Enable and fix pedantic v1.9 lints (#445)

Co-authored-by: Vyacheslav Egorov <vegorov@google.com>

.github/workflows/dart.yml

@@ -28,18 +28,17 @@ jobs:
         run: dart pub get
       - name: Check formatting
         run: dart format --output=none --set-exit-if-changed .
-      - name: Analyze code (lib and test)
-        run: dart analyze --fatal-infos .
       - name: Analyze code (introp and examples)
         run: |
           for example in interop example/*/; do
             pushd $example
-            echo [Analyzing $example]
+            echo [Getting dependencies in $example]
             dart pub get
-            dart analyze --fatal-infos .
             popd
           done
         shell: bash
+      - name: Analyze code
+        run: dart analyze --fatal-infos .
 
   # Run tests on a matrix consisting of three dimensions:
   # 1. OS: mac, windows, linux

analysis_options.yaml

@@ -1,21 +1,56 @@
 # Lint rules and documentation, see http://dart-lang.github.io/linter/lints
-analyzer:
+
-  exclude:
-  - example/**
-  - interop/**
 linter:
   rules:
+    - always_declare_return_types
+    - always_require_non_null_named_parameters
+    - annotate_overrides
+    - avoid_empty_else
     - avoid_init_to_null
+    - avoid_null_checks_in_equality_operators
+    - avoid_relative_lib_imports
+    - avoid_return_types_on_setters
+    - avoid_shadowing_type_parameters
+    - avoid_types_as_parameter_names
+    - camel_case_extensions
     - cancel_subscriptions
     - close_sinks
+    - curly_braces_in_flow_control_structures
     - directives_ordering
+    - empty_catches
+    - empty_constructor_bodies
     - hash_and_equals
     - iterable_contains_unrelated_type
+    - library_names
+    - library_prefixes
     - list_remove_unrelated_type
+    - no_duplicate_case_values
+    - null_closures
+    - omit_local_variable_types
+    - prefer_adjacent_string_concatenation
+    - prefer_collection_literals
+    - prefer_conditional_assignment
+    - prefer_contains
+    - prefer_equal_for_default_values
     - prefer_final_fields
     - prefer_final_locals
+    - prefer_for_elements_to_map_fromIterable
+    - prefer_generic_function_type_aliases
+    - prefer_if_null_operators
+    - prefer_is_empty
     - prefer_is_not_empty
+    - prefer_iterable_whereType
+    - prefer_single_quotes
+    - prefer_spread_collections
+    - recursive_getters
+    - slash_for_doc_comments
     - test_types_in_equals
+    - type_init_formals
+    - unnecessary_const
+    - unnecessary_new
+    - unnecessary_null_in_if_null_operators
+    - unnecessary_this
     - unrelated_type_equality_checks
+    - use_function_type_syntax_for_parameters
+    - use_rethrow_when_possible
     - valid_regexps
-    - prefer_collection_literals

example/grpc-web/lib/app.dart

@@ -33,11 +33,11 @@ class EchoApp {
   }
 
   void _addLeftMessage(String message) {
-    _addMessage(message, "label-primary pull-left");
+    _addMessage(message, 'label-primary pull-left');
   }
 
   void _addRightMessage(String message) {
-    _addMessage(message, "label-default pull-right");
+    _addMessage(message, 'label-default pull-right');
   }
 
   void _addMessage(String message, String cssClass) {

example/metadata/bin/client.dart

@@ -15,6 +15,6 @@
 
 import 'package:metadata/src/client.dart';
 
-main(List<String> args) {
+void main(List<String> args) {
   Client().main(args);
 }

example/metadata/bin/server.dart

@@ -15,6 +15,6 @@
 
 import 'package:metadata/src/server.dart';
 
-main(List<String> args) {
+void main(List<String> args) {
   Server().main(args);
 }

example/metadata/lib/src/client.dart

@@ -113,7 +113,7 @@ class Client {
   /// after receiving more than 5 responses.
   Future<void> runFibonacciCancel() async {
     final call = stub.fibonacci(Empty());
-    int count = 0;
+    var count = 0;
     try {
       await for (var number in call) {
         count++;
@@ -135,7 +135,7 @@ class Client {
   Future<void> runFibonacciTimeout() async {
     final call = stub.fibonacci(Empty(),
         options: CallOptions(timeout: Duration(seconds: 2)));
-    int count = 0;
+    var count = 0;
     try {
       await for (var number in call) {
         count++;

example/metadata/lib/src/server.dart

@@ -40,7 +40,7 @@ class MetadataService extends MetadataServiceBase {
 
   @override
   Stream<Number> addOne(grpc.ServiceCall call, Stream<Number> request) async* {
-    int lastNumber = -1;
+    var lastNumber = -1;
     try {
       await for (var number in request) {
         lastNumber = number.value;
@@ -56,9 +56,10 @@ class MetadataService extends MetadataServiceBase {
   }
 
   /// Streams a Fibonacci number every 500ms until the call is canceled.
+  @override
   Stream<Number> fibonacci(grpc.ServiceCall call, Empty request) async* {
-    int previous = 0;
+    var previous = 0;
-    int current = 1;
+    var current = 1;
     try {
       while (true) {
         await Future.delayed(Duration(milliseconds: 500));

example/route_guide/bin/client.dart

@@ -15,6 +15,6 @@
 
 import 'package:route_guide/src/client.dart';
 
-main(List<String> args) async {
+Future<void> main(List<String> args) async {
   await Client().main(args);
 }

example/route_guide/bin/server.dart

@@ -15,6 +15,6 @@
 
 import 'package:route_guide/src/server.dart';
 
-main(List<String> args) async {
+Future<void> main(List<String> args) async {
   await Server().main(args);
 }

example/route_guide/lib/src/client.dart

@@ -94,7 +94,7 @@ class Client {
     Stream<Point> generateRoute(int count) async* {
       final random = Random();
 
