `grpc-swift-protobuf` then you can get a copy of `protoc-gen-grpc-swift`
+If your package depends on `grpc-swift-protobuf` then you can get a copy of `protoc-gen-grpc-swift-2`
 by building it directly:
 
 ```console
-swift build --product protoc-gen-grpc-swift
+swift build --product protoc-gen-grpc-swift-2
 ```
 
 This command will build the plugin into `.build/debug` directory. You can get the full path using

Sources/GRPCProtobuf/Documentation.docc/Articles/Public-services-with-private-implementations.md

@@ -0,0 +1,45 @@
+# Public services with private implementations
+
+Learn how to create a `public` gRPC service with private implementation details.
+
+## Overview
+
+It's not uncommon for a library to provide a gRPC service as part of its API.
+For example, the gRPC Swift Extras package provides implementations of the gRPC
+health and reflection services. Making the implementation of a service `public`
+would require its generated gRPC and message types to also be `public`. This is
+undesirable as it leaks implementation details into the public API of the
+package. This article explains how to keep the generated types private while
+making the service available as part of the public API.
+
+## Hiding the implementation
+
+You can hide the implementation details of your service by providing a wrapper
+type conforming to `RegistrableRPCService`. This is the protocol used by
+`GRPCServer` to register service methods with the server's router. Implementing
+`RegistrableRPCService` is straightforward and can delegate to the underlying
+service. This is demonstrated in the following code:
+
+```swift
+public struct GreeterService: RegistrableRPCService {
+  private var base: Greeter
+
+  public init() {
+    self.base = Greeter()
+  }
+
+  public func registerMethods<Transport>(
+    with router: inout RPCRouter<Transport>
+  ) where Transport: ServerTransport {
+    self.base.registerMethods(with: &router)
+  }
+}
+```
+
+In this example `Greeter` implements the underlying service and would conform to
+the generated service protocol but would have a non-public access level.
+`GreeterService` is a public wrapper type conforming to `RegistrableRPCService`
+which implements its only requirement, `registerMethods(with:)`, by calling
+through to the underlying implementation. The result is a service which can be
+registered with a server where none of the generated types are part of the
+public API.

Sources/GRPCProtobuf/Documentation.docc/Articles/Understanding-the-generated-code.md

@@ -0,0 +1,143 @@
+# Understanding the generated code
+
+Understand what code is generated by `protoc-gen-grpc-swift-2` from a `.proto`
+file and how to use it.
+
+## Overview
+
+The gRPC Swift Protobuf package provides a plugin to the Protocol Buffers
+Compiler (`protoc`) called `protoc-gen-grpc-swift-2`. The plugin is responsible
+for generating the gRPC specific code for services defined in a `.proto` file.
+
+### Package namespace
+
+Most `.proto` files contain a `package` directive near the start of the file
+describing the namespace it belongs to. Here's an example:
+
+```proto
+package foo.bar.v1;
+```
+
+The package name "foo.bar.v1" is important as it is used as a prefix for
+generated types. The default behaviour is to replace periods with underscores
+and to capitalize each word and add a trailing underscore. For this package the
+prefix is "Foo\_Bar\_V1\_". If you don't declare a package then the prefix will be
+the empty string.
+
+You can override the prefix by setting the `swift_prefix` option:
+
+```proto
+option swift_prefix = "FooBarV1";
+
+package foo.bar.v1;
+```
+
+The prefix for types in this file would be "FooBarV1" instead of "Foo\_Bar\_V1\_".
+
+### Service namespace
+
+For each service declared in your `.proto` file, gRPC will generate a caseless
+`enum` which is a namespace holding the generated protocols and types. The name
+of this `enum` is `{PREFIX}{SERVICE}` where `{PREFIX}` is as described in the
+previous section and `{SERVICE}` is the name of the service as declared in the
+`.proto` file.
+
+As an example the following definition creates a service namespace `enum` called
+`Foo_Bar_V1_BazService` (the `{PREFIX}` is "Foo_Bar_V1_" and `{SERVICE}` is
+"BazService"):
+
+```proto
+package foo.bar.v1;
+
+service BazService {
+  // ...
+}
+```
+
+Code generated for each service falls into three categories:
+
+1. Service metadata,
+2. Service code, and
+3. Client code.
+
+#### Service metadata
+
+gRPC generates metadata for each service including a descriptor identifying the
+fully qualified name of the service and information about each method in the
+service. You likely won't need to interact directly with this information but
+it's available should you need to.
+
+#### Service code
+
+Within a service namespace gRPC generates three service protocols:
+
+1. `StreamingServiceProtocol`,
+2. `ServiceProtocol`, and
+3. `SimpleServiceProtocol`.
+
+The full name of each protocol includes the service namespace.
+
+> Example:
+>
+> For the `BazService` in the `foo.bar.v1` package the protocols would be:
+>
+> - `Foo_Bar_V1_BazService.StreamingServiceProtocol`,
+> - `Foo_Bar_V1_BazService.ServiceProtocol`, and
+> - `Foo_Bar_V1_BazService.SimpleServiceProtocol`.
+
+Each of these protocols mirror the `service` defined in your `.proto` file with
+one requirement per RPC. To implement your service you must implement one of
+these protocols.
+
+The protocols form a hierarchy with `StreamingServiceProtocol` at the bottom and
+`SimpleServiceProtocol` at the top. `ServiceProtocol` refines
+`StreamingServiceProtocol`, and `SimpleServiceProtocol` refines
+`ServiceProtocol` (and `StreamingServiceProtocol` in turn).
+
+The `StreamingServiceProtocol` implements each RPC as if it were a bidirectional
+streaming RPC. This gives you the most flexibility at the cost of a harder to
+implement API. It also puts the responsibility on you to ensure that each RPC
+sends and receives the correct number of messages.
+
+The `ServiceProtocol` enforces that the correct number of messages are sent and
+received via its API. It also allows you to read request metadata and send both
+initial and trailing metadata. The request and response types for these
+requirements are in terms of `ServerRequest` and `ServerResponse`.
+
+The `SimpleServiceProtocol` also enforces the correct number of messages are
+sent and received via its API. However, it isn't defined in terms of
+`ServerRequest` or `ServerResponse` so it doesn't allow you access metadata.
+This limitation allows it to have the simplest API and is preferred if you don't
+need access to metadata.
+
+| Protocol                   | Enforces number of messages | Access to metadata
+|----------------------------|-----------------------------|-------------------
+| `StreamingServiceProtocol` | ✗                           | ✓
+| `ServiceProtocol`          | ✓                           | ✓
+| `SimpleServiceProtocol`    | ✓                           | ✗
+
+#### Client code
+
+gRPC generates two types for the client within a service namespace:
+
+1. `ClientProtocol`, and
+2. `Client`.
+
+Like the service code, the full name includes the namespace.
+
+> Example:
+>
+> For the `BazService` in the `foo.bar.v1` package the client types would be:
+>
+> - `Foo_Bar_V1_BazService.ClientProtocol`, and
+> - `Foo_Bar_V1_BazService.Client`.
+
+The `ClientProtocol` defines one requirement for each RPC in terms of
+`ClientRequest` and `ClientResponse`. You don't need to implement the protocol
+as `Client` provides a concrete implementation.
+
+gRPC also generates extensions on `ClientProtocol` to provide more ergonomic
+APIs. These include versions which provide default arguments for various
+parameters (like the message serializer and deserializers; call options and
+response handler) and versions which don't use `ClientRequest` and
+`ClientResponse` directly.

Sources/GRPCProtobuf/Documentation.docc/Documentation.md

@@ -7,7 +7,7 @@ A package integrating Swift Protobuf with gRPC Swift.
 This package provides three products:
 - ``GRPCProtobuf``, a module providing runtime serialization and deserialization components for
   [SwiftProtobuf](https://github.com/apple/swift-protobuf).
-- `protoc-gen-grpc-swift`, an executable which is a plugin for `protoc`, the Protocol Buffers
+- `protoc-gen-grpc-swift-2`, an executable which is a plugin for `protoc`, the Protocol Buffers
   compiler. An article describing how to generate gRPC Swift stubs using it is available with the
   `grpc-swift` documentation on the [Swift Package
   Index](https://swiftpackageindex.com/grpc/grpc-swift/documentation).
@@ -21,6 +21,9 @@ This package provides three products:
 
 - <doc:Installing-protoc>
 - <doc:Generating-stubs>
+- <doc:API-stability-of-generated-code>
+- <doc:Understanding-the-generated-code>
+- <doc:Public-services-with-private-implementations>
 
 ### Serialization
 

Sources/GRPCProtobuf/Errors/ErrorDetails+AnyPacking.swift

@@ -61,6 +61,7 @@ extension Google_Protobuf_Any {
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails {
   // Note: this type isn't packable into an 'Any' protobuf so doesn't conform
   // to 'GoogleProtobufAnyPackable' despite holding types which are packable.

