diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/api/code.dart b/pkg/_fe_analyzer_shared/lib/src/macros/api/code.dart
index 6563aef..e0a09f2 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/api/code.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/api/code.dart
@@ -211,6 +211,18 @@
   });
 }
 
+class OmittedTypeAnnotationCode extends TypeAnnotationCode {
+  final OmittedTypeAnnotation typeAnnotation;
+
+  OmittedTypeAnnotationCode(this.typeAnnotation);
+
+  @override
+  CodeKind get kind => CodeKind.omittedTypeAnnotation;
+
+  @override
+  List<Object> get parts => [typeAnnotation];
+}
+
 /// A piece of code representing a valid named type parameter.
 class TypeParameterCode implements Code {
   final TypeAnnotationCode? bound;
@@ -250,6 +262,7 @@
   functionTypeAnnotation,
   namedTypeAnnotation,
   nullableTypeAnnotation,
+  omittedTypeAnnotation,
   parameter,
   raw,
   typeParameter,
diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/api/introspection.dart b/pkg/_fe_analyzer_shared/lib/src/macros/api/introspection.dart
index c24cd91..cc9ef15 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/api/introspection.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/api/introspection.dart
@@ -56,6 +56,19 @@
   Iterable<TypeAnnotation> get typeArguments;
 }
 
+/// An omitted type annotation.
+///
+/// This will be given whenever there is no explicit type annotation for a
+/// declaration.
+///
+/// These type annotations can still produce valid [Code] objects, which will
+/// result in the inferred type being emitted into the resulting code (or
+/// dynamic).
+///
+/// In the definition phase, you may also ask explicitly for the inferred type
+/// using the `inferType` API.
+abstract class OmittedTypeAnnotation implements TypeAnnotation {}
+
 /// The interface representing a resolved type.
 ///
 /// Resolved types understand exactly what type they represent, and can be
diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/executor.dart b/pkg/_fe_analyzer_shared/lib/src/macros/executor.dart
index c80c9a5..429a635 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/executor.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/executor.dart
@@ -73,8 +73,13 @@
   ///
   /// The [resolveIdentifier] argument should return the import uri to be used
   /// for that identifier.
-  String buildAugmentationLibrary(Iterable<MacroExecutionResult> macroResults,
-      ResolvedIdentifier Function(Identifier) resolveIdentifier);
+  ///
+  /// The [inferOmittedType] argument is used to get the inferred type for a
+  /// given [OmittedTypeAnnotation].
+  String buildAugmentationLibrary(
+      Iterable<MacroExecutionResult> macroResults,
+      ResolvedIdentifier Function(Identifier) resolveIdentifier,
+      TypeAnnotation Function(OmittedTypeAnnotation) inferOmittedType);
 
   /// Tell the executor to shut down and clean up any resources it may have
   /// allocated.
diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/executor/augmentation_library.dart b/pkg/_fe_analyzer_shared/lib/src/macros/executor/augmentation_library.dart
index fd0b26bc..a795bc6 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/executor/augmentation_library.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/executor/augmentation_library.dart
@@ -9,8 +9,10 @@
 /// [MacroExecutor.buildAugmentationLibrary].
 mixin AugmentationLibraryBuilder on MacroExecutor {
   @override
-  String buildAugmentationLibrary(Iterable<MacroExecutionResult> macroResults,
-      ResolvedIdentifier Function(Identifier) resolveIdentifier) {
+  String buildAugmentationLibrary(
+      Iterable<MacroExecutionResult> macroResults,
+      ResolvedIdentifier Function(Identifier) resolveIdentifier,
+      TypeAnnotation Function(OmittedTypeAnnotation) typeInferrer) {
     StringBuffer importsBuffer = new StringBuffer();
     StringBuffer directivesBuffer = new StringBuffer();
     Map<Uri, String> importPrefixes = {};
@@ -51,6 +53,8 @@
             writeDirectivePart('${resolved.staticScope!}.');
           }
           writeDirectivePart('${part.name}');
+        } else if (part is OmittedTypeAnnotation) {
+          buildCode(typeInferrer(part).code);
         } else {
           throw new ArgumentError(
               'Code objects only support String, Identifier, and Code '
diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/executor/executor_base.dart b/pkg/_fe_analyzer_shared/lib/src/macros/executor/executor_base.dart
index b592139..5245960 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/executor/executor_base.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/executor/executor_base.dart
@@ -298,8 +298,10 @@
 