-      for (int i = 0; i < count; i++) {
+      for (var i = 0; i < count; i++) {
         final point = featuresDb[random.nextInt(featuresDb.length)].location;
         print(
             'Visiting point ${point.latitude / coordFactor}, ${point.longitude / coordFactor}');

example/route_guide/lib/src/server.dart

@@ -75,9 +75,9 @@ class RouteGuideService extends RouteGuideServiceBase {
   @override
   Future<RouteSummary> recordRoute(
       grpc.ServiceCall call, Stream<Point> request) async {
-    int pointCount = 0;
+    var pointCount = 0;
-    int featureCount = 0;
+    var featureCount = 0;
-    double distance = 0.0;
+    var distance = 0.0;
     Point previous;
     final timer = Stopwatch();
 
@@ -110,7 +110,9 @@ class RouteGuideService extends RouteGuideServiceBase {
       grpc.ServiceCall call, Stream<RouteNote> request) async* {
     await for (var note in request) {
       final notes = routeNotes.putIfAbsent(note.location, () => <RouteNote>[]);
-      for (var note in notes) yield note;
+      for (var note in notes) {
+        yield note;
+      }
       notes.add(note);
     }
   }

interop/lib/src/client.dart

@@ -51,7 +51,7 @@ class Tester {
     return File(serviceAccountKeyFile).readAsStringSync();
   }
 
-  void set serverPort(String value) {
+  set serverPort(String value) {
     if (value == null) {
       _serverPort = null;
       return;
@@ -63,11 +63,11 @@ class Tester {
     }
   }
 
-  void set useTls(String value) {
+  set useTls(String value) {
     _useTls = value != 'false';
   }
 
-  void set useTestCA(String value) {
+  set useTestCA(String value) {
     _useTestCA = value == 'true';
   }
 
@@ -613,7 +613,7 @@ class Tester {
     final call = client.fullDuplexCall(requests.stream);
     requests.close();
     final responses = await call.toList();
-    if (responses.length != 0) {
+    if (responses.isNotEmpty) {
       throw 'Received too many responses. ${responses.length} != 0';
     }
   }

lib/src/auth/auth.dart

@@ -60,6 +60,7 @@ abstract class BaseAuthenticator {
 abstract class HttpBasedAuthenticator extends BaseAuthenticator {
   Future<void>? _call;
 
+  @override
   Future<void> obtainAccessCredentials(String uri) {
     if (_call == null) {
       final authClient = http.Client();
@@ -94,6 +95,7 @@ class JwtServiceAccountAuthenticator extends BaseAuthenticator {
 
   String? get projectId => _projectId;
 
+  @override
   Future<void> obtainAccessCredentials(String uri) async {
     _accessToken = _jwtTokenFor(_serviceAccountCredentials, _keyId, uri);
   }

lib/src/auth/auth_io.dart

@@ -7,6 +7,7 @@ import 'package:http/http.dart' as http;
 import 'auth.dart';
 
 class ComputeEngineAuthenticator extends HttpBasedAuthenticator {
+  @override
   Future<auth.AccessCredentials> obtainCredentialsWithClient(
           http.Client client, String uri) =>
       auth.obtainAccessCredentialsViaMetadataServer(client);
@@ -30,6 +31,7 @@ class ServiceAccountAuthenticator extends HttpBasedAuthenticator {
 
   String? get projectId => _projectId;
 
+  @override
   Future<auth.AccessCredentials> obtainCredentialsWithClient(
           http.Client client, String uri) =>
       auth.obtainAccessCredentialsViaServiceAccount(
@@ -47,6 +49,7 @@ class _CredentialsRefreshingAuthenticator extends HttpBasedAuthenticator {
     this._quotaProject,
   );
 
+  @override
   Future<void> authenticate(Map<String, String> metadata, String uri) async {
     await super.authenticate(metadata, uri);
     if (_quotaProject != null) {

lib/src/auth/rsa.dart

@@ -30,7 +30,7 @@ class RS256Signer {
   // NIST sha-256 OID (2 16 840 1 101 3 4 2 1)
   // See a reference for the encoding here:
   // http://msdn.microsoft.com/en-us/library/bb540809%28v=vs.85%29.aspx
-  static const _RSA_SHA256_ALGORITHM_IDENTIFIER = const [
+  static const _RSA_SHA256_ALGORITHM_IDENTIFIER = [
     0x06,
     0x09,
     0x60,
@@ -52,7 +52,7 @@ class RS256Signer {
     final digest = _digestInfo(sha256.convert(bytes).bytes);
     final modulusLen = (_rsaKey.bitLength + 7) ~/ 8;
 
-    final block = new Uint8List(modulusLen);
+    final block = Uint8List(modulusLen);
     final padLength = block.length - digest.length - 3;
     block[0] = 0x00;
     block[1] = 0x01;
@@ -68,7 +68,7 @@ class RS256Signer {
     //     digest OCTET STRING
     // }
     var offset = 0;
-    final digestInfo = new Uint8List(
+    final digestInfo = Uint8List(
         2 + 2 + _RSA_SHA256_ALGORITHM_IDENTIFIER.length + 2 + 2 + hash.length);
     {
       // DigestInfo
@@ -100,14 +100,14 @@ class ASN1Parser {
 
   static ASN1Object parse(Uint8List bytes) {
     Never invalidFormat(String msg) {
-      throw new ArgumentError("Invalid DER encoding: $msg");
+      throw ArgumentError('Invalid DER encoding: $msg');
     }
 
-    final data = new ByteData.view(bytes.buffer);
+    final data = ByteData.view(bytes.buffer);
-    int offset = 0;
+    var offset = 0;
     final end = bytes.length;
 
-    checkNBytesAvailable(int n) {
+    void checkNBytesAvailable(int n) {
       if ((offset + n) > end) {
         invalidFormat('Tried to read more bytes than available.');
       }
@@ -134,10 +134,10 @@ class ASN1Parser {
       // Long length encoding form:
       // This byte has in bits 0..6 the number of bytes following which encode
       // the length.
-      int countLengthBytes = lengthByte & 0x7f;
+      var countLengthBytes = lengthByte & 0x7f;
       checkNBytesAvailable(countLengthBytes);
 
