Add support for patching class methods.

pkg/analyzer/test/src/dart/sdk/patch_test.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // 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:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/dart/sdk/patch.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart';
@@ skipping 16 matching lines @@
   Folder sdkFolder;
   FolderBasedDartSdk sdk;
 
   SdkPatcher patcher = new SdkPatcher();
   RecordingErrorListener listener = new RecordingErrorListener();
 
   void setUp() {
     sdkFolder = provider.getFolder(_p('/sdk'));
   }
 
+  test_class_getter_append() {
+    CompilationUnit unit = _doTopLevelPatching(
+        r'''
+class C {
+  void a() {}
+}
+''',
+        r'''
+@patch
+class C {
+  int get _b => 2;
+}
+''');
+    _assertUnitCode(unit, 'class C {void a() {} int get _b => 2;}');
+  }
+
+  test_class_method_append() {
+    CompilationUnit unit = _doTopLevelPatching(
+        r'''
+class C {
+  void a() {}
+}
+''',
+        r'''
+@patch
+class C {
+  void _b() {}
+  void _c() {}
+}
+''');
+    _assertUnitCode(unit, 'class C {void a() {} void _b() {} void _c() {}}');
+    ClassDeclaration clazz = unit.declarations[0];
+    MethodDeclaration a = clazz.members[0];
+    MethodDeclaration b = clazz.members[1];
+    MethodDeclaration c = clazz.members[2];
+    _assertPrevNextToken(a.endToken, b.beginToken);
+    _assertPrevNextToken(b.endToken, c.beginToken);
+    _assertPrevNextToken(c.endToken, clazz.rightBracket);
+  }
+
+  test_class_method_fail_notPrivate() {
+    expect(() {
+      _doTopLevelPatching(
+          r'''
+class A {}
+''',
+          r'''
+@patch
+class A {
+  void m() {}
+}
+''');
+    }, throwsArgumentError);
+  }
+
+  test_class_method_patch() {
+    CompilationUnit unit = _doTopLevelPatching(
+        r'''
+class C {
+  external int m();
+}
+''',
+        r'''
+@patch
+class C {
+  @patch
+  int m() => 42;
+}
+''');
+    _assertUnitCode(unit, 'class C {int m() => 42;}');
+    ClassDeclaration clazz = unit.declarations[0];
+    MethodDeclaration m = clazz.members[0];
+    expect(m.externalKeyword, isNull);
+    _assertPrevNextToken(m.parameters.rightParenthesis, m.body.beginToken);
+    _assertPrevNextToken(m.body.endToken, clazz.rightBracket);
+  }
+
+  test_class_method_patch_fail_noExternalKeyword() {
+    expect(() {
+      _doTopLevelPatching(
+          r'''
+class C {
+  int m();
+}
+''',
+          r'''
+@patch
+class C {
+  @patch
+  int m() => 42;
+}
+''');
+    }, throwsArgumentError);
+  }
+
+  test_class_setter_append() {
+    CompilationUnit unit = _doTopLevelPatching(
+        r'''
+class C {
+  void a() {}
+}
+''',
+        r'''
+@patch
+class C {
+  void set _b(_) {}
+}
+''');
+    _assertUnitCode(unit, 'class C {void a() {} void set _b(_) {}}');
+  }
+
   test_directive_fail_export() {
     expect(() {
       _doTopLevelPatching(
           r'''
 import 'a.dart';
 ''',
           r'''
 export 'c.dart';
 ''');
     }, throwsArgumentError);
@@ skipping 33 matching lines @@
     patches: {VM_PLATFORM: ['does_not_exists.dart']}),
 };''');
       _createSdk();
       File file = provider.newFile(_p('/sdk/lib/test/test.dart'), '');
       Source source = file.createSource(FastUri.parse('dart:test'));
       CompilationUnit unit = SdkPatcher.parse(source, true, listener);
       patcher.patch(sdk, SdkLibraryImpl.VM_PLATFORM, listener, source, unit);
     }, throwsArgumentError);
   }
 
+  test_topLevel_class_append() {
+    CompilationUnit unit = _doTopLevelPatching(
+        r'''
+class A {}
+''',
+        r'''
+class _B {
+  void mmm() {}
+}
+''');
+    _assertUnitCode(unit, 'class A {} class _B {void mmm() {}}');
+    ClassDeclaration a = unit.declarations[0];
+    ClassDeclaration b = unit.declarations[1];
+    _assertPrevNextToken(a.endToken, b.beginToken);
+  }
+
+  test_topLevel_class_fail_mixinApplication() {
+    expect(() {
+      _doTopLevelPatching(
+          r'''
+class A {}
+''',
+          r'''
+class _B {}
+class _C = Object with _B;
+''');
+    }, throwsArgumentError);
+  }
+
+  test_topLevel_class_fail_notPrivate() {
+    expect(() {
+      _doTopLevelPatching(
+          r'''
+class A {}
+''',
+          r'''
+class B {}
+''');
+    }, throwsArgumentError);
+  }
+
   test_topLevel_fail_topLevelVariable() {
     expect(() {
       _doTopLevelPatching(
           r'''
 int foo() => 0;
 ''',
           r'''
 int _bar;
 ''');
     }, throwsArgumentError);
@@ skipping 194 matching lines @@
   void _setSdkLibraries(String code) {
     provider.newFile(
         _p('/sdk/lib/_internal/sdk_library_metadata/lib/libraries.dart'), code);
   }
 
   static void _assertPrevNextToken(Token prev, Token next) {
     expect(prev.next, same(next));
     expect(next.previous, same(prev));
   }
 }