   /// These calls are handled by the higher level executor.
   @override
-  String buildAugmentationLibrary(Iterable<MacroExecutionResult> macroResults,
-          ResolvedIdentifier Function(Identifier) resolveIdentifier) =>
+  String buildAugmentationLibrary(
+          Iterable<MacroExecutionResult> macroResults,
+          ResolvedIdentifier Function(Identifier) resolveIdentifier,
+          TypeAnnotation Function(OmittedTypeAnnotation) inferOmittedType) =>
       throw new StateError('Unreachable');
 
   @override
diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/executor/introspection_impls.dart b/pkg/_fe_analyzer_shared/lib/src/macros/executor/introspection_impls.dart
index 857674e..29c443b 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/executor/introspection_impls.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/executor/introspection_impls.dart
@@ -156,6 +156,18 @@
   }
 }
 
+class OmittedTypeAnnotationImpl extends TypeAnnotationImpl
+    implements OmittedTypeAnnotation {
+  OmittedTypeAnnotationImpl({required int id})
+      : super(id: id, isNullable: false);
+
+  @override
+  TypeAnnotationCode get code => new OmittedTypeAnnotationCode(this);
+
+  @override
+  RemoteInstanceKind get kind => RemoteInstanceKind.omittedTypeAnnotation;
+}
+
 abstract class DeclarationImpl extends RemoteInstance implements Declaration {
   final IdentifierImpl identifier;
 
diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/executor/remote_instance.dart b/pkg/_fe_analyzer_shared/lib/src/macros/executor/remote_instance.dart
index fc45704..098ad02 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/executor/remote_instance.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/executor/remote_instance.dart
@@ -100,6 +100,7 @@
   namedStaticType,
   methodDeclaration,
   namedTypeAnnotation,
+  omittedTypeAnnotation,
   parameterDeclaration,
   staticType,
   typeAliasDeclaration,
diff --git a/pkg/_fe_analyzer_shared/lib/src/macros/executor/serialization_extensions.dart b/pkg/_fe_analyzer_shared/lib/src/macros/executor/serialization_extensions.dart
index d039f7d..81aa885 100644
--- a/pkg/_fe_analyzer_shared/lib/src/macros/executor/serialization_extensions.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/macros/executor/serialization_extensions.dart
@@ -48,6 +48,9 @@
       case RemoteInstanceKind.namedTypeAnnotation:
         moveNext();
         return _expectNamedTypeAnnotation(id) as T;
+      case RemoteInstanceKind.omittedTypeAnnotation:
+        moveNext();
+        return _expectOmittedTypeAnnotation(id) as T;
       case RemoteInstanceKind.parameterDeclaration:
         moveNext();
         return _expectParameterDeclaration(id) as T;
@@ -80,6 +83,13 @@
         typeArguments: (this..moveNext())._expectRemoteInstanceList(),
       );
 