-      int length = 0;
+      var length = 0;
       while (countLengthBytes > 0) {
         length = (length << 8) | data.getUint8(offset++);
         countLengthBytes--;
@@ -159,16 +159,16 @@ class ASN1Parser {
       switch (tag) {
         case INTEGER_TAG:
           final size = readEncodedLength();
-          return new ASN1Integer(RSAAlgorithm.bytes2BigInt(readBytes(size)));
+          return ASN1Integer(RSAAlgorithm.bytes2BigInt(readBytes(size)));
         case OCTET_STRING_TAG:
           final size = readEncodedLength();
-          return new ASN1OctetString(readBytes(size));
+          return ASN1OctetString(readBytes(size));
         case NULL_TAG:
           readNullBytes();
-          return new ASN1Null();
+          return ASN1Null();
         case OBJECT_ID_TAG:
           final size = readEncodedLength();
-          return new ASN1ObjectIdentifier(readBytes(size));
+          return ASN1ObjectIdentifier(readBytes(size));
         case SEQUENCE_TAG:
           final lengthInBytes = readEncodedLength();
           if ((offset + lengthInBytes) > end) {
@@ -180,7 +180,7 @@ class ASN1Parser {
           while (offset < endOfSequence) {
             objects.add(decodeObject());
           }
-          return new ASN1Sequence(objects);
+          return ASN1Sequence(objects);
         default:
           invalidFormat(
               'Unexpected tag $tag at offset ${offset - 1} (end: $end).');
@@ -189,7 +189,7 @@ class ASN1Parser {
 
     final obj = decodeObject();
     if (offset != bytes.length) {
-      throw new ArgumentError('More bytes than expected in ASN1 encoding.');
+      throw ArgumentError('More bytes than expected in ASN1 encoding.');
     }
     return obj;
   }
@@ -300,17 +300,17 @@ abstract class RSAAlgorithm {
   static BigInt bytes2BigInt(List<int> bytes) {
     var number = BigInt.zero;
     for (var i = 0; i < bytes.length; i++) {
-      number = (number << 8) | new BigInt.from(bytes[i]);
+      number = (number << 8) | BigInt.from(bytes[i]);
     }
     return number;
   }
 
   static List<int> integer2Bytes(BigInt integer, int intendedLength) {
     if (integer < BigInt.one) {
-      throw new ArgumentError('Only positive integers are supported.');
+      throw ArgumentError('Only positive integers are supported.');
     }
-    final bytes = new Uint8List(intendedLength);
+    final bytes = Uint8List(intendedLength);
-    for (int i = bytes.length - 1; i >= 0; i--) {
+    for (var i = bytes.length - 1; i >= 0; i--) {
       bytes[i] = (integer & _bigIntFF).toInt();
       integer >>= 8;
     }
@@ -318,4 +318,4 @@ abstract class RSAAlgorithm {
   }
 }
 
-final _bigIntFF = new BigInt.from(0xff);
+final _bigIntFF = BigInt.from(0xff);

lib/src/client/call.dart

@@ -50,7 +50,7 @@ const _statusDetailsHeader = 'grpc-status-details-bin';
 /// by previous metadata providers) and the [uri] that is being called, and is
 /// expected to modify the map before returning or before completing the
 /// returned [Future].
-typedef FutureOr<void> MetadataProvider(
+typedef MetadataProvider = FutureOr<void> Function(
     Map<String, String> metadata, String uri);
 
 /// Runtime options for an RPC.

lib/src/client/client.dart

@@ -45,8 +45,7 @@ regenerate these stubs using  protobuf compiler plugin version 19.2.0 or newer.
 
   ResponseFuture<R> $createUnaryCall<Q, R>(ClientMethod<Q, R> method, Q request,
       {CallOptions? options}) {
-    ClientUnaryInvoker<Q, R> invoker = (method, request, options) =>
+    var invoker = (method, request, options) => ResponseFuture<R>(
-        ResponseFuture<R>(
         _channel.createCall<Q, R>(method, Stream.value(request), options));
 
     for (final interceptor in _interceptors.reversed) {
@@ -61,7 +60,7 @@ regenerate these stubs using  protobuf compiler plugin version 19.2.0 or newer.
   ResponseStream<R> $createStreamingCall<Q, R>(
       ClientMethod<Q, R> method, Stream<Q> requests,
       {CallOptions? options}) {
-    ClientStreamingInvoker<Q, R> invoker = (method, request, options) =>
+    var invoker = (method, request, options) =>
         ResponseStream<R>(_channel.createCall<Q, R>(method, requests, options));
 
     for (final interceptor in _interceptors.reversed) {

lib/src/client/common.dart

@@ -44,6 +44,7 @@ abstract class Response {
 /// A gRPC response producing a single value.
 class ResponseFuture<R> extends DelegatingFuture<R>
     with _ResponseMixin<dynamic, R> {
+  @override
   final ClientCall<dynamic, R> _call;
 
   static R _ensureOnlyOneResponse<R>(R? previous, R element) {
@@ -67,11 +68,13 @@ class ResponseFuture<R> extends DelegatingFuture<R>
 /// A gRPC response producing a stream of values.
 class ResponseStream<R> extends DelegatingStream<R>
     with _ResponseMixin<dynamic, R> {
+  @override
   final ClientCall<dynamic, R> _call;
 
   ResponseStream(this._call) : super(_call.response);
 
-  ResponseFuture<R> get single => ResponseFuture(this._call);
+  @override
+  ResponseFuture<R> get single => ResponseFuture(_call);
 }
 
 abstract class _ResponseMixin<Q, R> implements Response {

lib/src/client/http2_connection.dart

@@ -66,13 +66,15 @@ class Http2ClientConnection implements connection.ClientConnection {
 
   ChannelCredentials get credentials => options.credentials;
 
+  @override
   String get authority => _transportConnector.authority;
 
+  @override
   String get scheme => options.credentials.isSecure ? 'https' : 'http';
 
   ConnectionState get state => _state;
 
-  static const _estimatedRoundTripTime = const Duration(milliseconds: 20);
+  static const _estimatedRoundTripTime = Duration(milliseconds: 20);
 