Sources/GRPCProtobuf/Errors/ErrorDetails+CustomStringConvertible.swift

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails: CustomStringConvertible {
   public var description: String {
     switch self.wrapped {
@@ -46,54 +47,63 @@ extension ErrorDetails: CustomStringConvertible {
 // Some errors use protobuf messages as their storage so the default description isn't
 // representative
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.ErrorInfo: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(reason: \"\(self.reason)\", domain: \"\(self.domain)\", metadata: \(self.metadata))"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.DebugInfo: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(stack: \(self.stack), detail: \"\(self.detail)\")"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.QuotaFailure.Violation: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(subject: \"\(self.subject)\", violationDescription: \"\(self.violationDescription)\")"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.PreconditionFailure.Violation: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(subject: \"\(self.subject)\", type: \"\(self.type)\", violationDescription: \"\(self.violationDescription)\")"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.BadRequest.FieldViolation: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(field: \"\(self.field)\", violationDescription: \"\(self.violationDescription)\")"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.RequestInfo: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(requestID: \"\(self.requestID)\", servingData: \"\(self.servingData)\")"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.ResourceInfo: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(name: \"\(self.name)\", owner: \"\(self.owner)\", type: \"\(self.type)\", errorDescription: \"\(self.errorDescription)\")"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.Help.Link: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(url: \"\(self.url)\", linkDescription: \"\(self.linkDescription)\")"
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.LocalizedMessage: CustomStringConvertible {
   public var description: String {
     "\(Self.self)(locale: \"\(self.locale)\", message: \"\(self.message)\")"

Sources/GRPCProtobuf/Errors/ErrorDetails+Types.swift

@@ -16,6 +16,7 @@
 
 internal import SwiftProtobuf
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails {
   /// Describes the cause of the error with structured details.
   ///

Sources/GRPCProtobuf/Errors/ErrorDetails.swift

@@ -24,6 +24,7 @@ public import SwiftProtobuf
 ///
 /// This type also allows you to provide wrap your own error details up as an "Any"
 /// protobuf (`Google_Protobuf_Any`).
+@available(gRPCSwiftProtobuf 2.0, *)
 public struct ErrorDetails: Sendable, Hashable {
   enum Wrapped: Sendable, Hashable {
     case errorInfo(ErrorInfo)
@@ -198,6 +199,7 @@ public struct ErrorDetails: Sendable, Hashable {
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails {
   /// Returns error info if set.
   public var errorInfo: ErrorInfo? {

Sources/GRPCProtobuf/Errors/GoogleRPCStatus.swift

@@ -15,7 +15,7 @@
  */
 
 public import GRPCCore
-internal import SwiftProtobuf
+public import SwiftProtobuf
 
 /// An error containing structured details which can be delivered to the client.
 ///
@@ -33,10 +33,10 @@ internal import SwiftProtobuf
 /// >
 /// > The error information is transmitted to clients in the trailing metadata of an RPC. It is
 /// > inserted into the metadata keyed by "grpc-status-details-bin". The value of the metadata is
-/// > the serialized bytes of a "google.protobuf.Any" protocol buffers message. The content of which
+/// > the serialized bytes of a "google.rpc.Status" protocol buffers message containing the status
-/// > is a "google.rpc.Status" protocol buffers message containing the status code, message, and
+/// > code, message, and details.
-/// > details.
+@available(gRPCSwiftProtobuf 2.0, *)
-public struct GoogleRPCStatus: Error {
+public struct GoogleRPCStatus: Error, Hashable {
   /// A code representing the high-level domain of the error.
   public var code: RPCError.Code
 
@@ -74,13 +74,33 @@ public struct GoogleRPCStatus: Error {
   }
 }
 
-extension GoogleRPCStatus: GoogleProtobufAnyPackable {
+@available(gRPCSwiftProtobuf 2.0, *)
-  // See https://protobuf.dev/programming-guides/proto3/#any
+extension GoogleRPCStatus {
-  internal static var typeURL: String { "type.googleapis.com/google.rpc.Status" }
+  /// Creates a new message by decoding the given `SwiftProtobufContiguousBytes` value
-
+  /// containing a serialized message in Protocol Buffer binary format.
-  init?(unpacking any: Google_Protobuf_Any) throws {
+  ///
-    guard any.isA(Google_Rpc_Status.self) else { return nil }
+  /// - Parameters:
-    let status = try Google_Rpc_Status(serializedBytes: any.value)
+  ///   - bytes: The binary-encoded message data to decode.
+  ///   - extensions: An `ExtensionMap` used to look up and decode any
+  ///     extensions in this message or messages nested within this message's
+  ///     fields.
+  ///   - partial: If `false` (the default), this method will check if the `Message`
+  ///      is initialized after decoding to verify that all required fields are present.
+  ///      If any are missing, this method throws `BinaryDecodingError`.
+  ///   - options: The `BinaryDecodingOptions` to use.
+  /// - Throws: `BinaryDecodingError` if decoding fails.
+  public init<Bytes: SwiftProtobufContiguousBytes>(
+    serializedBytes bytes: Bytes,
+    extensions: (any ExtensionMap)? = nil,
+    partial: Bool = false,
+    options: BinaryDecodingOptions = BinaryDecodingOptions()
+  ) throws {
+    let status = try Google_Rpc_Status(
+      serializedBytes: bytes,
+      extensions: extensions,
+      partial: partial,
+      options: options
+    )
 
     let statusCode = Status.Code(rawValue: Int(status.code))
     self.code = statusCode.flatMap { RPCError.Code($0) } ?? .unknown
@@ -88,27 +108,40 @@ extension GoogleRPCStatus: GoogleProtobufAnyPackable {
     self.details = try status.details.map { try ErrorDetails(unpacking: $0) }
   }
 
-  func pack() throws -> Google_Protobuf_Any {
+  /// Returns a `SwiftProtobufContiguousBytes` instance containing the Protocol Buffer binary
+  /// format serialization of the message.
+  ///
+  /// - Parameters:
+  ///   - partial: If `false` (the default), this method will check
+  ///     `Message.isInitialized` before encoding to verify that all required
+  ///     fields are present. If any are missing, this method throws.
+  ///     `BinaryEncodingError/missingRequiredFields`.
+  ///   - options: The `BinaryEncodingOptions` to use.
+  /// - Returns: A `SwiftProtobufContiguousBytes` instance containing the binary serialization
+  /// of the message.
+  ///
+  /// - Throws: `SwiftProtobufError` or `BinaryEncodingError` if encoding fails.
+  public func serializedBytes<Bytes: SwiftProtobufContiguousBytes>(
+    partial: Bool = false,
+    options: BinaryEncodingOptions = BinaryEncodingOptions()
+  ) throws -> Bytes {
     let status = try Google_Rpc_Status.with {
       $0.code = Int32(self.code.rawValue)
       $0.message = self.message
       $0.details = try self.details.map { try $0.pack() }
     }
 
-    return try .with {
+    return try status.serializedBytes(partial: partial, options: options)
-      $0.typeURL = Self.typeURL
-      $0.value = try status.serializedBytes()
-    }
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension GoogleRPCStatus: RPCErrorConvertible {
   public var rpcErrorCode: RPCError.Code { self.code }
   public var rpcErrorMessage: String { self.message }
   public var rpcErrorMetadata: Metadata {
     do {
-      let any = try self.pack()
+      let bytes: [UInt8] = try self.serializedBytes()
-      let bytes: [UInt8] = try any.serializedBytes()
       return [Metadata.statusDetailsBinKey: .binary(bytes)]
     } catch {
       // Failed to serialize error details. Not a lot can be done here.

Sources/GRPCProtobuf/Errors/RPCError+GoogleRPCStatus.swift

@@ -17,10 +17,12 @@
 public import GRPCCore
 internal import SwiftProtobuf
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension Metadata {
   static let statusDetailsBinKey = "grpc-status-details-bin"
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension RPCError {
   /// Unpack a ``GoogleRPCStatus`` error from the error metadata.
   ///
@@ -31,8 +33,6 @@ extension RPCError {
   public func unpackGoogleRPCStatus() throws -> GoogleRPCStatus? {
     let values = self.metadata[binaryValues: Metadata.statusDetailsBinKey]
     guard let bytes = values.first(where: { _ in true }) else { return nil }
-
+    return try GoogleRPCStatus(serializedBytes: bytes)
-    let any = try Google_Protobuf_Any(serializedBytes: bytes)
-    return try GoogleRPCStatus(unpacking: any)
   }
 }

Sources/GRPCProtobufCodeGen/ProtobufCodeGenParser.swift

@@ -32,19 +32,23 @@ internal import struct Foundation.IndexPath
 #endif
 
 /// Parses a ``FileDescriptor`` object into a ``CodeGenerationRequest`` object.
+@available(gRPCSwiftProtobuf 2.0, *)
 package struct ProtobufCodeGenParser {
   let extraModuleImports: [String]
   let protoToModuleMappings: ProtoFileToModuleMappings
   let accessLevel: CodeGenerator.Config.AccessLevel
+  let moduleNames: ProtobufCodeGenerator.Config.ModuleNames
 
   package init(
     protoFileModuleMappings: ProtoFileToModuleMappings,
     extraModuleImports: [String],
-    accessLevel: CodeGenerator.Config.AccessLevel
+    accessLevel: CodeGenerator.Config.AccessLevel,
+    moduleNames: ProtobufCodeGenerator.Config.ModuleNames
   ) {
     self.extraModuleImports = extraModuleImports
     self.protoToModuleMappings = protoFileModuleMappings
     self.accessLevel = accessLevel
+    self.moduleNames = moduleNames
   }
 
   package func parse(descriptor: FileDescriptor) throws -> CodeGenerationRequest {
@@ -62,6 +66,7 @@ package struct ProtobufCodeGenParser {
     let leadingTrivia = """
       // DO NOT EDIT.
       // swift-format-ignore-file
+      // swiftlint:disable all
       //
       // Generated by the gRPC Swift generator plugin for the protocol buffer compiler.
       // Source: \(descriptor.name)
@@ -86,15 +91,16 @@ package struct ProtobufCodeGenParser {
       dependencies: self.codeDependencies(file: descriptor),
       services: services,
       makeSerializerCodeSnippet: { messageType in
-        "GRPCProtobuf.ProtobufSerializer<\(messageType)>()"
+        "\(self.moduleNames.grpcProtobuf).ProtobufSerializer<\(messageType)>()"
       },
       makeDeserializerCodeSnippet: { messageType in
-        "GRPCProtobuf.ProtobufDeserializer<\(messageType)>()"
+        "\(self.moduleNames.grpcProtobuf).ProtobufDeserializer<\(messageType)>()"
       }
     )
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ProtobufCodeGenParser {
   fileprivate func codeDependencies(file: FileDescriptor) -> [Dependency] {
     guard file.services.count > 0 else {
@@ -102,7 +108,7 @@ extension ProtobufCodeGenParser {
     }
 
     var codeDependencies: [Dependency] = [
-      Dependency(module: "GRPCProtobuf", accessLevel: .internal)
+      Dependency(module: self.moduleNames.grpcProtobuf, accessLevel: .internal)
     ]
     // If there's a dependency on a bundled proto then add the SwiftProtobuf import.
     //
@@ -113,7 +119,11 @@ extension ProtobufCodeGenParser {
     }
 
     if dependsOnBundledProto {
-      codeDependencies.append(Dependency(module: "SwiftProtobuf", accessLevel: self.accessLevel))
+      let dependency = Dependency(
+        module: self.moduleNames.swiftProtobuf,
+        accessLevel: self.accessLevel
+      )
+      codeDependencies.append(dependency)
     }
 
