Add compatibility checks

Signed-off-by: Jon Skeet <jonskeet@google.com>

.github/workflows/build.yml

@@ -32,3 +32,5 @@ jobs:
       run: |
         dotnet build
         dotnet test
+        # Pack production packages to validate compatibility
+        dotnet pack -p:ContinuousIntegrationBuild=true

RELEASING.md

@@ -24,6 +24,8 @@ The normal steps are expected to be:
 - The maintainer who creates and merges this change is also (by default) responsible for manually creating
   the GitHub release and (automatically) a corresponding tag. See below for the format of these.
 - NuGet packages are automatically created and pushed when the release is created.
+- After a minor or major release, the `PackageValidationBaselineVersion` is updated
+  to the new version number as the baseline for a future release to be compatible with.
 
 ## Stable package versioning
 

src/Directory.Build.props

@@ -2,9 +2,10 @@
   <PropertyGroup>
     <!-- 
       - We use the same version number for all stable
-      - packages. See PROCESSES.md for details.
+      - packages. See RELEASING.md for details.
       -->
     <Version>2.7.1</Version>
+    <PackageValidationBaselineVersion>2.7.0</PackageValidationBaselineVersion>
     
     <!-- Make the repository root available for other properties -->
     <RepoRoot>$([System.IO.Path]::GetDirectoryName($([MSBuild]::GetPathOfFileAbove('.gitignore', '$(MSBuildThisFileDirectory)'))))</RepoRoot>
@@ -15,6 +16,8 @@
     <Deterministic>True</Deterministic>
     <TreatWarningsAsErrors>True</TreatWarningsAsErrors>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>    
+    <EnablePackageValidation>true</EnablePackageValidation>
+    <ApiCompatEnableRuleCannotChangeParameterName>true</ApiCompatEnableRuleCannotChangeParameterName>
     
     <!-- Package properties -->
     <AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>