Use FunctionTypedElement.type while generating method overrides

Turns out `FunctionTypedElement.typeParameters` could be inconsistent
for `MethodMember`s returned by `InheritanceManager3.getMember2`.
`FunctionTypedElement.type.typeFormals` seem to be always good, but
we have to also use `type.parameters` and `type.returnType` instead
of just `parameters` and `returnType` in this case.

Fixes #658

PiperOrigin-RevId: 545681214

Author: Ilya Yanok

lib/src/builder.dart

@@ -1315,8 +1315,8 @@ class _MockClassInfo {
   void _buildOverridingMethod(MethodBuilder builder, MethodElement method) {
     var name = method.displayName;
     if (method.isOperator) name = 'operator$name';
-    final returnType = method.returnType;
-    _withTypeParameters(method.typeParameters, (typeParamsWithBounds, _) {
+    final returnType = method.type.returnType;
+    _withTypeParameters(method.type.typeFormals, (typeParamsWithBounds, _) {
       builder
         ..name = name
         ..annotations.add(referImported('override', 'dart:core'))
@@ -1333,7 +1333,7 @@ class _MockClassInfo {
       final invocationNamedArgs = <Expression, Expression>{};
 
       var position = 0;
-      for (final parameter in method.parameters) {
+      for (final parameter in method.type.parameters) {
         if (parameter.isRequiredPositional || parameter.isOptionalPositional) {
           final superParameterType =
               _escapeCovariance(parameter, position: position);
@@ -1370,7 +1370,7 @@ class _MockClassInfo {
 
       final fallbackGenerator = fallbackGenerators[method.name];
       final parametersContainPrivateName =
-          method.parameters.any((p) => p.type.containsPrivateName);
+          method.type.parameters.any((p) => p.type.containsPrivateName);
       final throwsUnsupported = fallbackGenerator == null &&
           (returnType.containsPrivateName || parametersContainPrivateName);
 
@@ -1443,7 +1443,7 @@ class _MockClassInfo {
       ExecutableElement method, ExecutableElement function) {
     final positionalArguments = <Expression>[];
     final namedArguments = <String, Expression>{};
-    for (final parameter in method.parameters) {
+    for (final parameter in method.type.parameters) {
       if (parameter.isPositional) {
         positionalArguments.add(refer(parameter.name));
       } else if (parameter.isNamed) {
@@ -1453,7 +1453,7 @@ class _MockClassInfo {
     final functionReference =
         referImported(function.name, _typeImport(function));
     return functionReference.call(positionalArguments, namedArguments, [
-      for (final t in method.typeParameters)
+      for (final t in method.type.typeFormals)
         _typeParameterReference(t, withBound: false)
     ]);
   }

test/builder/custom_mocks_test.dart

@@ -1843,6 +1843,29 @@ void main() {
     expect(mocksContent, contains('Iterable<X1> m1<X1>(X1 Function(X)? f)'));
     expect(mocksContent, contains('Iterable<X1?> m2<X1>(X1 Function(X)? f)'));
   });
+  test('We preserve nested generic bounded type arguments', () async {
+    final mocksContent = await buildWithNonNullable({
+      ...annotationsAsset,
+      'foo|lib/foo.dart': dedent(r'''
+            class Foo<A, B> {}
+            abstract class Bar<T> {
+              X m1<X extends Foo<Foo<X, T>, X>>(X Function(T)? f);
+            }
+            abstract class FooBar<X> extends Bar<X> {}
+        '''),
+      'foo|test/foo_test.dart': '''
+            import 'package:foo/foo.dart';
+            import 'package:mockito/annotations.dart';
+
+            @GenerateMocks([FooBar])
+            void main() {}
+          '''
+    });
+    expect(
+        mocksContent,
+        contains(
+            'X1 m1<X1 extends _i2.Foo<_i2.Foo<X1, X>, X1>>(X1 Function(X)? f)'));
+  });
 }
 
 TypeMatcher<List<int>> _containsAllOf(a, [b]) => decodedMatches(