     // Adding as dependencies the modules containing generated code or types for
@@ -133,6 +143,7 @@ extension ProtobufCodeGenParser {
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension GRPCCodeGen.ServiceDescriptor {
   fileprivate init(
     descriptor: SwiftProtobufPluginLibrary.ServiceDescriptor,
@@ -160,6 +171,7 @@ extension GRPCCodeGen.ServiceDescriptor {
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension GRPCCodeGen.MethodDescriptor {
   fileprivate init(
     descriptor: SwiftProtobufPluginLibrary.MethodDescriptor,

Sources/GRPCProtobufCodeGen/ProtobufCodeGenerator.swift

@@ -17,11 +17,12 @@
 package import GRPCCodeGen
 package import SwiftProtobufPluginLibrary
 
+@available(gRPCSwiftProtobuf 2.0, *)
 package struct ProtobufCodeGenerator {
-  internal var config: GRPCCodeGen.CodeGenerator.Config
+  internal var config: ProtobufCodeGenerator.Config
 
   package init(
-    config: GRPCCodeGen.CodeGenerator.Config
+    config: ProtobufCodeGenerator.Config
   ) {
     self.config = config
   }
@@ -29,17 +30,76 @@ package struct ProtobufCodeGenerator {
   package func generateCode(
     fileDescriptor: FileDescriptor,
     protoFileModuleMappings: ProtoFileToModuleMappings,
-    extraModuleImports: [String]
+    extraModuleImports: [String],
+    availabilityOverrides: [(os: String, version: String)] = []
   ) throws -> String {
     let parser = ProtobufCodeGenParser(
       protoFileModuleMappings: protoFileModuleMappings,
       extraModuleImports: extraModuleImports,
-      accessLevel: self.config.accessLevel
+      accessLevel: self.config.accessLevel,
+      moduleNames: self.config.moduleNames
     )
-    let codeGenerator = GRPCCodeGen.CodeGenerator(config: self.config)
+
+    var codeGeneratorConfig = GRPCCodeGen.CodeGenerator.Config(
+      accessLevel: self.config.accessLevel,
+      accessLevelOnImports: self.config.accessLevelOnImports,
+      client: self.config.generateClient,
+      server: self.config.generateServer,
+      indentation: self.config.indentation
+    )
+    codeGeneratorConfig.grpcCoreModuleName = self.config.moduleNames.grpcCore
+
+    if availabilityOverrides.isEmpty {
+      codeGeneratorConfig.availability = .default
+    } else {
+      codeGeneratorConfig.availability = .custom(
+        availabilityOverrides.map { (os, version) in
+          .init(os: os, version: version)
+        }
+      )
+    }
+
+    let codeGenerator = GRPCCodeGen.CodeGenerator(config: codeGeneratorConfig)
 
     let codeGenerationRequest = try parser.parse(descriptor: fileDescriptor)
     let sourceFile = try codeGenerator.generate(codeGenerationRequest)
     return sourceFile.contents
   }
 }
+
+@available(gRPCSwiftProtobuf 2.0, *)
+extension ProtobufCodeGenerator {
+  package struct Config {
+    package var accessLevel: GRPCCodeGen.CodeGenerator.Config.AccessLevel
+    package var accessLevelOnImports: Bool
+
+    package var generateClient: Bool
+    package var generateServer: Bool
+
+    package var indentation: Int
+    package var moduleNames: ModuleNames
+
+    package struct ModuleNames {
+      package var grpcCore: String
+      package var grpcProtobuf: String
+      package var swiftProtobuf: String
+
+      package static let defaults = Self(
+        grpcCore: "GRPCCore",
+        grpcProtobuf: "GRPCProtobuf",
+        swiftProtobuf: "SwiftProtobuf"
+      )
+    }
+
+    package static var defaults: Self {
+      Self(
+        accessLevel: .internal,
+        accessLevelOnImports: false,
+        generateClient: true,
+        generateServer: true,
+        indentation: 4,
+        moduleNames: .defaults
+      )
+    }
+  }
+}

Sources/protoc-gen-grpc-swift-2/GenerateGRPC.swift

@@ -26,6 +26,7 @@ import Foundation
 #endif
 
 @main
+@available(gRPCSwiftProtobuf 2.0, *)
 final class GenerateGRPC: SwiftProtobufPluginLibrary.CodeGenerator {
   var version: String? {
     Version.versionString
@@ -55,37 +56,10 @@ final class GenerateGRPC: SwiftProtobufPluginLibrary.CodeGenerator {
     let options = try GeneratorOptions(parameter: parameter)
 
     for descriptor in fileDescriptors {
-      if options.generateReflectionData {
-        try self.generateReflectionData(
-          descriptor,
-          options: options,
-          outputs: outputs
-        )
-      }
-
       try self.generateV2Stubs(descriptor, options: options, outputs: outputs)
     }
   }
 
-  private func generateReflectionData(
-    _ descriptor: FileDescriptor,
-    options: GeneratorOptions,
-    outputs: any GeneratorOutputs
-  ) throws {
-    let fileName = self.uniqueOutputFileName(
-      fileDescriptor: descriptor,
-      fileNamingOption: options.fileNaming,
-      extension: "reflection"
-    )
-
-    var options = ExtractProtoOptions()
-    options.includeSourceCodeInfo = true
-    let proto = descriptor.extractProto(options: options)
-    let serializedProto = try proto.serializedData()
-    let reflectionData = serializedProto.base64EncodedString()
-    try outputs.add(fileName: fileName, contents: reflectionData)
-  }
-
   private func generateV2Stubs(
     _ descriptor: FileDescriptor,
     options: GeneratorOptions,
@@ -96,18 +70,19 @@ final class GenerateGRPC: SwiftProtobufPluginLibrary.CodeGenerator {
       fileNamingOption: options.fileNaming
     )
 
-    let config = CodeGenerator.Config(options: options)
+    let fileGenerator = ProtobufCodeGenerator(config: options.config)
-    let fileGenerator = ProtobufCodeGenerator(config: config)
     let contents = try fileGenerator.generateCode(
       fileDescriptor: descriptor,
       protoFileModuleMappings: options.protoToModuleMappings,
-      extraModuleImports: options.extraModuleImports
+      extraModuleImports: options.extraModuleImports,
+      availabilityOverrides: options.availabilityOverrides
     )
 
     try outputs.add(fileName: fileName, contents: contents)
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension GenerateGRPC {
   private func uniqueOutputFileName(
     fileDescriptor: FileDescriptor,
@@ -181,24 +156,3 @@ private func splitPath(pathname: String) -> (dir: String, base: String, suffix:
   }
   return (dir: dir, base: base, suffix: suffix)
 }
-
-extension GRPCCodeGen.CodeGenerator.Config {
-  init(options: GeneratorOptions) {
-    let accessLevel: GRPCCodeGen.CodeGenerator.Config.AccessLevel
-    switch options.visibility {
-    case .internal:
-      accessLevel = .internal
-    case .package:
-      accessLevel = .package
-    case .public:
-      accessLevel = .public
-    }
-
-    self.init(
-      accessLevel: accessLevel,
-      accessLevelOnImports: options.useAccessLevelOnImports,
-      client: options.generateClient,
-      server: options.generateServer
-    )
-  }
-}

Sources/protoc-gen-grpc-swift-2/Options.swift

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import GRPCCodeGen
+import GRPCProtobufCodeGen
 import SwiftProtobufPluginLibrary
 
 enum GenerationError: Error, CustomStringConvertible {
@@ -23,6 +25,8 @@ enum GenerationError: Error, CustomStringConvertible {
   case invalidParameterValue(name: String, value: String)
   /// Raised to wrap another error but provide a context message.
   case wrappedError(message: String, error: any Error)
+  /// The parameter isn't supported.
+  case unsupportedParameter(name: String, message: String)
 
   var description: String {
     switch self {
@@ -32,6 +36,8 @@ enum GenerationError: Error, CustomStringConvertible {
       return "Unknown value for generation parameter '\(name)': '\(value)'"
     case let .wrappedError(message, error):
       return "\(message): \(error)"
+    case let .unsupportedParameter(name, message):
+      return "Unsupported parameter '\(name)': \(message)"
     }
   }
 }
@@ -42,36 +48,14 @@ enum FileNaming: String {
   case dropPath = "DropPath"
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 struct GeneratorOptions {
-  enum Visibility: String {
-    case `internal` = "Internal"
-    case `public` = "Public"
-    case `package` = "Package"
-
-    var sourceSnippet: String {
-      switch self {
-      case .internal:
-        return "internal"
-      case .public:
-        return "public"
-      case .package:
-        return "package"
-      }
-    }
-  }
-
-  private(set) var visibility = Visibility.internal
-
-  private(set) var generateServer = true
-  private(set) var generateClient = true
-
   private(set) var protoToModuleMappings = ProtoFileToModuleMappings()
   private(set) var fileNaming = FileNaming.fullPath
   private(set) var extraModuleImports: [String] = []
-  private(set) var gRPCModuleName = "GRPC"
+  private(set) var availabilityOverrides: [(os: String, version: String)] = []
-  private(set) var swiftProtobufModuleName = "SwiftProtobuf"
+
-  private(set) var generateReflectionData = false
+  private(set) var config: ProtobufCodeGenerator.Config = .defaults
-  private(set) var useAccessLevelOnImports = false
 
   init(parameter: any CodeGeneratorParameter) throws {
     try self.init(pairs: parameter.parsedPairs)
@@ -81,22 +65,22 @@ struct GeneratorOptions {
     for pair in pairs {
       switch pair.key {
       case "Visibility":
-        if let value = Visibility(rawValue: pair.value) {
+        if let value = GRPCCodeGen.CodeGenerator.Config.AccessLevel(protocOption: pair.value) {
-          self.visibility = value
+          self.config.accessLevel = value
         } else {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
 
       case "Server":
         if let value = Bool(pair.value.lowercased()) {
-          self.generateServer = value
+          self.config.generateServer = value
         } else {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
 