+  OmittedTypeAnnotation _expectOmittedTypeAnnotation(int id) {
+    expectBool(); // Always `false`.
+    return new OmittedTypeAnnotationImpl(
+      id: id,
+    );
+  }
+
   FunctionTypeAnnotation _expectFunctionTypeAnnotation(int id) =>
       new FunctionTypeAnnotationImpl(
         id: id,
@@ -274,6 +284,9 @@
       case CodeKind.nullableTypeAnnotation:
         return new NullableTypeAnnotationCode((this..moveNext()).expectCode())
             as T;
+      case CodeKind.omittedTypeAnnotation:
+        return new OmittedTypeAnnotationCode(RemoteInstance.deserialize(this))
+            as T;
       case CodeKind.parameter:
         return new ParameterCode(
             defaultValue: (this..moveNext()).expectNullableCode(),
@@ -354,6 +367,11 @@
         NullableTypeAnnotationCode self = this as NullableTypeAnnotationCode;
         self.underlyingType.serialize(serializer);
         return;
+      case CodeKind.omittedTypeAnnotation:
+        OmittedTypeAnnotationCode self = this as OmittedTypeAnnotationCode;
+        (self.typeAnnotation as OmittedTypeAnnotationImpl)
+            .serialize(serializer);
+        return;
       case CodeKind.parameter:
         ParameterCode self = this as ParameterCode;
         self.defaultValue.serializeNullable(serializer);
diff --git a/pkg/_fe_analyzer_shared/test/macros/executor/augmentation_library_test.dart b/pkg/_fe_analyzer_shared/test/macros/executor/augmentation_library_test.dart
index af3d9d7..78d960a 100644
--- a/pkg/_fe_analyzer_shared/test/macros/executor/augmentation_library_test.dart
+++ b/pkg/_fe_analyzer_shared/test/macros/executor/augmentation_library_test.dart
@@ -2,6 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:_fe_analyzer_shared/src/macros/executor/introspection_impls.dart';
 import 'package:_fe_analyzer_shared/src/macros/executor/remote_instance.dart';
 import 'package:test/fake.dart';
 import 'package:test/test.dart';
@@ -15,18 +16,26 @@
 
 void main() {
   group('AugmentationLibraryBuilder', () {
+    final intIdentifier = TestIdentifier(
+        id: RemoteInstance.uniqueId,
+        name: 'int',
+        kind: IdentifierKind.topLevelMember,
+        staticScope: null,
+        uri: Uri.parse('dart:core'));
+
     test('can combine multiple execution results', () {
       var results = [
         for (var i = 0; i < 2; i++)
           MacroExecutionResultImpl(classAugmentations: {
             for (var j = 0; j < 3; j++)
               'Foo$i$j': [
-                DeclarationCode.fromString('int get i => $i;\n'),
-                DeclarationCode.fromString('int get j => $j;\n'),
+                DeclarationCode.fromParts([intIdentifier, ' get i => $i;\n']),
+                DeclarationCode.fromParts([intIdentifier, ' get j => $j;\n']),
               ]
           }, libraryAugmentations: [
             for (var j = 0; j < 3; j++)
-              DeclarationCode.fromString('int get i${i}j$j => ${i + j};\n'),
+              DeclarationCode.fromParts(
+                  [intIdentifier, ' get i${i}j$j => ${i + j};\n']),
           ], newTypeNames: [
             'Foo${i}0',
             'Foo${i}1',
@@ -34,37 +43,42 @@
           ]),
       ];
       var library = _TestExecutor().buildAugmentationLibrary(
-          results, (Identifier i) => (i as TestIdentifier).resolved);
+          results,
+          (Identifier i) => (i as TestIdentifier).resolved,
+          (OmittedTypeAnnotation i) =>
+              (i as TestOmittedTypeAnnotation).inferredType);
       expect(library, equalsIgnoringWhitespace('''
-        int get i0j0 => 0;
-        int get i0j1 => 1;
-        int get i0j2 => 2;
-        int get i1j0 => 1;
-        int get i1j1 => 2;
-        int get i1j2 => 3;
+        import 'dart:core' as i0;
+
+        i0.int get i0j0 => 0;
+        i0.int get i0j1 => 1;
+        i0.int get i0j2 => 2;
+        i0.int get i1j0 => 1;
+        i0.int get i1j1 => 2;
+        i0.int get i1j2 => 3;
         augment class Foo00 {
-          int get i => 0;
-          int get j => 0;
+          i0.int get i => 0;
+          i0.int get j => 0;
         }
         augment class Foo01 {
-          int get i => 0;
-          int get j => 1;
+          i0.int get i => 0;
+          i0.int get j => 1;
         }
         augment class Foo02 {
-          int get i => 0;
-          int get j => 2;
+          i0.int get i => 0;
+          i0.int get j => 2;
         }
         augment class Foo10 {
-          int get i => 1;
-          int get j => 0;
+          i0.int get i => 1;
+          i0.int get j => 0;
         }
         augment class Foo11 {
-          int get i => 1;
-          int get j => 1;
+          i0.int get i => 1;
+          i0.int get j => 1;
         }
         augment class Foo12 {
-          int get i => 1;
-          int get j => 2;
+          i0.int get i => 1;
+          i0.int get j => 2;
         }
       '''));
     });
@@ -112,7 +126,9 @@
               '<',
               barIdentifier,
               '<T>> {\n',
-              'late int ${barInstanceMember.name};\n',
+              'late ',
+              intIdentifier,
+              ' ${barInstanceMember.name};\n',
               barIdentifier,
               '<T> build() => new ',
               barIdentifier,
@@ -130,19 +146,50 @@
         )
       ];
       var library = _TestExecutor().buildAugmentationLibrary(
-          results, (Identifier i) => (i as TestIdentifier).resolved);
+          results,
+          (Identifier i) => (i as TestIdentifier).resolved,
+          (OmittedTypeAnnotation i) =>
+              (i as TestOmittedTypeAnnotation).inferredType);
       expect(library, equalsIgnoringWhitespace('''
         import 'package:foo/foo.dart' as i0;
         import 'package:builder/builder.dart' as i1;
         import 'package:bar/bar.dart' as i2;
+        import 'dart:core' as i3;
 