   Future<ClientTransportConnection> connectTransport() async {
     final connection = await _transportConnector.connect();
@@ -81,7 +83,7 @@ class Http2ClientConnection implements connection.ClientConnection {
     // Give the settings settings-frame a bit of time to arrive.
     // TODO(sigurdm): This is a hack. The http2 package should expose a way of
     // waiting for the settings frame to arrive.
-    await new Future.delayed(_estimatedRoundTripTime);
+    await Future.delayed(_estimatedRoundTripTime);
 
     if (_state == ConnectionState.shutdown) {
       _transportConnector.shutdown();
@@ -119,8 +121,8 @@ class Http2ClientConnection implements connection.ClientConnection {
   ///
   /// Assumes [_transportConnection] is not `null`.
   void _refreshConnectionIfUnhealthy() {
-    final bool isHealthy = _transportConnection!.isOpen;
+    final isHealthy = _transportConnection!.isOpen;
-    final bool shouldRefresh =
+    final shouldRefresh =
         _connectionLifeTimer.elapsed > options.connectionTimeout;
     if (shouldRefresh) {
       _transportConnection!.finish();
@@ -130,6 +132,7 @@ class Http2ClientConnection implements connection.ClientConnection {
     }
   }
 
+  @override
   void dispatchCall(ClientCall call) {
     if (_transportConnection != null) {
       _refreshConnectionIfUnhealthy();
@@ -149,6 +152,7 @@ class Http2ClientConnection implements connection.ClientConnection {
     }
   }
 
+  @override
   GrpcTransportStream makeRequest(String path, Duration? timeout,
       Map<String, String> metadata, ErrorHandler onRequestFailure,
       {CallOptions? callOptions}) {
@@ -188,12 +192,14 @@ class Http2ClientConnection implements connection.ClientConnection {
     _failCall(call, 'Connection shutting down.');
   }
 
+  @override
   Future<void> shutdown() async {
     if (_state == ConnectionState.shutdown) return null;
     _setShutdownState();
     await _transportConnection?.finish();
   }
 
+  @override
   Future<void> terminate() async {
     _setShutdownState();
     await _transportConnection?.terminate();
@@ -353,7 +359,7 @@ class _SocketTransportConnector implements ClientTransportConnector {
     final host =
         _host is String ? _host as String : (_host as InternetAddress).host;
     return _options.credentials.authority ??
-        (_port == 443 ? host : "$host:$_port");
+        (_port == 443 ? host : '$host:$_port');
   }
 
   @override

lib/src/client/options.dart

@@ -26,7 +26,7 @@ const defaultIdleTimeout = Duration(minutes: 5);
 const defaultConnectionTimeOut = Duration(minutes: 50);
 const defaultUserAgent = 'dart-grpc/2.0.0';
 
-typedef Duration BackoffStrategy(Duration? lastBackoff);
+typedef BackoffStrategy = Duration Function(Duration? lastBackoff);
 
 // Backoff algorithm from https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
 const _initialBackoff = Duration(seconds: 1);

lib/src/client/transport/http2_credentials.dart

@@ -21,7 +21,8 @@ import '../../shared/security.dart';
 /// returns `true`, the bad certificate is allowed, and the TLS handshake can
 /// continue. If the handler returns `false`, the TLS handshake fails, and the
 /// connection is aborted.
-typedef bool BadCertificateHandler(X509Certificate certificate, String host);
+typedef BadCertificateHandler = bool Function(
+    X509Certificate certificate, String host);
 
 /// Bad certificate handler that disables all certificate checks.
 /// DO NOT USE IN PRODUCTION!
@@ -60,7 +61,7 @@ class ChannelCredentials {
         ..setTrustedCertificatesBytes(_certificateBytes!,
             password: _certificatePassword);
     }
-    final context = new SecurityContext(withTrustedRoots: true);
+    final context = SecurityContext(withTrustedRoots: true);
     context.setAlpnProtocols(supportedAlpnProtocols, false);
     return context;
   }

lib/src/client/transport/http2_transport.dart

@@ -25,10 +25,12 @@ import 'transport.dart';
 
 class Http2TransportStream extends GrpcTransportStream {
   final TransportStream _transportStream;
+  @override
   final Stream<GrpcMessage> incomingMessages;
   final StreamController<List<int>> _outgoingMessages = StreamController();
   final ErrorHandler _onError;
 
+  @override
   StreamSink<List<int>> get outgoingMessages => _outgoingMessages.sink;
 
   Http2TransportStream(

lib/src/client/transport/transport.dart

@@ -17,12 +17,13 @@ import 'dart:async';
 
 import '../../shared/message.dart';
 
-typedef void SocketClosedHandler();
+typedef SocketClosedHandler = void Function();
-typedef void ActiveStateHandler(bool isActive);
+typedef ActiveStateHandler = void Function(bool isActive);
-typedef void ErrorHandler(error, StackTrace stackTrace);
+typedef ErrorHandler = void Function(Object, StackTrace);
 
 abstract class GrpcTransportStream {
   Stream<GrpcMessage> get incomingMessages;
+
   StreamSink<List<int>> get outgoingMessages;
 
   Future<void> terminate();

lib/src/client/transport/xhr_transport.dart

@@ -166,7 +166,9 @@ class XhrClientConnection extends ClientConnection {
 
   XhrClientConnection(this.uri);
 
+  @override
   String get authority => uri.authority;
+  @override
   String get scheme => uri.scheme;
 
   void _initializeRequest(HttpRequest request, Map<String, String> metadata) {
@@ -198,7 +200,7 @@ class XhrClientConnection extends ClientConnection {
       requestUri = cors.moveHttpHeadersToQueryParam(metadata, requestUri);
     }
 
-    final HttpRequest request = createHttpRequest();
+    final request = createHttpRequest();
     request.open('POST', requestUri.toString());
     if (callOptions is WebCallOptions && callOptions.withCredentials == true) {
       request.withCredentials = true;
@@ -206,7 +208,7 @@ class XhrClientConnection extends ClientConnection {
     // Must set headers after calling open().
     _initializeRequest(request, metadata);
 