       case "Client":
         if let value = Bool(pair.value.lowercased()) {
-          self.generateClient = value
+          self.config.generateClient = value
         } else {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
@@ -129,28 +113,49 @@ struct GeneratorOptions {
 
       case "GRPCModuleName":
         if !pair.value.isEmpty {
-          self.gRPCModuleName = pair.value
+          self.config.moduleNames.grpcCore = pair.value
+        } else {
+          throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
+        }
+
+      case "GRPCProtobufModuleName":
+        if !pair.value.isEmpty {
+          self.config.moduleNames.grpcProtobuf = pair.value
         } else {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
 
       case "SwiftProtobufModuleName":
         if !pair.value.isEmpty {
-          self.swiftProtobufModuleName = pair.value
+          self.config.moduleNames.swiftProtobuf = pair.value
+        } else {
+          throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
+        }
+
+      case "Availability":
+        if !pair.value.isEmpty {
+          let parts = pair.value.split(separator: " ", maxSplits: 1)
+          if parts.count == 2 {
+            self.availabilityOverrides.append((os: String(parts[0]), version: String(parts[1])))
+          } else {
+            throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
+          }
         } else {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
 
       case "ReflectionData":
-        if let value = Bool(pair.value.lowercased()) {
+        throw GenerationError.unsupportedParameter(
-          self.generateReflectionData = value
+          name: pair.key,
-        } else {
+          message: """
-          throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
+            The reflection service uses descriptor sets. Refer to the protoc docs and the \
-        }
+            '--descriptor_set_out' option for more information.
+            """
+        )
 
       case "UseAccessLevelOnImports":
         if let value = Bool(pair.value.lowercased()) {
-          self.useAccessLevelOnImports = value
+          self.config.accessLevelOnImports = value
         } else {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
@@ -187,6 +192,7 @@ struct GeneratorOptions {
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension String.SubSequence {
   func trimmingWhitespaceAndNewlines() -> String {
     let trimmedSuffix = self.drop(while: { $0.isNewline || $0.isWhitespace })
@@ -194,3 +200,19 @@ extension String.SubSequence {
     return String(trimmed)
   }
 }
+
+@available(gRPCSwiftProtobuf 2.0, *)
+extension GRPCCodeGen.CodeGenerator.Config.AccessLevel {
+  fileprivate init?(protocOption value: String) {
+    switch value {
+    case "Internal":
+      self = .internal
+    case "Public":
+      self = .public
+    case "Package":
+      self = .package
+    default:
+      return nil
+    }
+  }
+}

Sources/protoc-gen-grpc-swift-2/Version.swift

@@ -14,26 +14,17 @@
  * limitations under the License.
  */
 
+#if canImport(CGRPCProtobuf)
+private import CGRPCProtobuf
+#endif
+
 internal enum Version {
-  /// The major version.
-  internal static let major = 1
-
-  /// The minor version.
-  internal static let minor = 0
-
-  /// The patch version.
-  internal static let patch = 0
-
-  /// Any additional label.
-  internal static let label = "development"
-
   /// The version string.
   internal static var versionString: String {
-    let version = "\(Self.major).\(Self.minor).\(Self.patch)"
+    #if canImport(CGRPCProtobuf)
-    if Self.label.isEmpty {
+    String(cString: cgrprc_grpc_swift_protobuf_version())
-      return version
+    #else
-    } else {
+    "unknown"
-      return version + "-" + Self.label
+    #endif
-    }
   }
 }

Tests/GRPCProtobufCodeGenTests/ProtobufCodeGenParserTests.swift

@@ -27,25 +27,29 @@ struct ProtobufCodeGenParserTests {
     static let descriptorSetName = "test-service"
     static let fileDescriptorName = "test-service"
 
-    let codeGen: CodeGenerationRequest
+    @available(gRPCSwiftProtobuf 2.0, *)
-
+    var codeGen: CodeGenerationRequest {
-    init() throws {
+      get throws {
-      let descriptor = try #require(try Self.fileDescriptor)
+        let descriptor = try Self.fileDescriptor
-      self.codeGen = try parseDescriptor(descriptor)
+        return try parseDescriptor(descriptor)
+      }
     }
 
     @Test("Filename")
-    func fileName() {
+    @available(gRPCSwiftProtobuf 2.0, *)
-      #expect(self.codeGen.fileName == "test-service.proto")
+    func fileName() throws {
+      #expect(try self.codeGen.fileName == "test-service.proto")
     }
 
     @Test("Leading trivia")
-    func leadingTrivia() {
+    @available(gRPCSwiftProtobuf 2.0, *)
+    func leadingTrivia() throws {
       let expected = """
         /// Leading trivia.
 
         // DO NOT EDIT.
         // swift-format-ignore-file
+        // swiftlint:disable all
         //
         // Generated by the gRPC Swift generator plugin for the protocol buffer compiler.
         // Source: test-service.proto
@@ -55,94 +59,112 @@ struct ProtobufCodeGenParserTests {
 
         """
 
-      #expect(self.codeGen.leadingTrivia == expected)
+      #expect(try self.codeGen.leadingTrivia == expected)
     }
 
     @Test("Dependencies")
-    func dependencies() {
+    @available(gRPCSwiftProtobuf 2.0, *)
+    func dependencies() throws {
       let expected: [GRPCCodeGen.Dependency] = [
-        .init(module: "GRPCProtobuf", accessLevel: .internal)  // Always an internal import
+        .init(module: "GRPCProtobuf", accessLevel: .internal),  // Always an internal import
+        .init(module: "SwiftProtobuf", accessLevel: .internal),
       ]
-      #expect(self.codeGen.dependencies == expected)
+      #expect(try self.codeGen.dependencies == expected)
     }
 
     @Suite("Service")
     struct Service {
-      let service: GRPCCodeGen.ServiceDescriptor
+      @available(gRPCSwiftProtobuf 2.0, *)
-
+      var service: GRPCCodeGen.ServiceDescriptor {
-      init() throws {
+        get throws {
-        let request = try parseDescriptor(try #require(try TestService.fileDescriptor))
+          let request = try parseDescriptor(try TestService.fileDescriptor)
-        try #require(request.services.count == 1)
+          try #require(request.services.count == 1)
-        self.service = try #require(request.services.first)
+          return try #require(request.services.first)
+        }
       }
 
       @Test("Name")
-      func name() {
+      @available(gRPCSwiftProtobuf 2.0, *)
-        #expect(self.service.name.identifyingName == "test.TestService")
+      func name() throws {
+        #expect(try self.service.name.identifyingName == "test.TestService")
       }
 
       @Suite("Methods")
       struct Methods {
-        let unary: GRPCCodeGen.MethodDescriptor
+        @available(gRPCSwiftProtobuf 2.0, *)
-        let clientStreaming: GRPCCodeGen.MethodDescriptor
+        var service: GRPCCodeGen.ServiceDescriptor {
-        let serverStreaming: GRPCCodeGen.MethodDescriptor
+          get throws {
-        let bidiStreaming: GRPCCodeGen.MethodDescriptor
+            let request = try parseDescriptor(try TestService.fileDescriptor)
+            try #require(request.services.count == 1)
+            return try #require(request.services.first)
+          }
+        }
 
-        init() throws {
+        @available(gRPCSwiftProtobuf 2.0, *)
-          let request = try parseDescriptor(try #require(try TestService.fileDescriptor))
+        var unary: GRPCCodeGen.MethodDescriptor {
-          #expect(request.services.count == 1)
+          get throws { try self.service.methods[0] }
-          let service = try #require(request.services.first)
+        }
-
+        @available(gRPCSwiftProtobuf 2.0, *)
-          self.unary = service.methods[0]
+        var clientStreaming: GRPCCodeGen.MethodDescriptor {
-          self.clientStreaming = service.methods[1]
+          get throws { try self.service.methods[1] }
-          self.serverStreaming = service.methods[2]
+        }
-          self.bidiStreaming = service.methods[3]
+        @available(gRPCSwiftProtobuf 2.0, *)
+        var serverStreaming: GRPCCodeGen.MethodDescriptor {
+          get throws { try self.service.methods[2] }
+        }
+        @available(gRPCSwiftProtobuf 2.0, *)
+        var bidiStreaming: GRPCCodeGen.MethodDescriptor {
+          get throws { try self.service.methods[3] }
         }
 
         @Test("Documentation")
-        func documentation() {
+        @available(gRPCSwiftProtobuf 2.0, *)
-          #expect(self.unary.documentation == "/// Unary docs.\n")
+        func documentation() throws {
-          #expect(self.clientStreaming.documentation == "/// Client streaming docs.\n")
+          #expect(try self.unary.documentation == "/// Unary docs.\n")
-          #expect(self.serverStreaming.documentation == "/// Server streaming docs.\n")
+          #expect(try self.clientStreaming.documentation == "/// Client streaming docs.\n")
-          #expect(self.bidiStreaming.documentation == "/// Bidirectional streaming docs.\n")
+          #expect(try self.serverStreaming.documentation == "/// Server streaming docs.\n")
+          #expect(try self.bidiStreaming.documentation == "/// Bidirectional streaming docs.\n")
         }
 
         @Test("Name")
-        func name() {
+        @available(gRPCSwiftProtobuf 2.0, *)
-          #expect(self.unary.name.identifyingName == "Unary")
+        func name() throws {
-          #expect(self.clientStreaming.name.identifyingName == "ClientStreaming")
+          try #expect(self.unary.name.identifyingName == "Unary")
-          #expect(self.serverStreaming.name.identifyingName == "ServerStreaming")
+          try #expect(self.clientStreaming.name.identifyingName == "ClientStreaming")
-          #expect(self.bidiStreaming.name.identifyingName == "BidirectionalStreaming")
+          try #expect(self.serverStreaming.name.identifyingName == "ServerStreaming")
+          try #expect(self.bidiStreaming.name.identifyingName == "BidirectionalStreaming")
         }
 
         @Test("Input")
-        func input() {
+        @available(gRPCSwiftProtobuf 2.0, *)
-          #expect(self.unary.inputType == "Test_TestInput")
+        func input() throws {
-          #expect(!self.unary.isInputStreaming)
+          #expect(try self.unary.inputType == "Test_TestInput")
+          #expect(try !self.unary.isInputStreaming)
 