         class FooBuilder<T extends i0.Foo> implements i1.Builder<i2.Bar<T>> {
-          late int baz;
+          late i3.int baz;
 
           i2.Bar<T> build() => new i2.Bar()..baz = i2.Bar.zap;
         }
       '''));
     });
+
+    test('can handle omitted type annotations', () {
+      var results = [
+        MacroExecutionResultImpl(classAugmentations: {}, libraryAugmentations: [
+          DeclarationCode.fromParts([
+            OmittedTypeAnnotationCode(
+                TestOmittedTypeAnnotation(NamedTypeAnnotationImpl(
+              id: RemoteInstance.uniqueId,
+              identifier: intIdentifier,
+              isNullable: false,
+              typeArguments: [],
+            ))),
+            ' x = 1;',
+          ]),
+        ], newTypeNames: []),
+      ];
+      var library = _TestExecutor().buildAugmentationLibrary(
+          results,
+          (Identifier i) => (i as TestIdentifier).resolved,
+          (OmittedTypeAnnotation i) =>
+              (i as TestOmittedTypeAnnotation).inferredType);
+      expect(library, equalsIgnoringWhitespace('''
+        import 'dart:core' as i0;
+
+        i0.int x = 1;
+      '''));
+    });
   });
 }
 
diff --git a/pkg/_fe_analyzer_shared/test/macros/executor/executor_test.dart b/pkg/_fe_analyzer_shared/test/macros/executor/executor_test.dart
index 13b54ac..b5b6240 100644
--- a/pkg/_fe_analyzer_shared/test/macros/executor/executor_test.dart
+++ b/pkg/_fe_analyzer_shared/test/macros/executor/executor_test.dart
@@ -271,7 +271,7 @@
                 expect(
                     result.libraryAugmentations.single.debugString().toString(),
                     equalsIgnoringWhitespace('''
-                String get delegate_myVariable => _myVariable;'''));
+                /*inferred*/String get delegate_myVariable => _myVariable;'''));
               });
 