-    final XhrTransportStream transportStream =
+    final transportStream =
         XhrTransportStream(request, onError: onError, onDone: _removeStream);
     _requests.add(transportStream);
     return transportStream;

lib/src/server/handler.dart

@@ -66,16 +66,22 @@ class ServerHandler_ extends ServiceCall {
     this._codecRegistry,
   );
 
+  @override
   DateTime? get deadline => _deadline;
 
+  @override
   bool get isCanceled => _isCanceled;
 
+  @override
   bool get isTimedOut => _isTimedOut;
 
+  @override
   Map<String, String>? get clientMetadata => _clientMetadata;
 
+  @override
   Map<String, String>? get headers => _customHeaders;
 
+  @override
   Map<String, String>? get trailers => _customTrailers;
 
   void handle() {
@@ -162,7 +168,7 @@ class ServerHandler_ extends ServiceCall {
   Future<GrpcError?> _applyInterceptors() async {
     try {
       for (final interceptor in _interceptors) {
-        final error = await interceptor(this, this._descriptor);
+        final error = await interceptor(this, _descriptor);
         if (error != null) {
           return error;
         }
@@ -293,6 +299,7 @@ class ServerHandler_ extends ServiceCall {
     }
   }
 
+  @override
   void sendHeaders() {
     if (_headersSent) throw GrpcError.internal('Headers already sent');
 
@@ -316,6 +323,7 @@ class ServerHandler_ extends ServiceCall {
     _headersSent = true;
   }
 
+  @override
   void sendTrailers({int? status = 0, String? message}) {
     _timeoutTimer?.cancel();
 
@@ -336,7 +344,7 @@ class ServerHandler_ extends ServiceCall {
     outgoingTrailersMap['grpc-status'] = status.toString();
     if (message != null) {
       outgoingTrailersMap['grpc-message'] =
-          Uri.encodeFull(message).replaceAll("%20", " ");
+          Uri.encodeFull(message).replaceAll('%20', ' ');
     }
 
     final outgoingTrailers = <Header>[];

lib/src/server/server.dart

@@ -61,6 +61,7 @@ class ServerTlsCredentials extends ServerCredentials {
       this.privateKey,
       this.privateKeyPassword});
 
+  @override
   SecurityContext get securityContext {
     final context = createSecurityContext(true);
     if (privateKey != null) {
@@ -152,6 +153,7 @@ class Server extends ConnectionServer {
     return null;
   }
 
+  @override
   Service? lookupService(String service) => _services[service];
 
   /// Starts the [Server] with the given options.
@@ -162,9 +164,9 @@ class Server extends ConnectionServer {
       int? port,
       ServerCredentials? security,
       ServerSettings? http2ServerSettings,
-      int backlog: 0,
+      int backlog = 0,
-      bool v6Only: false,
+      bool v6Only = false,
-      bool shared: false}) async {
+      bool shared = false}) async {
     // TODO(dart-lang/grpc-dart#9): Handle HTTP/1.1 upgrade to h2c, if allowed.
     Stream<Socket>? server;
     final securityContext = security?.securityContext;
@@ -198,6 +200,7 @@ class Server extends ConnectionServer {
     });
   }
 
+  @override
   @visibleForTesting
   ServerHandler_ serveStream_(ServerTransportStream stream) {
     return ServerHandler_(lookupService, stream, _interceptors, _codecRegistry)

lib/src/server/service.dart

@@ -84,7 +84,7 @@ class ServiceMethod<Q, R> {
     return future;
   }
 
-  void _awaitAndCatch<Q>(Future<Q> f) async {
+  void _awaitAndCatch(Future<Q> f) async {
     try {
       await f;
     } catch (_) {}

lib/src/shared/codec.dart

@@ -54,7 +54,7 @@ class GzipCodec implements Codec {
   const GzipCodec();
 
   @override
-  final encodingName = "gzip";
+  final encodingName = 'gzip';
 
   @override
   List<int> compress(List<int> data) {

lib/src/shared/profiler.dart

@@ -15,7 +15,7 @@
 
 import 'dart:developer';
 
-typedef TimelineTask TimelineTaskFactory(
+typedef TimelineTaskFactory = TimelineTask Function(
     {String? filterKey, TimelineTask? parent});
 
 TimelineTaskFactory timelineTaskFactory = _defaultTimelineTaskFactory;

test/client_handles_bad_connections_test.dart

@@ -23,6 +23,7 @@ class TestClient extends grpc.Client {
 }
 
 class TestService extends grpc.Service {
+  @override
   String get $name => 'test.TestService';
 
   TestService() {
@@ -47,11 +48,11 @@ class FixedConnectionClientChannel extends ClientChannelBase {
   ClientConnection createConnection() => clientConnection;
 }
 
-main() async {
+Future<void> main() async {
   testTcpAndUds('client reconnects after the connection gets old',
       (address) async {
     // client reconnect after a short delay.
-    final grpc.Server server = grpc.Server([TestService()]);
+    final server = grpc.Server([TestService()]);
     await server.serve(address: address, port: 0);
 
     final channel = FixedConnectionClientChannel(Http2ClientConnection(
@@ -76,7 +77,7 @@ main() async {
 
   testTcpAndUds('client reconnects when stream limit is used', (address) async {
     // client reconnect after setting stream limit.
-    final grpc.Server server = grpc.Server([TestService()]);
+    final server = grpc.Server([TestService()]);
     await server.serve(
         address: address,
         port: 0,

test/client_tests/call_test.dart

@@ -5,7 +5,7 @@ void main() {
   test('WebCallOptions mergeWith CallOptions returns WebCallOptions', () {
     final options =
         WebCallOptions(bypassCorsPreflight: true, withCredentials: true);
-    final metadata = {"test": "42"};
+    final metadata = {'test': '42'};
     final mergedOptions =
         options.mergedWith(CallOptions(metadata: metadata)) as WebCallOptions;
 

test/client_tests/client_interceptor_test.dart

@@ -13,6 +13,7 @@ class InterceptorInvocation {
 
   InterceptorInvocation(this.id, this.unary, this.streaming);
 