-          #expect(self.clientStreaming.inputType == "Test_TestInput")
+          #expect(try self.clientStreaming.inputType == "Test_TestInput")
-          #expect(self.clientStreaming.isInputStreaming)
+          #expect(try self.clientStreaming.isInputStreaming)
 
-          #expect(self.serverStreaming.inputType == "Test_TestInput")
+          #expect(try self.serverStreaming.inputType == "Test_TestInput")
-          #expect(!self.serverStreaming.isInputStreaming)
+          #expect(try !self.serverStreaming.isInputStreaming)
 
-          #expect(self.bidiStreaming.inputType == "Test_TestInput")
+          #expect(try self.bidiStreaming.inputType == "Test_TestInput")
-          #expect(self.bidiStreaming.isInputStreaming)
+          #expect(try self.bidiStreaming.isInputStreaming)
         }
 
         @Test("Output")
-        func output() {
+        @available(gRPCSwiftProtobuf 2.0, *)
-          #expect(self.unary.outputType == "Test_TestOutput")
+        func output() throws {
-          #expect(!self.unary.isOutputStreaming)
+          #expect(try self.unary.outputType == "Test_TestOutput")
+          #expect(try !self.unary.isOutputStreaming)
 
-          #expect(self.clientStreaming.outputType == "Test_TestOutput")
+          #expect(try self.clientStreaming.outputType == "Test_TestOutput")
-          #expect(!self.clientStreaming.isOutputStreaming)
+          #expect(try !self.clientStreaming.isOutputStreaming)
 
-          #expect(self.serverStreaming.outputType == "Test_TestOutput")
+          #expect(try self.serverStreaming.outputType == "Test_TestOutput")
-          #expect(self.serverStreaming.isOutputStreaming)
+          #expect(try self.serverStreaming.isOutputStreaming)
 
-          #expect(self.bidiStreaming.outputType == "Test_TestOutput")
+          #expect(try self.bidiStreaming.outputType == "Test_TestOutput")
-          #expect(self.bidiStreaming.isOutputStreaming)
+          #expect(try self.bidiStreaming.isOutputStreaming)
         }
       }
     }
@@ -153,51 +175,58 @@ struct ProtobufCodeGenParserTests {
     static let descriptorSetName = "foo-service"
     static let fileDescriptorName = "foo-service"
 
-    let codeGen: CodeGenerationRequest
+    @available(gRPCSwiftProtobuf 2.0, *)
-
+    var codeGen: CodeGenerationRequest {
-    init() throws {
+      get throws {
-      let descriptor = try #require(try Self.fileDescriptor)
+        let descriptor = try Self.fileDescriptor
-      self.codeGen = try parseDescriptor(descriptor)
+        return try parseDescriptor(descriptor)
+      }
     }
 
     @Test("Name")
-    func name() {
+    @available(gRPCSwiftProtobuf 2.0, *)
-      #expect(self.codeGen.fileName == "foo-service.proto")
+    func name() throws {
+      #expect(try self.codeGen.fileName == "foo-service.proto")
     }
 
     @Test("Dependencies")
-    func dependencies() {
+    @available(gRPCSwiftProtobuf 2.0, *)
+    func dependencies() throws {
       let expected: [GRPCCodeGen.Dependency] = [
         .init(module: "GRPCProtobuf", accessLevel: .internal)  // Always an internal import
       ]
-      #expect(self.codeGen.dependencies == expected)
+      #expect(try self.codeGen.dependencies == expected)
     }
 
     @Test("Service1")
+    @available(gRPCSwiftProtobuf 2.0, *)
     func service1() throws {
-      let service = self.codeGen.services[0]
+      let service = try self.codeGen.services[0]
       #expect(service.name.identifyingName == "foo.FooService1")
       #expect(service.methods.count == 1)
     }
 
     @Test("Service1.Method")
+    @available(gRPCSwiftProtobuf 2.0, *)
     func service1Method() throws {
-      let method = self.codeGen.services[0].methods[0]
+      let method = try self.codeGen.services[0].methods[0]
       #expect(method.name.identifyingName == "Foo")
       #expect(method.inputType == "Foo_FooInput")
       #expect(method.outputType == "Foo_FooOutput")
     }
 
     @Test("Service2")
+    @available(gRPCSwiftProtobuf 2.0, *)
     func service2() throws {
-      let service = self.codeGen.services[1]
+      let service = try self.codeGen.services[1]
       #expect(service.name.identifyingName == "foo.FooService2")
       #expect(service.methods.count == 1)
     }
 
     @Test("Service2.Method")
+    @available(gRPCSwiftProtobuf 2.0, *)
     func service2Method() throws {
-      let method = self.codeGen.services[1].methods[0]
+      let method = try self.codeGen.services[1].methods[0]
       #expect(method.name.identifyingName == "Foo")
       #expect(method.inputType == "Foo_FooInput")
       #expect(method.outputType == "Foo_FooOutput")
@@ -209,18 +238,14 @@ struct ProtobufCodeGenParserTests {
     static var descriptorSetName: String { "bar-service" }
     static var fileDescriptorName: String { "bar-service" }
 
-    let codeGen: CodeGenerationRequest
-    let service: GRPCCodeGen.ServiceDescriptor
-
-    init() throws {
-      let descriptor = try #require(try Self.fileDescriptor)
-      self.codeGen = try parseDescriptor(descriptor)
-      self.service = try #require(self.codeGen.services.first)
-    }
-
     @Test("Service name")
-    func serviceName() {
+    @available(gRPCSwiftProtobuf 2.0, *)
-      #expect(self.service.name.identifyingName == "BarService")
+    func serviceName() throws {
+      let descriptor = try Self.fileDescriptor
+      let codeGen = try parseDescriptor(descriptor)
+      let service = try #require(codeGen.services.first)
+
+      #expect(service.name.identifyingName == "BarService")
     }
   }
 
@@ -229,20 +254,17 @@ struct ProtobufCodeGenParserTests {
     static let descriptorSetName = "wkt-service"
     static let fileDescriptorName = "wkt-service"
 
-    let codeGen: CodeGenerationRequest
-
-    init() throws {
-      let descriptor = try #require(try Self.fileDescriptor)
-      self.codeGen = try parseDescriptor(descriptor)
-    }
-
     @Test("Dependencies")
-    func dependencies() {
+    @available(gRPCSwiftProtobuf 2.0, *)
+    func dependencies() throws {
+      let descriptor = try Self.fileDescriptor
+      let codeGen = try parseDescriptor(descriptor)
+
       let expected: [Dependency] = [
         Dependency(module: "GRPCProtobuf", accessLevel: .internal),
         Dependency(module: "SwiftProtobuf", accessLevel: .internal),
       ]
-      #expect(self.codeGen.dependencies == expected)
+      #expect(codeGen.dependencies == expected)
     }
   }
 }

Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift

@@ -25,17 +25,43 @@ struct ProtobufCodeGeneratorTests {
     static let descriptorSetName = "test-service"
     static let fileDescriptorName = "test-service"
 
-    @Test("Generate", arguments: [CodeGenerator.Config.AccessLevel.internal])
+    enum Availability {
-    func generate(accessLevel: GRPCCodeGen.CodeGenerator.Config.AccessLevel) throws {
+      case `default`
-      let generator = ProtobufCodeGenerator(
+      case fooOS
-        config: CodeGenerator.Config(
+
-          accessLevel: accessLevel,
+      var override: [(String, String)] {
-          accessLevelOnImports: false,
+        switch self {
-          client: true,
+        case .default:
-          server: true,
+          return []
-          indentation: 2
+        case .fooOS:
-        )
+          return [("fooOS", "42.0")]
-      )
+        }
+      }
+
+      var expected: String {
+        switch self {
+        case .default:
+          return "macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0"
+        case .fooOS:
+          return "fooOS 42.0"
+        }
+      }
+    }
+
+    @available(gRPCSwiftProtobuf 2.0, *)
+    @Test(
+      "Generate",
+      arguments: [CodeGenerator.Config.AccessLevel.internal],
+      [Availability.default, Availability.fooOS]
+    )
+    func generate(
+      accessLevel: GRPCCodeGen.CodeGenerator.Config.AccessLevel,
+      availability: Availability
+    ) throws {
+      var config = ProtobufCodeGenerator.Config.defaults
+      config.accessLevel = accessLevel
+      config.indentation = 2
+      let generator = ProtobufCodeGenerator(config: config)
 
       let access: String
       switch accessLevel {
@@ -49,10 +75,13 @@ struct ProtobufCodeGeneratorTests {
         fatalError()
       }
 
+      let expectedAvailability = availability.expected
+
       let generated = try generator.generateCode(
         fileDescriptor: Self.fileDescriptor,
         protoFileModuleMappings: ProtoFileToModuleMappings(),
-        extraModuleImports: []
+        extraModuleImports: [],
+        availabilityOverrides: availability.override
       )
 
       let expected = """
@@ -60,6 +89,7 @@ struct ProtobufCodeGeneratorTests {
 
         // DO NOT EDIT.
         // swift-format-ignore-file
+        // swiftlint:disable all
         //
         // Generated by the gRPC Swift generator plugin for the protocol buffer compiler.
         // Source: test-service.proto
@@ -69,10 +99,12 @@ struct ProtobufCodeGeneratorTests {
 
         import GRPCCore
         import GRPCProtobuf
+        import SwiftProtobuf
 
         // MARK: - test.TestService
 
         /// Namespace containing generated types for the "test.TestService" service.
+        @available(\(expectedAvailability), *)
         \(access) enum Test_TestService {
           /// Service descriptor for the "test.TestService" service.
           \(access) static let descriptor = GRPCCore.ServiceDescriptor(fullyQualifiedService: "test.TestService")
@@ -136,6 +168,7 @@ struct ProtobufCodeGeneratorTests {
           }
         }
 
+        @available(\(expectedAvailability), *)
         extension GRPCCore.ServiceDescriptor {
           /// Service descriptor for the "test.TestService" service.
           \(access) static let test_TestService = GRPCCore.ServiceDescriptor(fullyQualifiedService: "test.TestService")
@@ -143,6 +176,7 @@ struct ProtobufCodeGeneratorTests {
 