               test('on fields', () async {
@@ -428,7 +428,7 @@
                         .map((a) => a.debugString().toString()),
                     unorderedEquals([
                       equalsIgnoringWhitespace('''
-                augment String get _myVariable {
+                augment /*inferred*/String get _myVariable {
                   print('parentClass: ');
                   print('isExternal: false');
                   print('isFinal: true');
@@ -436,11 +436,11 @@
                   return augment super;
                 }'''),
                       equalsIgnoringWhitespace('''
-                augment set _myVariable(String value) {
+                augment set _myVariable(/*inferred*/String value) {
                   augment super = value;
                 }'''),
                       equalsIgnoringWhitespace('''
-                augment final String _myVariable = 'new initial value' + augment super;
+                augment final /*inferred*/String _myVariable = 'new initial value' + augment super;
                 '''),
                     ]));
               });
diff --git a/pkg/_fe_analyzer_shared/test/macros/util.dart b/pkg/_fe_analyzer_shared/test/macros/util.dart
index edb0788..43c54f4 100644
--- a/pkg/_fe_analyzer_shared/test/macros/util.dart
+++ b/pkg/_fe_analyzer_shared/test/macros/util.dart
@@ -111,6 +111,14 @@
       (library == other.library && identifier.name == other.identifier.name);
 }
 
+/// Knows its inferred type ahead of time.
+class TestOmittedTypeAnnotation extends OmittedTypeAnnotationImpl {
+  final TypeAnnotation inferredType;
+
+  TestOmittedTypeAnnotation(this.inferredType)
+      : super(id: RemoteInstance.uniqueId);
+}
+
 /// An identifier that knows the resolved version of itself.
 class TestIdentifier extends IdentifierImpl {
   final ResolvedIdentifier resolved;
@@ -137,6 +145,9 @@
         part.debugString(buffer);
       } else if (part is IdentifierImpl) {
         buffer.write(part.name);
+      } else if (part is TestOmittedTypeAnnotation) {
+        buffer.write('/*inferred*/');
+        part.inferredType.code.debugString(buffer);
       } else {
         buffer.write(part as String);
       }
@@ -244,6 +255,7 @@
       identifier: IdentifierImpl(id: RemoteInstance.uniqueId, name: 'String'),
       isNullable: false,
       typeArguments: const []);
+  static final inferredStringType = TestOmittedTypeAnnotation(stringType);
   static final voidType = NamedTypeAnnotationImpl(
       id: RemoteInstance.uniqueId,
       identifier: IdentifierImpl(id: RemoteInstance.uniqueId, name: 'void'),
@@ -271,7 +283,7 @@
       isExternal: false,
       isFinal: true,
       isLate: false,
-      type: stringType);
+      type: inferredStringType);
   static final myVariableGetter = FunctionDeclarationImpl(
       id: RemoteInstance.uniqueId,
       identifier:
diff --git a/pkg/analysis_server/lib/src/services/correction/dart/add_trailing_comma.dart b/pkg/analysis_server/lib/src/services/correction/dart/add_trailing_comma.dart
index 4da7cda..1b4aed0 100644
--- a/pkg/analysis_server/lib/src/services/correction/dart/add_trailing_comma.dart
+++ b/pkg/analysis_server/lib/src/services/correction/dart/add_trailing_comma.dart
@@ -25,16 +25,20 @@
   Future<void> compute(ChangeBuilder builder) async {
     final node = this.node;
     if (node is ArgumentList) {
-      await builder.addDartFileEdit(file, (builder) {
-        builder.addSimpleInsertion(node.arguments.last.end, ',');
-      });
+      await _insertComma(builder, node.arguments.last);
     } else if (node is FormalParameterList) {
-      await builder.addDartFileEdit(file, (builder) {
-        builder.addSimpleInsertion(node.parameters.last.end, ',');
-      });
+      await _insertComma(builder, node.parameters.last);
+    } else if (node is Assertion) {
+      await _insertComma(builder, node.message ?? node.condition);
     }
   }
 