+  @override
   String toString() {
     return '{id: ${id}, unary: ${unary}, streaming: ${streaming}}';
   }
@@ -48,7 +49,7 @@ class FakeInterceptor implements ClientInterceptor {
 
   CallOptions _inject(CallOptions options) {
     return options.mergedWith(CallOptions(metadata: {
-      "x-interceptor": _invocations.map((i) => i.toString()).join(', '),
+      'x-interceptor': _invocations.map((i) => i.toString()).join(', '),
     }));
   }
 
@@ -57,7 +58,7 @@ class FakeInterceptor implements ClientInterceptor {
   }
 }
 
-main() {
+void main() {
   test('single unary interceptor', () async {
     final harness = ClientHarness()
       ..interceptors = [FakeInterceptor(1)]
@@ -81,7 +82,7 @@ main() {
       expectedResult: responseValue,
       expectedPath: '/Test/Unary',
       expectedCustomHeaders: {
-        "x-interceptor": "{id: 1, unary: 1, streaming: 0}"
+        'x-interceptor': '{id: 1, unary: 1, streaming: 0}'
       },
       serverHandlers: [handleRequest],
     );
@@ -113,8 +114,8 @@ main() {
       expectedResult: responseValue,
       expectedPath: '/Test/Unary',
       expectedCustomHeaders: {
-        "x-interceptor":
+        'x-interceptor':
-            "{id: 1, unary: 1, streaming: 0}, {id: 2, unary: 1, streaming: 0}"
+            '{id: 1, unary: 1, streaming: 0}, {id: 2, unary: 1, streaming: 0}'
       },
       serverHandlers: [handleRequest],
     );
@@ -154,7 +155,7 @@ main() {
       expectedResult: responses,
       expectedPath: '/Test/Bidirectional',
       expectedCustomHeaders: {
-        "x-interceptor": "{id: 1, unary: 0, streaming: 1}"
+        'x-interceptor': '{id: 1, unary: 0, streaming: 1}'
       },
       serverHandlers: [handleRequest, handleRequest, handleRequest],
       doneHandler: handleDone,
@@ -195,8 +196,8 @@ main() {
       expectedResult: responses,
       expectedPath: '/Test/Bidirectional',
       expectedCustomHeaders: {
-        "x-interceptor":
+        'x-interceptor':
-            "{id: 1, unary: 0, streaming: 1}, {id: 2, unary: 0, streaming: 1}"
+            '{id: 1, unary: 0, streaming: 1}, {id: 2, unary: 0, streaming: 1}'
       },
       serverHandlers: [handleRequest, handleRequest, handleRequest],
       doneHandler: handleDone,

test/client_tests/client_test.dart

@@ -330,7 +330,7 @@ void main() {
     }
 
     harness.client = TestClient(harness.channel, decode: (bytes) {
-      throw "error decoding";
+      throw 'error decoding';
     });
 
     await harness.runFailureTest(
@@ -439,9 +439,9 @@ void main() {
   });
 
   test('Default reconnect backoff backs off', () {
-    Duration lastBackoff = defaultBackoffStrategy(null);
+    var lastBackoff = defaultBackoffStrategy(null);
     expect(lastBackoff, const Duration(seconds: 1));
-    for (int i = 0; i < 12; i++) {
+    for (var i = 0; i < 12; i++) {
       final minNext = lastBackoff * (1.6 - 0.2);
       final maxNext = lastBackoff * (1.6 + 0.2);
       lastBackoff = defaultBackoffStrategy(lastBackoff);

test/client_tests/client_transport_connector_test.dart

@@ -280,7 +280,7 @@ void main() {
     }
 
     harness.client = TestClient(harness.channel, decode: (bytes) {
-      throw "error decoding";
+      throw 'error decoding';
     });
 
     await harness.runFailureTest(
@@ -389,9 +389,9 @@ void main() {
   });
 
   test('Default reconnect backoff backs off', () {
-    Duration lastBackoff = defaultBackoffStrategy(null);
+    var lastBackoff = defaultBackoffStrategy(null);
     expect(lastBackoff, const Duration(seconds: 1));
-    for (int i = 0; i < 12; i++) {
+    for (var i = 0; i < 12; i++) {
       final minNext = lastBackoff * (1.6 - 0.2);
       final maxNext = lastBackoff * (1.6 + 0.2);
       lastBackoff = defaultBackoffStrategy(lastBackoff);

test/client_tests/client_xhr_transport_test.dart

@@ -53,6 +53,7 @@ class MockHttpRequest extends Mock implements HttpRequest {
   @override
   final int status;
 
+  @override
   int get readyState => super.noSuchMethod(Invocation.getter(#readyState), -1);
 
   @override
@@ -69,7 +70,7 @@ class MockXhrClientConnection extends XhrClientConnection {
   final int _statusCode;
 
   @override
-  createHttpRequest() {
+  HttpRequest createHttpRequest() {
     final request = MockHttpRequest(code: _statusCode);
     latestRequest = request;
     return request;
@@ -360,9 +361,9 @@ void main() {
     final errorReceived = Completer<void>();
     connection.makeRequest('test_path', Duration(seconds: 10), {}, (e, _) {
       errorReceived.complete();
-      errors.add(e);
+      errors.add(e as GrpcError);
     });
-    const errorDetails = "error details";
+    const errorDetails = 'error details';
     when(connection.latestRequest.getResponseHeader('Content-Type'))
         .thenReturn('application/grpc+proto');
     when(connection.latestRequest.responseHeaders).thenReturn({});

test/connection_server_test.dart

@@ -289,7 +289,7 @@ void main() {
       }
 
       final Interceptor interceptor = (call, method) {
-        if (method.name == "Unary") {
+        if (method.name == 'Unary') {
           return null;
         }
         return GrpcError.unauthenticated('Request is unauthenticated');
@@ -311,7 +311,7 @@ void main() {
 
     group('returns error if interceptor blocks request', () {
       final Interceptor interceptor = (call, method) {
-        if (method.name == "Unary") {
+        if (method.name == 'Unary') {
           return GrpcError.unauthenticated('Request is unauthenticated');
         }
         return null;

test/grpc_web_decoding_test.dart

@@ -5,9 +5,9 @@ import 'package:grpc/src/client/transport/web_streams.dart';
 import 'package:grpc/src/shared/message.dart';
 import 'package:test/test.dart';
 