         // MARK: test.TestService (server)
 
+        @available(\(expectedAvailability), *)
         extension Test_TestService {
           /// Streaming variant of the service protocol for the "test.TestService" service.
           ///
@@ -404,6 +438,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Default implementation of 'registerMethods(with:)'.
+        @available(\(expectedAvailability), *)
         extension Test_TestService.StreamingServiceProtocol {
           \(access) func registerMethods<Transport>(with router: inout GRPCCore.RPCRouter<Transport>) where Transport: GRPCCore.ServerTransport {
             router.registerHandler(
@@ -454,6 +489,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Default implementation of streaming methods from 'StreamingServiceProtocol'.
+        @available(\(expectedAvailability), *)
         extension Test_TestService.ServiceProtocol {
           \(access) func unary(
             request: GRPCCore.StreamingServerRequest<Test_TestInput>,
@@ -490,6 +526,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Default implementation of methods from 'ServiceProtocol'.
+        @available(\(expectedAvailability), *)
         extension Test_TestService.SimpleServiceProtocol {
           \(access) func unary(
             request: GRPCCore.ServerRequest<Test_TestInput>,
@@ -554,6 +591,7 @@ struct ProtobufCodeGeneratorTests {
 
         // MARK: test.TestService (client)
 
+        @available(\(expectedAvailability), *)
         extension Test_TestService {
           /// Generated client protocol for the "test.TestService" service.
           ///
@@ -812,6 +850,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Helpers providing default arguments to 'ClientProtocol' methods.
+        @available(\(expectedAvailability), *)
         extension Test_TestService.ClientProtocol {
           /// Call the "Unary" method.
           ///
@@ -927,6 +966,7 @@ struct ProtobufCodeGeneratorTests {
         }
 
         // Helpers providing sugared APIs for 'ClientProtocol' methods.
+        @available(\(expectedAvailability), *)
         extension Test_TestService.ClientProtocol {
           /// Call the "Unary" method.
           ///
@@ -1062,6 +1102,36 @@ struct ProtobufCodeGeneratorTests {
 
       #expect(generated == expected)
     }
+
+    @Test("Generate with different module names")
+    @available(gRPCSwiftProtobuf 2.0, *)
+    func generateWithDifferentModuleNames() throws {
+      var config = ProtobufCodeGenerator.Config.defaults
+      let defaultNames = config.moduleNames
+
+      config.accessLevel = .public
+      config.indentation = 2
+      config.moduleNames.grpcCore = String(config.moduleNames.grpcCore.reversed())
+      config.moduleNames.grpcProtobuf = String(config.moduleNames.grpcProtobuf.reversed())
+      config.moduleNames.swiftProtobuf = String(config.moduleNames.swiftProtobuf.reversed())
+
+      let generator = ProtobufCodeGenerator(config: config)
+      let generated = try generator.generateCode(
+        fileDescriptor: Self.fileDescriptor,
+        protoFileModuleMappings: ProtoFileToModuleMappings(),
+        extraModuleImports: []
+      )
+
+      // Mustn't contain the default names.
+      #expect(!generated.contains(defaultNames.grpcCore))
+      #expect(!generated.contains(defaultNames.grpcProtobuf))
+      #expect(!generated.contains(defaultNames.swiftProtobuf))
+
+      // Must contain the configured names.
+      #expect(generated.contains(config.moduleNames.grpcCore))
+      #expect(generated.contains(config.moduleNames.grpcProtobuf))
+      #expect(generated.contains(config.moduleNames.swiftProtobuf))
+    }
   }
 
   @Suite("File-without-services (foo-messages.proto)")
@@ -1070,16 +1140,13 @@ struct ProtobufCodeGeneratorTests {
     static let fileDescriptorName = "foo-messages"
 
     @Test("Generate")
+    @available(gRPCSwiftProtobuf 2.0, *)
     func generate() throws {
-      let generator = ProtobufCodeGenerator(
+      var config: ProtobufCodeGenerator.Config = .defaults
-        config: CodeGenerator.Config(
+      config.accessLevel = .public
-          accessLevel: .public,
+      config.indentation = 2
-          accessLevelOnImports: false,
+
-          client: true,
+      let generator = ProtobufCodeGenerator(config: config)
-          server: true,
-          indentation: 2
-        )
-      )
 
       let generated = try generator.generateCode(
         fileDescriptor: Self.fileDescriptor,
@@ -1092,6 +1159,7 @@ struct ProtobufCodeGeneratorTests {
 
         // DO NOT EDIT.
         // swift-format-ignore-file
+        // swiftlint:disable all
         //
         // Generated by the gRPC Swift generator plugin for the protocol buffer compiler.
         // Source: foo-messages.proto

Tests/GRPCProtobufCodeGenTests/Utilities.swift

@@ -63,11 +63,12 @@ private func loadDescriptorSet(
   )
 
   let url = try #require(maybeURL)
-  let data = try #require(try Data(contentsOf: url))
+  let data = try Data(contentsOf: url)
   let descriptorSet = try Google_Protobuf_FileDescriptorSet(serializedBytes: data)
   return DescriptorSet(proto: descriptorSet)
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 func parseDescriptor(
   _ descriptor: FileDescriptor,
   extraModuleImports: [String] = [],
@@ -76,7 +77,8 @@ func parseDescriptor(
   let parser = ProtobufCodeGenParser(
     protoFileModuleMappings: .init(),
     extraModuleImports: extraModuleImports,
-    accessLevel: accessLevel
+    accessLevel: accessLevel,
+    moduleNames: .defaults
   )
   return try parser.parse(descriptor: descriptor)
 }

Tests/GRPCProtobufTests/Errors/DetailedErrorTests.swift

@@ -40,6 +40,7 @@ struct DetailedErrorTests {
       (["Help", "Help", "Help"], [.help(.testValue), .help(.testValue), .help(.testValue)]),
     ] as [([String], [ErrorDetails])]
   )
+  @available(gRPCSwiftProtobuf 2.0, *)
   func rpcStatus(details: [String], expected: [ErrorDetails]) async throws {
     let inProcess = InProcessTransport()
     try await withGRPCServer(transport: inProcess.server, services: [ErrorThrowingService()]) { _ in
@@ -95,11 +96,27 @@ struct DetailedErrorTests {
       (.localizedMessage(.testValue), #"LocalizedMessage(locale: "l", message: "m")"#),
     ] as [(ErrorDetails, String)]
   )
+  @available(gRPCSwiftProtobuf 2.0, *)
   func errorInfoDescription(_ details: ErrorDetails, expected: String) {
     #expect(String(describing: details) == expected)
   }
+
+  @Test("Round-trip encoding of GoogleRPCStatus")
+  @available(gRPCSwiftProtobuf 2.0, *)
+  func googleRPCStatusRoundTripCoding() throws {
+    let detail = ErrorDetails.BadRequest(violations: [.init(field: "foo", description: "bar")])
+    let status = GoogleRPCStatus(code: .dataLoss, message: "Uh oh", details: [.badRequest(detail)])
+
+    let serialized: [UInt8] = try status.serializedBytes()
+    let deserialized = try GoogleRPCStatus(serializedBytes: serialized)
+    #expect(deserialized.code == status.code)
+    #expect(deserialized.message == status.message)
+    #expect(deserialized.details.count == status.details.count)
+    #expect(deserialized.details.first?.badRequest == detail)
+  }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 private struct ErrorThrowingService: ErrorService.SimpleServiceProtocol {
   func throwError(
     request: ThrowInput,
@@ -170,14 +187,17 @@ private struct ErrorThrowingService: ErrorService.SimpleServiceProtocol {
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.ErrorInfo {
   fileprivate static let testValue = Self(reason: "r", domain: "d", metadata: ["k": "v"])
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.RetryInfo {
   fileprivate static let testValue = Self(delay: .seconds(1))
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.DebugInfo {
   fileprivate static let testValue = Self(
     stack: ["foo.foo()", "foo.bar()"],
@@ -185,6 +205,7 @@ extension ErrorDetails.DebugInfo {
   )
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.QuotaFailure {
   fileprivate static let testValue = Self(
     violations: [
@@ -193,6 +214,7 @@ extension ErrorDetails.QuotaFailure {
   )
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.PreconditionFailure {
   fileprivate static let testValue = Self(
     violations: [
@@ -201,6 +223,7 @@ extension ErrorDetails.PreconditionFailure {
   )
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.BadRequest {
   fileprivate static let testValue = Self(
     violations: [
@@ -209,14 +232,17 @@ extension ErrorDetails.BadRequest {
   )
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.RequestInfo {
   fileprivate static let testValue = Self(requestID: "id", servingData: "d")
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.ResourceInfo {
   fileprivate static let testValue = Self(type: "t", name: "n", errorDescription: "d")
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.Help {
   fileprivate static let testValue = Self(
     links: [
@@ -225,6 +251,7 @@ extension ErrorDetails.Help {
   )
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorDetails.LocalizedMessage {
   fileprivate static let testValue = Self(locale: "l", message: "m")
 }

Tests/GRPCProtobufTests/Errors/Generated/error-service.grpc.swift

@@ -15,6 +15,7 @@
 
 // DO NOT EDIT.
 // swift-format-ignore-file
+// swiftlint:disable all
 //
 // Generated by the gRPC Swift generator plugin for the protocol buffer compiler.
 // Source: error-service.proto
@@ -29,6 +30,7 @@ internal import SwiftProtobuf
 // MARK: - ErrorService
 
 /// Namespace containing generated types for the "ErrorService" service.
+@available(gRPCSwiftProtobuf 2.0, *)
 internal enum ErrorService {
     /// Service descriptor for the "ErrorService" service.
     internal static let descriptor = GRPCCore.ServiceDescriptor(fullyQualifiedService: "ErrorService")
@@ -53,6 +55,7 @@ internal enum ErrorService {
     }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension GRPCCore.ServiceDescriptor {
     /// Service descriptor for the "ErrorService" service.
     internal static let ErrorService = GRPCCore.ServiceDescriptor(fullyQualifiedService: "ErrorService")
@@ -60,6 +63,7 @@ extension GRPCCore.ServiceDescriptor {
 