+  Future<void> _insertComma(ChangeBuilder builder, AstNode lastNode) async {
+    await builder.addDartFileEdit(file, (builder) {
+      builder.addSimpleInsertion(lastNode.end, ',');
+    });
+  }
+
   /// Return an instance of this class. Used as a tear-off in `FixProcessor`.
   static AddTrailingComma newInstance() => AddTrailingComma();
 }
diff --git a/pkg/analysis_server/test/src/services/correction/fix/add_trailing_comma_test.dart b/pkg/analysis_server/test/src/services/correction/fix/add_trailing_comma_test.dart
index fe27f30..474e1d8 100644
--- a/pkg/analysis_server/test/src/services/correction/fix/add_trailing_comma_test.dart
+++ b/pkg/analysis_server/test/src/services/correction/fix/add_trailing_comma_test.dart
@@ -72,6 +72,36 @@
   @override
   String get lintCode => LintNames.require_trailing_commas;
 
+  Future<void> test_assert_initializer() async {
+    await resolveTestCode('''
+class C {
+  C(a) : assert(a,
+    '');
+}
+''');
+    await assertHasFix('''
+class C {
+  C(a) : assert(a,
+    '',);
+}
+''');
+  }
+
+  Future<void> test_assert_statement() async {
+    await resolveTestCode('''
+void f(a, b) {
+  assert(a ||
+    b);
+}
+''');
+    await assertHasFix('''
+void f(a, b) {
+  assert(a ||
+    b,);
+}
+''');
+  }
+
   Future<void> test_named() async {
     await resolveTestCode('''
 void f({a, b}) {
diff --git a/pkg/front_end/lib/src/fasta/kernel/macro/macro.dart b/pkg/front_end/lib/src/fasta/kernel/macro/macro.dart
index cdeeaaa3..b004690 100644
--- a/pkg/front_end/lib/src/fasta/kernel/macro/macro.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/macro/macro.dart
@@ -229,6 +229,11 @@
     }
   }
 
+  macro.TypeAnnotation _inferOmittedType(
+      macro.OmittedTypeAnnotation omittedType) {
+    throw new UnimplementedError('This is not yet supported!');
+  }
+
   Iterable<_ApplicationData> get _applicationData {
     if (_applicationDataCache == null) {
       List<_ApplicationData> data = _applicationDataCache = [];
@@ -325,7 +330,8 @@
       SourceLibraryBuilder sourceLibraryBuilder = entry.key;
       assert(entry.value.isNotEmpty);
       String result = _macroExecutor
-          .buildAugmentationLibrary(entry.value, _resolveIdentifier)
+          .buildAugmentationLibrary(
+              entry.value, _resolveIdentifier, _inferOmittedType)
           .trim();
       assert(
           result.trim().isNotEmpty,
@@ -358,8 +364,8 @@
                 typeResolver,
                 classIntrospector);
         if (result.isNotEmpty) {
-          String source = _macroExecutor
-              .buildAugmentationLibrary([result], _resolveIdentifier);
+          String source = _macroExecutor.buildAugmentationLibrary(
+              [result], _resolveIdentifier, _inferOmittedType);
           SourceLibraryBuilder augmentationLibrary = await applicationData
               .libraryBuilder
               .createAugmentationLibrary(source);
@@ -446,7 +452,7 @@
         in results.entries) {
       SourceLibraryBuilder sourceLibraryBuilder = entry.key;
       String result = _macroExecutor.buildAugmentationLibrary(
-          entry.value, _resolveIdentifier);
+          entry.value, _resolveIdentifier, _inferOmittedType);
       assert(
           result.trim().isNotEmpty,
           "Empty definitions phase augmentation library source for "
diff --git a/pkg/front_end/test/macros/declaration/macro_declaration_test.dart b/pkg/front_end/test/macros/declaration/macro_declaration_test.dart
index 27aa722..4eacef3 100644
--- a/pkg/front_end/test/macros/declaration/macro_declaration_test.dart
+++ b/pkg/front_end/test/macros/declaration/macro_declaration_test.dart
@@ -294,8 +294,10 @@
   List<_MacroInstanceIdentifier> macroInstances = [];
 
