When reporting an error with an unrevivable parameter, refer to the class-to-mock.

Fixes #540

PiperOrigin-RevId: 459824583

Author: srawlins

lib/src/builder.dart

@@ -1367,11 +1367,11 @@ class _MockClassInfo {
               .code;
         } on _ReviveException catch (e) {
           final method = parameter.enclosingElement!;
-          final clazz = method.enclosingElement!;
           throw InvalidMockitoAnnotationException(
               'Mockito cannot generate a valid override for method '
-              "'${clazz.displayName}.${method.displayName}'; parameter "
-              "'${parameter.displayName}' causes a problem: ${e.message}");
+              "'${mockTarget.classElement.displayName}.${method.displayName}'; "
+              "parameter '${parameter.displayName}' causes a problem: "
+              '${e.message}');
         }
       }
     });

test/builder/auto_mocks_test.dart

@@ -485,6 +485,31 @@ void main() {
     );
   });
 
+  test(
+      'throws when given a parameter default value using a private type, and '
+      'refers to the class-to-mock', () {
+    _expectBuilderThrows(
+      assets: {
+        ...annotationsAsset,
+        ...simpleTestAsset,
+        'foo|lib/foo.dart': dedent(r'''
+      class FooBase {
+        void m([Bar a = const _Bar()]) {}
+      }
+      class Foo extends FooBase {}
+      class Bar {}
+      class _Bar implements Bar {
+        const _Bar();
+      }
+      '''),
+      },
+      message: contains(
+          "Mockito cannot generate a valid override for method 'Foo.m'; "
+          "parameter 'a' causes a problem: default value has a private type: "
+          'asset:foo/lib/foo.dart#_Bar'),
+    );
+  });
+
   test(
       'throws when given a parameter default value using a private constructor',
       () {