 // MARK: ErrorService (server)
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorService {
     /// Streaming variant of the service protocol for the "ErrorService" service.
     ///
@@ -133,6 +137,7 @@ extension ErrorService {
 }
 
 // Default implementation of 'registerMethods(with:)'.
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorService.StreamingServiceProtocol {
     internal func registerMethods<Transport>(with router: inout GRPCCore.RPCRouter<Transport>) where Transport: GRPCCore.ServerTransport {
         router.registerHandler(
@@ -150,6 +155,7 @@ extension ErrorService.StreamingServiceProtocol {
 }
 
 // Default implementation of streaming methods from 'StreamingServiceProtocol'.
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorService.ServiceProtocol {
     internal func throwError(
         request: GRPCCore.StreamingServerRequest<ThrowInput>,
@@ -164,6 +170,7 @@ extension ErrorService.ServiceProtocol {
 }
 
 // Default implementation of methods from 'ServiceProtocol'.
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorService.SimpleServiceProtocol {
     internal func throwError(
         request: GRPCCore.ServerRequest<ThrowInput>,
@@ -181,6 +188,7 @@ extension ErrorService.SimpleServiceProtocol {
 
 // MARK: ErrorService (client)
 
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorService {
     /// Generated client protocol for the "ErrorService" service.
     ///
@@ -256,6 +264,7 @@ extension ErrorService {
 }
 
 // Helpers providing default arguments to 'ClientProtocol' methods.
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorService.ClientProtocol {
     /// Call the "ThrowError" method.
     ///
@@ -284,6 +293,7 @@ extension ErrorService.ClientProtocol {
 }
 
 // Helpers providing sugared APIs for 'ClientProtocol' methods.
+@available(gRPCSwiftProtobuf 2.0, *)
 extension ErrorService.ClientProtocol {
     /// Call the "ThrowError" method.
     ///

Tests/GRPCProtobufTests/ProtobufCodingTests.swift

@@ -19,6 +19,7 @@ import GRPCProtobuf
 import SwiftProtobuf
 import XCTest
 
+@available(gRPCSwiftProtobuf 2.0, *)
 final class ProtobufCodingTests: XCTestCase {
   func testSerializeDeserializeRoundtrip() throws {
     let message = Google_Protobuf_Timestamp.with {
@@ -73,6 +74,7 @@ final class ProtobufCodingTests: XCTestCase {
   }
 }
 
+@available(gRPCSwiftProtobuf 2.0, *)
 struct TestMessage: SwiftProtobuf.Message {
   var text: String = ""
   var unknownFields = SwiftProtobuf.UnknownStorage()

dev/protos/generate.sh

@@ -21,12 +21,12 @@ protoc=$(which protoc)
 
 # Checkout and build the plugins.
 swift build --package-path "$root" --product protoc-gen-swift
-swift build --package-path "$root" --product protoc-gen-grpc-swift
+swift build --package-path "$root" --product protoc-gen-grpc-swift-2
 
 # Grab the plugin paths.
 bin_path=$(swift build --package-path "$root" --show-bin-path)
 protoc_gen_swift="$bin_path/protoc-gen-swift"
-protoc_gen_grpc_swift="$bin_path/protoc-gen-grpc-swift"
+protoc_gen_grpc_swift="$bin_path/protoc-gen-grpc-swift-2"
 
 # Generates gRPC by invoking protoc with the gRPC Swift plugin.
 # Parameters:
@@ -36,10 +36,10 @@ protoc_gen_grpc_swift="$bin_path/protoc-gen-grpc-swift"
 # - $4 onwards: options to forward to the plugin
 function generate_grpc {
   local proto=$1
-  local args=("--plugin=$protoc_gen_grpc_swift" "--proto_path=${2}" "--grpc-swift_out=${3}")
+  local args=("--plugin=$protoc_gen_grpc_swift" "--proto_path=${2}" "--grpc-swift-2_out=${3}")
 
   for option in "${@:4}"; do
-    args+=("--grpc-swift_opt=$option")
+    args+=("--grpc-swift-2_opt=$option")
   done
 
   invoke_protoc "${args[@]}" "$proto"
@@ -94,7 +94,7 @@ function generate_error_service {
   output="$root/Tests/GRPCProtobufTests/Errors/Generated"
 
   generate_message "$proto" "$(dirname "$proto")" "$output" "Visibility=Internal" "UseAccessLevelOnImports=true"
-  generate_grpc "$proto" "$(dirname "$proto")" "$output" "Visibility=Internal" "UseAccessLevelOnImports=true"
+  generate_grpc "$proto" "$(dirname "$proto")" "$output" "Visibility=Internal" "UseAccessLevelOnImports=true" "Availability=gRPCSwiftProtobuf 2.0"
 }
 
 #- DESCRIPTOR SETS ------------------------------------------------------------
@@ -105,7 +105,9 @@ function generate_test_service_descriptor_set {
   proto_path="$(dirname "$proto")"
   output="$root/Tests/GRPCProtobufCodeGenTests/Generated/test-service.pb"
 
-  invoke_protoc --descriptor_set_out="$output" "$proto" -I "$proto_path" --include_source_info
+  invoke_protoc --descriptor_set_out="$output" "$proto" -I "$proto_path" \
+    --include_imports \
+    --include_source_info
 }
 
 function generate_foo_service_descriptor_set {

dev/protos/local/test-service.proto

@@ -3,6 +3,9 @@ syntax = "proto3";
 
 package test;
 
+// Using a WKT forces an "SwiftProtobuf" to be imported in generated code.
+import "google/protobuf/any.proto";
+
 // Service docs.
 service TestService {
   // Unary docs.
@@ -15,5 +18,8 @@ service TestService {
   rpc BidirectionalStreaming (stream TestInput) returns (stream TestOutput) {}
 }
 
-message TestInput {}
+message TestInput {
+  google.protobuf.Any any = 1;
+}
+
 message TestOutput {}

dev/setup-plugin-tests.sh

@@ -24,73 +24,185 @@ output_directory="${PLUGIN_TESTS_OUTPUT_DIRECTORY:=$(mktemp -d)}"
 here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 grpc_swift_protobuf_directory="$(readlink -f "${here}/..")"
 resources_directory="$(readlink -f "${grpc_swift_protobuf_directory}/IntegrationTests/PluginTests/Resources")"
+config="${resources_directory}/Config"
+sources="${resources_directory}/Sources"
+protos="${resources_directory}/Protos"
 scratch_directory="$(mktemp -d)"
+package_manifest="${scratch_directory}/Package.swift"
 
 echo "Output directory: $output_directory"
 echo "grpc-swift-protobuf directory: $grpc_swift_protobuf_directory"
 
 # modify Package.swift
-cp "${resources_directory}/Package.swift" "${scratch_directory}/"
+cp "${resources_directory}/Sources/Package.swift" "${scratch_directory}/"
-cat >> "${scratch_directory}/Package.swift" <<- EOM
+cat >> "${package_manifest}" <<- EOM
 package.dependencies.append(
   .package(path: "$grpc_swift_protobuf_directory")
 )
 EOM
 
-# test_01_top_level_config_file
+function test_dir_name {
-test_01_output_directory="${output_directory}/test_01_top_level_config_file"
+  # $FUNCNAME is a stack of function names. The 0th element is the name of this
-mkdir -p "${test_01_output_directory}/Sources/Protos"
+  # function, so the 1st element is the calling function.
-cp "${scratch_directory}/Package.swift" "${test_01_output_directory}/"
+  echo "${output_directory}/${FUNCNAME[1]}"
-cp "${resources_directory}/HelloWorldAdopter.swift" "${test_01_output_directory}/Sources/adopter.swift"
+}
-cp "${resources_directory}/HelloWorld/HelloWorld.proto" "${test_01_output_directory}/Sources/Protos"
-cp "${resources_directory}/internal-grpc-swift-proto-generator-config.json" "${test_01_output_directory}/Sources/grpc-swift-proto-generator-config.json"
 
-# test_02_peer_config_file
+function test_01_top_level_config_file {
-test_02_output_directory="${output_directory}/test_02_peer_config_file"
+  # .
-mkdir -p "${test_02_output_directory}/Sources/Protos"
+  # ├── Package.swift
-cp "${scratch_directory}/Package.swift" "${test_02_output_directory}/"
+  # └── Sources
-cp "${resources_directory}/HelloWorldAdopter.swift" "${test_02_output_directory}/Sources/adopter.swift"
+  #     ├── HelloWorldAdopter.swift
-cp "${resources_directory}/HelloWorld/HelloWorld.proto" "${test_02_output_directory}/Sources/Protos/"
+  #     ├── Protos
-cp "${resources_directory}/internal-grpc-swift-proto-generator-config.json" "${test_02_output_directory}/Sources/Protos/grpc-swift-proto-generator-config.json"
+  #     │   └── HelloWorld.proto
+  #     └── grpc-swift-proto-generator-config.json
 
-# test_03_separate_service_message_protos
+  local -r test_dir=$(test_dir_name)
-test_03_output_directory="${output_directory}/test_03_separate_service_message_protos"
+  mkdir -p "${test_dir}/Sources/Protos"
-mkdir -p "${test_03_output_directory}/Sources/Protos"
+  cp "${package_manifest}" "${test_dir}/"
-cp "${scratch_directory}/Package.swift" "${test_03_output_directory}/"
+  cp "${sources}/HelloWorldAdopter.swift" "${test_dir}/Sources/"
-cp "${resources_directory}/HelloWorldAdopter.swift" "${test_03_output_directory}/Sources/adopter.swift"
+  cp "${protos}/HelloWorld/HelloWorld.proto" "${test_dir}/Sources/Protos"
-cp "${resources_directory}/internal-grpc-swift-proto-generator-config.json" "${test_03_output_directory}/Sources/Protos/grpc-swift-proto-generator-config.json"
+  cp "${config}/internal-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/grpc-swift-proto-generator-config.json"
-cp "${resources_directory}/HelloWorld/Service.proto"  "${test_03_output_directory}/Sources/Protos/"
+}
-cp "${resources_directory}/HelloWorld/Messages.proto"  "${test_03_output_directory}/Sources/Protos/"
 