   @override
-  String buildAugmentationLibrary(Iterable<MacroExecutionResult> macroResults,
-      ResolvedIdentifier Function(Identifier) resolveIdentifier) {
+  String buildAugmentationLibrary(
+      Iterable<MacroExecutionResult> macroResults,
+      ResolvedIdentifier Function(Identifier) resolveIdentifier,
+      TypeAnnotation Function(OmittedTypeAnnotation) inferOmittedType) {
     return '';
   }
 
diff --git a/tests/lib/isolate/spawn_uri__package_uri__test.dart b/tests/lib/isolate/spawn_uri__package_uri__test.dart
index d5efa2c..b212874 100644
--- a/tests/lib/isolate/spawn_uri__package_uri__test.dart
+++ b/tests/lib/isolate/spawn_uri__package_uri__test.dart
@@ -12,6 +12,7 @@
 main() async {
   // Run the Dart VM with or without:
   //     --packages=<packages|package_config>
+  final futures = <Future>[];
   for (final runWithPackagesArg in const [true, false]) {
     // Run the isolate with or without
     //    Isolate.spawnUri(..., packageConfig: <packages|package_config>)
@@ -20,15 +21,16 @@
       print('TEST spawnWithPackageConfig = $spawnWithPackageConfig ');
       final bool checkForResolveUri =
           runWithPackagesArg || !spawnWithPackageConfig;
-      await runDotPackagesTest(
-          runWithPackagesArg, spawnWithPackageConfig, checkForResolveUri);
+      futures.add(runDotPackagesTest(
+          runWithPackagesArg, spawnWithPackageConfig, checkForResolveUri));
       for (final optionalPackageUri in const [true, false]) {
         print('TEST optionalPackageUri = $optionalPackageUri');
-        await runPackageConfigTest(runWithPackagesArg, spawnWithPackageConfig,
-            optionalPackageUri, checkForResolveUri);
+        futures.add(runPackageConfigTest(runWithPackagesArg,
+            spawnWithPackageConfig, optionalPackageUri, checkForResolveUri));
       }
     }
   }
+  await Future.wait(futures);
 }
 
 Future runPackageConfigTest(bool withPackagesArg, bool spawnWithArg,
diff --git a/tests/lib_2/isolate/spawn_uri__package_uri__test.dart b/tests/lib_2/isolate/spawn_uri__package_uri__test.dart
index 46d4a14..23d4707 100644
--- a/tests/lib_2/isolate/spawn_uri__package_uri__test.dart
+++ b/tests/lib_2/isolate/spawn_uri__package_uri__test.dart
@@ -14,6 +14,7 @@
 main() async {
   // Run the Dart VM with or without:
   //     --packages=<packages|package_config>
+  final futures = <Future>[];
   for (final runWithPackagesArg in const [true, false]) {
     // Run the isolate with or without
     //    Isolate.spawnUri(..., packageConfig: <packages|package_config>)
@@ -22,15 +23,16 @@
       print('TEST spawnWithPackageConfig = $spawnWithPackageConfig ');
       final bool checkForResolveUri =
           runWithPackagesArg || !spawnWithPackageConfig;
-      await runDotPackagesTest(
-          runWithPackagesArg, spawnWithPackageConfig, checkForResolveUri);
+      futures.add(runDotPackagesTest(
+          runWithPackagesArg, spawnWithPackageConfig, checkForResolveUri));
       for (final optionalPackageUri in const [true, false]) {
         print('TEST optionalPackageUri = $optionalPackageUri');
-        await runPackageConfigTest(runWithPackagesArg, spawnWithPackageConfig,
-            optionalPackageUri, checkForResolveUri);
+        futures.add(runPackageConfigTest(runWithPackagesArg,
+            spawnWithPackageConfig, optionalPackageUri, checkForResolveUri));
       }
     }
   }
+  await Future.wait(futures);
 }
 
 Future runPackageConfigTest(bool withPackagesArg, bool spawnWithArg,
diff --git a/tools/VERSION b/tools/VERSION
index 748f5d3..e732f20 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 17
 PATCH 0
-PRERELEASE 221
+PRERELEASE 222
 PRERELEASE_PATCH 0
\ No newline at end of file