-main() {
+void main() {
-  test("decoding an empty repeated", () async {
+  test('decoding an empty repeated', () async {
-    final GrpcData data = await GrpcWebDecoder()
+    final data = await GrpcWebDecoder()
         .bind(Stream.fromIterable([
           Uint8List.fromList([0, 0, 0, 0, 0]).buffer
         ]))

test/grpc_web_server.dart

@@ -85,7 +85,7 @@ static_resources:
                     port_value: %TARGET_PORT%
 ''';
 
-hybridMain(StreamChannel channel) async {
+Future<void> hybridMain(StreamChannel channel) async {
   // Envoy output will be collected and dumped to stdout if envoy exits
   // with an error. Otherwise if verbose is specified it will be dumped
   // to stdout unconditionally.

test/grpc_web_test.dart

@@ -56,7 +56,7 @@ void main() {
 
   // Verify that terminate does not cause an exception when terminating
   // channel with multiple active requests.
-  test("terminate works", () async {
+  test('terminate works', () async {
     final channel = GrpcWebClientChannel.xhr(server.uri);
     final service = EchoServiceClient(channel);
 
@@ -96,7 +96,7 @@ void main() {
   });
 
   // Verify that stream cancellation does not cause an exception
-  test("stream cancellation works", () async {
+  test('stream cancellation works', () async {
     final channel = GrpcWebClientChannel.xhr(server.uri);
     final service = EchoServiceClient(channel);
 

test/round_trip_test.dart

@@ -23,6 +23,7 @@ class TestClient extends Client {
 }
 
 class TestService extends Service {
+  @override
   String get $name => 'test.TestService';
 
   TestService() {
@@ -43,6 +44,7 @@ class TestService extends Service {
 }
 
 class TestServiceWithOnMetadataException extends TestService {
+  @override
   void $onMetadata(ServiceCall context) {
     throw Exception('business exception');
   }
@@ -58,10 +60,10 @@ class FixedConnectionClientChannel extends ClientChannelBase {
   ClientConnection createConnection() => clientConnection;
 }
 
-main() async {
+Future<void> main() async {
   testTcpAndUds('round trip insecure connection', (address) async {
     // round trip test of insecure connection.
-    final Server server = Server([TestService()]);
+    final server = Server([TestService()]);
     await server.serve(address: address, port: 0);
 
     final channel = FixedConnectionClientChannel(Http2ClientConnection(
@@ -77,7 +79,7 @@ main() async {
 
   testTcpAndUds('round trip with outgoing and incoming compression',
       (address) async {
-    final Server server = Server(
+    final server = Server(
         [TestService()], const [], CodecRegistry(codecs: const [GzipCodec()]));
     await server.serve(address: address, port: 0);
 
@@ -101,7 +103,7 @@ main() async {
 
   testTcpAndUds('round trip secure connection', (address) async {
     // round trip test of secure connection.
-    final Server server = Server([TestService()]);
+    final server = Server([TestService()]);
     await server.serve(
         address: address,
         port: 0,
@@ -124,7 +126,7 @@ main() async {
   });
 
   test('exception in onMetadataException', () async {
-    final Server server = Server([TestServiceWithOnMetadataException()]);
+    final server = Server([TestServiceWithOnMetadataException()]);
     await server.serve(address: 'localhost', port: 0);
 
     final channel = FixedConnectionClientChannel(Http2ClientConnection(
@@ -140,7 +142,7 @@ main() async {
   });
 
   test('cancellation of streaming subscription propagates properly', () async {
-    final Server server = Server([TestService()]);
+    final server = Server([TestService()]);
     await server.serve(address: 'localhost', port: 0);
 
     final channel = FixedConnectionClientChannel(Http2ClientConnection(

test/server_handles_broken_connection_test.dart

@@ -21,6 +21,7 @@ class TestClient extends grpc.Client {
 }
 
 class TestService extends grpc.Service {
+  @override
   String get $name => 'test.TestService';
   final void Function() finallyCallback;
 
@@ -31,7 +32,7 @@ class TestService extends grpc.Service {
 
   Stream<int> infiniteStream(
       grpc.ServiceCall call, Future<int> request) async* {
-    int count = await request;
+    var count = await request;
     try {
       while (true) {
         count++;
@@ -70,9 +71,9 @@ void client(clientData) async {
   });
 }
 
-main() async {
+Future<void> main() async {
   testTcpAndUds(
-      "the client interrupting the connection does not crash the server",
+      'the client interrupting the connection does not crash the server',
       (address) async {
     // interrrupt the connect of client, the server does not crash.
     late grpc.Server server;

test/server_test.dart

@@ -169,7 +169,7 @@ void main() {
 
   test('Server returns encoded error for unary call', () async {
     Future<int> methodHandler(ServiceCall call, Future<int> request) async {
-      throw GrpcError.unknown("エラー");
+      throw GrpcError.unknown('エラー');
     }
 
     harness
@@ -303,7 +303,7 @@ void main() {
       }
 
       final Interceptor interceptor = (call, method) {
-        if (method.name == "Unary") {
+        if (method.name == 'Unary') {
           return null;
         }
         return GrpcError.unauthenticated('Request is unauthenticated');
@@ -325,7 +325,7 @@ void main() {
 
     group('returns error if interceptor blocks request', () {
       final Interceptor interceptor = (call, method) {
-        if (method.name == "Unary") {
+        if (method.name == 'Unary') {
           return GrpcError.unauthenticated('Request is unauthenticated');
         }
         return null;

test/src/client_utils.dart

@@ -62,16 +62,23 @@ class FakeClientTransportConnection extends Http2ClientConnection {
 Duration testBackoff(Duration? lastBackoff) => const Duration(milliseconds: 1);
 
 class FakeChannelOptions implements ChannelOptions {
+  @override
   ChannelCredentials credentials = const ChannelCredentials.secure();
+  @override
   Duration idleTimeout = const Duration(seconds: 1);
+  @override
   Duration connectionTimeout = const Duration(seconds: 10);
+  @override
   String userAgent = 'dart-grpc/1.0.0 test';
+  @override
   BackoffStrategy backoffStrategy = testBackoff;
+  @override
   CodecRegistry codecRegistry = CodecRegistry.empty();
 }
 
 class FakeChannel extends ClientChannel {
   final Http2ClientConnection connection;
+  @override
   final FakeChannelOptions options;
 
