Add support for generic type arguments in annotations

reflectable/lib/src/builder_implementation.dart

@@ -152,7 +152,7 @@ class _ReflectionWorld {
           await reflector._generateCode(this, importCollector, typedefs);
       if (typedefs.isNotEmpty) {
         for (DartType dartType in typedefs.keys) {
-          String body = await reflector._typeCodeOfTypeArgument(
+          String body = await _ReflectorDomain._typeCodeOfTypeArgument(
               dartType, importCollector, typeVariablesInScope, typedefs,
               useNameOfGenericFunctionType: false);
           typedefsCode +=
@@ -1918,7 +1918,7 @@ class _ReflectorDomain {
   /// Returns true iff the given [type] is not and does not contain a free
   /// type variable. [typeVariablesInScope] gives the names of type variables
   /// which are in scope (and hence not free in the relevant context).
-  bool _hasNoFreeTypeVariables(DartType type,
+  static bool _hasNoFreeTypeVariables(DartType type,
       [Set<String>? typeVariablesInScope]) {
     if (type is TypeParameterType &&
         (typeVariablesInScope == null ||
@@ -1951,7 +1951,7 @@ class _ReflectorDomain {
   /// is used to decide whether the output should be a simple `typedef`
   /// name or a fully spelled-out generic function type (and it has no
   /// effect when [dartType] is not a generic function type).
-  Future<String> _typeCodeOfTypeArgument(
+  static Future<String> _typeCodeOfTypeArgument(
       DartType dartType,
       _ImportCollector importCollector,
       Set<String> typeVariablesInScope,
@@ -1963,8 +1963,7 @@ class _ReflectorDomain {
           'Attempt to generate code for an '
           'unsupported kind of type: $dartType (${dartType.runtimeType}). '
           'Generating `dynamic`.',
-          element,
-          _resolver));
+          element));
       return 'dynamic';
     }
 
@@ -5034,7 +5033,20 @@ Future<String> _extractMetadataCode(Element element, Resolver resolver,
       if (_isPrivateName(name)) {
         await _severe('Cannot access private name $name', element);
       }
-      metadataParts.add('const $prefix$name($arguments)');
+      var typeArguments = annotationNode.typeArguments;
+      if (typeArguments != null) {
+        var typedefs = <FunctionType, int>{};
+        var typeVariablesInScope = <String>{}; // None at top level.
+
+        final typeArgumentsList = typeArguments.arguments.map((annotation) => annotation.type);
+        final typeArgumentsString = (await Future.wait(typeArgumentsList.map((type) async =>
+            type != null ? await _ReflectorDomain._typeCodeOfTypeArgument(type, importCollector, typeVariablesInScope, typedefs, useNameOfGenericFunctionType: false) : 'dynamic'
+        ))).join(', ');
+        // print(typeArgumentsString);
+        metadataParts.add('const $prefix$name<$typeArgumentsString>($arguments)');
+      } else {
+        metadataParts.add('const $prefix$name($arguments)');
+      }
     } else {
       // A field reference.
       if (_isPrivateName(annotationNode.name.name)) {
@@ -5641,7 +5653,7 @@ Future<void> _fine(String message,
 /// Returns a string containing the given [message] and identifying the
 /// associated source code location as the location of the given [target].
 Future<String> _formatDiagnosticMessage(
-    String message, Element? target, Resolver resolver) async {
+    String message, Element? target, [Resolver? resolver]) async {
   Source? source = target?.source;
   if (source == null) return message;
   String locationString = '';
@@ -5651,7 +5663,8 @@ Future<String> _formatDiagnosticMessage(
   var targetLibrary = target?.library;
   if (targetLibrary != null &&
       nameOffset != null &&
-      !_isPlatformLibrary(targetLibrary)) {
+      !_isPlatformLibrary(targetLibrary) &&
+      resolver != null) {
     final resolvedLibrary = await _getResolvedLibrary(targetLibrary, resolver);
     if (resolvedLibrary != null) {
       final targetDeclaration = resolvedLibrary.getElementDeclaration(target!);

test_reflectable/test/generic_metadata_test.dart

@@ -0,0 +1,94 @@
+@c
+library test_reflectable.test.generic_metadata_test;
+
+import 'package:reflectable/reflectable.dart';
+import 'package:test/test.dart';
+import 'generic_metadata_test.reflectable.dart';
+
+class MyReflectable extends Reflectable {
+  const MyReflectable()
+      : super(metadataCapability, instanceInvokeCapability,
+            staticInvokeCapability, declarationsCapability, libraryCapability);
+}
+
+const myReflectable = MyReflectable();
+
+const b = 0;
+
+const c = [
+  Bar<num>({'a': 14})
+];
+
+const d = true;
+
+class K {
+  static const p = 2;
+}
+
+@myReflectable
+@Bar<Object?>({
+  b: deprecated,
+  c: Deprecated('tomorrow'),
+  1 + 2: (d ? 3 : 4),
+  identical(1, 2): 's',
+  K.p: 6
+})
+@Bar<Never>({})
+@Bar<void>.namedConstructor({})
+@c
+class Foo {
+  @Bar<bool>({})
+  @Bar<Bar<Bar>>({})
+  @Bar<MyReflectable>.namedConstructor({})
+  @Bar<void Function()>.namedConstructor({})
+  @c
+  void foo() {}
+  var x = 10;
+}
+
+class Bar<X> {
+  final Map<Object, X> m;
+  const Bar(this.m);
+  const Bar.namedConstructor(this.m);
+
+  @override
+  String toString() => 'Bar<$X>($m)';
+}
+
+void main() {
+  initializeReflectable();
+
+  test('metadata on class', () {
+    expect(myReflectable.reflectType(Foo).metadata, const [
+      MyReflectable(),
+      Bar<Object?>({
+        b: deprecated,
+        c: Deprecated('tomorrow'),
+        3: 3,
+        false: 's',
+        2: 6,
+      }),
+      [
+        Bar<num>({'a': 14})
+      ],
+    ]);
+
+    var fooMirror = myReflectable.reflectType(Foo) as ClassMirror;
+    expect(fooMirror.declarations['foo']!.metadata, const [
+      Bar<bool>({}),
+      Bar<Bar<Bar<dynamic>>>({}),
+      Bar<MyReflectable>({}),
+      Bar<void Function()>({}),
+      [
+        Bar<num>({'a': 14})
+      ],
+    ]);
+
+    // The synthetic accessors do not have metadata.
+    expect(fooMirror.instanceMembers['x']!.metadata, []);
+    expect(fooMirror.instanceMembers['x=']!.metadata, []);
+
+    // Test metadata on libraries
+    expect(myReflectable.reflectType(Foo).owner!.metadata, [c]);
+  });
+}