-# test_04_cross_directory_imports
+function test_02_peer_config_file {
-test_04_output_directory="${output_directory}/test_04_cross_directory_imports"
+  # .
-mkdir -p "${test_04_output_directory}/Sources/Protos/directory_1"
+  # ├── Package.swift
-mkdir -p "${test_04_output_directory}/Sources/Protos/directory_2"
+  # └── Sources
-cp "${scratch_directory}/Package.swift" "${test_04_output_directory}/"
+  #     ├── HelloWorldAdopter.swift
-cp "${resources_directory}/HelloWorldAdopter.swift" "${test_04_output_directory}/Sources/adopter.swift"
+  #     └── Protos
-cp "${resources_directory}/internal-grpc-swift-proto-generator-config.json" "${test_04_output_directory}/Sources/Protos/directory_1/grpc-swift-proto-generator-config.json"
+  #         ├── HelloWorld.proto
-cp "${resources_directory}/import-directory-1-grpc-swift-proto-generator-config.json" "${test_04_output_directory}/Sources/Protos/directory_2/grpc-swift-proto-generator-config.json"
+  #         └── grpc-swift-proto-generator-config.json
-cp "${resources_directory}/HelloWorld/Service.proto" "${test_04_output_directory}/Sources/Protos/directory_2/"
-cp "${resources_directory}/HelloWorld/Messages.proto" "${test_04_output_directory}/Sources/Protos/directory_1/"
 
-# test_05_two_definitions
+  local -r test_dir=$(test_dir_name)
-test_05_output_directory="${output_directory}/test_05_two_definitions"
+  mkdir -p "${test_dir}/Sources/Protos"
-mkdir -p "${test_05_output_directory}/Sources/Protos/HelloWorld"
+  cp "${package_manifest}" "${test_dir}/"
-mkdir -p "${test_05_output_directory}/Sources/Protos/Foo"
+  cp "${sources}/HelloWorldAdopter.swift" "${test_dir}/Sources/"
-cp "${scratch_directory}/Package.swift" "${test_05_output_directory}/"
+  cp "${protos}/HelloWorld/HelloWorld.proto" "${test_dir}/Sources/Protos/"
-cp "${resources_directory}/FooHelloWorldAdopter.swift" "${test_05_output_directory}/Sources/adopter.swift"
+  cp "${config}/internal-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/grpc-swift-proto-generator-config.json"
-cp "${resources_directory}/HelloWorld/HelloWorld.proto" "${test_05_output_directory}/Sources/Protos/HelloWorld/"
+}
-cp "${resources_directory}/internal-grpc-swift-proto-generator-config.json" "${test_05_output_directory}/Sources/Protos/grpc-swift-proto-generator-config.json"
-cp "${resources_directory}/Foo/foo-messages.proto" "${test_05_output_directory}/Sources/Protos/Foo/"
-cp "${resources_directory}/Foo/foo-service.proto" "${test_05_output_directory}/Sources/Protos/Foo/"
 
-# test_06_nested_definitions
+function test_03_separate_service_message_protos {
-test_06_output_directory="${output_directory}/test_06_nested_definitions"
+  # .
-mkdir -p "${test_06_output_directory}/Sources/Protos/HelloWorld/FooDefinitions/Foo"
+  # ├── Package.swift
-cp "${scratch_directory}/Package.swift" "${test_06_output_directory}/"
+  # └── Sources
-cp "${resources_directory}/FooHelloWorldAdopter.swift" "${test_06_output_directory}/Sources/adopter.swift"
+  #     ├── HelloWorldAdopter.swift
-cp "${resources_directory}/HelloWorld/HelloWorld.proto" "${test_06_output_directory}/Sources/Protos/HelloWorld/"
+  #     └── Protos
-cp "${resources_directory}/internal-grpc-swift-proto-generator-config.json" "${test_06_output_directory}/Sources/Protos/HelloWorld/grpc-swift-proto-generator-config.json"
+  #         ├── Messages.proto
-cp "${resources_directory}/public-grpc-swift-proto-generator-config.json" "${test_06_output_directory}/Sources/Protos/HelloWorld/FooDefinitions/grpc-swift-proto-generator-config.json"
+  #         ├── Service.proto
-cp "${resources_directory}/Foo/foo-messages.proto" "${test_06_output_directory}/Sources/Protos/HelloWorld/FooDefinitions/Foo/"
+  #         └── grpc-swift-proto-generator-config.json
-cp "${resources_directory}/Foo/foo-service.proto" "${test_06_output_directory}/Sources/Protos/HelloWorld/FooDefinitions/Foo/"
+
+  local -r test_dir=$(test_dir_name)
+  mkdir -p "${test_dir}/Sources/Protos"
+  cp "${package_manifest}" "${test_dir}/"
+  cp "${sources}/HelloWorldAdopter.swift" "${test_dir}/Sources/"
+  cp "${config}/internal-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/grpc-swift-proto-generator-config.json"
+  cp "${protos}/HelloWorld/Service.proto"  "${test_dir}/Sources/Protos/"
+  cp "${protos}/HelloWorld/Messages.proto"  "${test_dir}/Sources/Protos/"
+}
+
+function test_04_cross_directory_imports {
+  # .
+  # ├── Package.swift
+  # └── Sources
+  #     ├── HelloWorldAdopter.swift
+  #     └── Protos
+  #         ├── directory_1
+  #         │   ├── Messages.proto
+  #         │   └── grpc-swift-proto-generator-config.json
+  #         └── directory_2
+  #             ├── Service.proto
+  #             └── grpc-swift-proto-generator-config.json
+
+  local -r test_dir=$(test_dir_name)
+  mkdir -p "${test_dir}/Sources/Protos/directory_1"
+  mkdir -p "${test_dir}/Sources/Protos/directory_2"
+
+  cp "${package_manifest}" "${test_dir}/"
+  cp "${sources}/HelloWorldAdopter.swift" "${test_dir}/Sources/"
+  cp "${config}/internal-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/directory_1/grpc-swift-proto-generator-config.json"
+  cp "${config}/import-directory-1-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/directory_2/grpc-swift-proto-generator-config.json"
+  cp "${protos}/HelloWorld/Service.proto" "${test_dir}/Sources/Protos/directory_2/"
+  cp "${protos}/HelloWorld/Messages.proto" "${test_dir}/Sources/Protos/directory_1/"
+}
+
+function test_05_two_definitions {
+  # .
+  # ├── Package.swift
+  # └── Sources
+  #     ├── FooHelloWorldAdopter.swift
+  #     └── Protos
+  #         ├── Foo
+  #         │   ├── foo-messages.proto
+  #         │   └── foo-service.proto
+  #         ├── HelloWorld
+  #         │   └── HelloWorld.proto
+  #         └── grpc-swift-proto-generator-config.json
+
+  local -r test_dir=$(test_dir_name)
+  mkdir -p "${test_dir}/Sources/Protos/HelloWorld"
+  mkdir -p "${test_dir}/Sources/Protos/Foo"
+
+  cp "${package_manifest}" "${test_dir}/"
+  cp "${sources}/FooHelloWorldAdopter.swift" "${test_dir}/Sources/"
+  cp "${protos}/HelloWorld/HelloWorld.proto" "${test_dir}/Sources/Protos/HelloWorld/"
+  cp "${config}/internal-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/grpc-swift-proto-generator-config.json"
+  cp "${protos}/Foo/foo-messages.proto" "${test_dir}/Sources/Protos/Foo/"
+  cp "${protos}/Foo/foo-service.proto" "${test_dir}/Sources/Protos/Foo/"
+}
+
+function test_06_nested_definitions {
+  # .
+  # ├── Package.swift
+  # └── Sources
+  #     ├── FooHelloWorldAdopter.swift
+  #     └── Protos
+  #         └── HelloWorld
+  #             ├── FooDefinitions
+  #             │   ├── Foo
+  #             │   │   ├── foo-messages.proto
+  #             │   │   └── foo-service.proto
+  #             │   └── grpc-swift-proto-generator-config.json
+  #             ├── HelloWorld.proto
+  #             └── grpc-swift-proto-generator-config.json
+
+  local -r test_dir=$(test_dir_name)
+  mkdir -p "${test_dir}/Sources/Protos/HelloWorld/FooDefinitions/Foo"
+  cp "${package_manifest}" "${test_dir}/"
+  cp "${sources}/FooHelloWorldAdopter.swift" "${test_dir}/Sources/"
+  cp "${protos}/HelloWorld/HelloWorld.proto" "${test_dir}/Sources/Protos/HelloWorld/"
+  cp "${config}/internal-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/HelloWorld/grpc-swift-proto-generator-config.json"
+  cp "${config}/public-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/HelloWorld/FooDefinitions/grpc-swift-proto-generator-config.json"
+  cp "${protos}/Foo/foo-messages.proto" "${test_dir}/Sources/Protos/HelloWorld/FooDefinitions/Foo/"
+  cp "${protos}/Foo/foo-service.proto" "${test_dir}/Sources/Protos/HelloWorld/FooDefinitions/Foo/"
+}
+
+function test_07_duplicated_proto_file_name {
+  # .
+  # ├── Package.swift
+  # └── Sources
+  #     ├── NoOp.swift
+  #     └── Protos
+  #         ├── grpc-swift-proto-generator-config.json
+  #         ├── noop
+  #         │   └── noop.proto
+  #         └── noop2
+  #             └── noop.proto
+
+  local -r test_dir=$(test_dir_name)
+  mkdir -p "${test_dir}/Sources/Protos"
+
+  cp "${package_manifest}" "${test_dir}/"
+  mkdir -p "${test_dir}/Sources/Protos"
+  cp -rp "${protos}/noop" "${test_dir}/Sources/Protos"
+  cp -rp "${protos}/noop2" "${test_dir}/Sources/Protos"
+  cp "${sources}/NoOp.swift" "${test_dir}/Sources"
+  cp "${config}/internal-grpc-swift-proto-generator-config.json" "${test_dir}/Sources/Protos/grpc-swift-proto-generator-config.json"
+}
+
+test_01_top_level_config_file
+test_02_peer_config_file
+test_03_separate_service_message_protos
+test_04_cross_directory_imports
+test_05_two_definitions
+test_06_nested_definitions
+test_07_duplicated_proto_file_name