   FakeChannel(String host, this.connection, this.options)
@@ -83,6 +90,7 @@ class FakeChannel extends ClientChannel {
 
 class FakeClientConnectorChannel extends ClientTransportConnectorChannel {
   final Http2ClientConnection connection;
+  @override
   final FakeChannelOptions options;
 
   FakeClientConnectorChannel(
@@ -106,7 +114,7 @@ class TestClient extends Client {
   TestClient(base.ClientChannel channel,
       {CallOptions? options,
       Iterable<ClientInterceptor>? interceptors,
-      this.decode: mockDecode})
+      this.decode = mockDecode})
       : super(channel, options: options, interceptors: interceptors) {
     _$unary = ClientMethod<int, int>('/Test/Unary', mockEncode, decode);
     _$clientStreaming =
@@ -255,7 +263,7 @@ abstract class _Harness {
       List<MessageHandler> serverHandlers = const [],
       void Function()? doneHandler,
       bool expectDone = true}) async {
-    int serverHandlerIndex = 0;
+    var serverHandlerIndex = 0;
     void handleServerMessage(StreamMessage message) {
       serverHandlers[serverHandlerIndex++](message);
     }

test/src/server_utils.dart

@@ -91,7 +91,9 @@ class TestInterceptor {
 }
 
 class TestServerStream extends ServerTransportStream {
+  @override
   final Stream<StreamMessage> incomingMessages;
+  @override
   final StreamSink<StreamMessage> outgoingMessages;
 
   TestServerStream(this.incomingMessages, this.outgoingMessages);
@@ -106,7 +108,7 @@ class TestServerStream extends ServerTransportStream {
   }
 
   @override
-  set onTerminated(void value(int x)) {}
+  set onTerminated(void Function(int x) value) {}
 
   @override
   bool get canPush => true;
@@ -162,7 +164,7 @@ abstract class _Harness {
   }
 
   void setupTest(List<MessageHandler> handlers) {
-    int handlerIndex = 0;
+    var handlerIndex = 0;
     void handleMessages(StreamMessage message) {
       handlers[handlerIndex++](message);
     }
@@ -204,7 +206,7 @@ abstract class _Harness {
       validateResponseHeaders(header.metadata);
     }
 
-    int responseIndex = 0;
+    var responseIndex = 0;
     void handleResponse(StreamMessage message) {
       final response = validateDataMessage(message);
       expect(mockDecode(response.data), expectedResponses[responseIndex++]);

test/src/utils.dart

@@ -27,8 +27,7 @@ List<int> mockEncode(int value) => List.filled(value, 0);
 int mockDecode(List<int> value) => value.length;
 
 Map<String, String> headersToMap(List<Header> headers) =>
-    Map.fromIterable(headers,
+    {for (var h in headers) ascii.decode(h.name): ascii.decode(h.value)};
-        key: (h) => ascii.decode(h.name), value: (h) => ascii.decode(h.value));
 
 void validateRequestHeaders(Map<String, String> headers,
     {String? path,

test/timeline_test.dart

@@ -40,6 +40,7 @@ class TestClient extends Client {
 }
 
 class TestService extends Service {
+  @override
   String get $name => 'test.TestService';
 
   TestService() {
@@ -84,6 +85,7 @@ class FakeTimelineTask extends Fake implements TimelineTask {
 
   bool get isComplete => _startFinishCount == 0;
 
+  @override
   void start(String name, {Map? arguments}) {
     events.add({
       'id': id,
@@ -98,6 +100,7 @@ class FakeTimelineTask extends Fake implements TimelineTask {
     ++_startFinishCount;
   }
 
+  @override
   void instant(String name, {Map? arguments}) {
     events.add({
       'id': id,
@@ -110,6 +113,7 @@ class FakeTimelineTask extends Fake implements TimelineTask {
     });
   }
 
+  @override
   void finish({Map? arguments}) {
     events.add({
       'id': id,
@@ -128,8 +132,8 @@ TimelineTask fakeTimelineTaskFactory(
         {String? filterKey, TimelineTask? parent}) =>
     FakeTimelineTask(filterKey: filterKey, parent: parent);
 
-testee() async {
+Future<void> testee() async {
-  final Server server = Server([TestService()]);
+  final server = Server([TestService()]);
   await server.serve(address: 'localhost', port: 0);
   isTimelineLoggingEnabled = true;
   timelineTaskFactory = fakeTimelineTaskFactory;
@@ -171,7 +175,7 @@ void checkWriteEvent(List<Map> events) {
 void checkReceiveEvent(List<Map> events) {
   events = events.where((e) => e['name'] == 'Data received').toList();
   expect(events.length, equals(3));
-  int sum = 0;
+  var sum = 0;
   for (final e in events) {
     expect(e['id'], 1);
     // 3 elements are 1, 2 and 3.
@@ -200,7 +204,7 @@ void checkFinishEvent(List<Map> events) {
   expect(e.length, 2);
 }
 
-main([args = const <String>[]]) {
+void main([args = const <String>[]]) {
   test('Test gRPC timeline logging', () async {
     await testee();
     for (final task in FakeTimelineTask.tasks) {

test/timeout_test.dart

@@ -73,7 +73,7 @@ void main() {
     test('Calls time out if deadline is exceeded', () async {
       void handleRequest(StreamMessage message) {
         validateDataMessage(message);
-        final Future delay = Future.delayed(Duration(milliseconds: 2));
+        final delay = Future.delayed(Duration(milliseconds: 2));
         expect(delay, completes);
         delay.then((_) {
           try {