Add FileState.hasMixin/hasMixinLibrary properties.

pkg/front_end/test/src/incremental/file_state_test.dart

 // Copyright (c) 2017, 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 'dart:async';
 
 import 'package:front_end/memory_file_system.dart';
 import 'package:front_end/src/fasta/translate_uri.dart';
 import 'package:front_end/src/incremental/file_state.dart';
 import 'package:test/test.dart';
@@ skipping 266 matching lines @@
       expect(export_.combinators[1].names, unorderedEquals(['C']));
       expect(export_.combinators[2].isShow, isTrue);
       expect(export_.combinators[2].names, unorderedEquals(['A', 'D']));
       expect(export_.isExposed('A'), isTrue);
       expect(export_.isExposed('B'), isFalse);
       expect(export_.isExposed('C'), isFalse);
       expect(export_.isExposed('D'), isTrue);
     }
   }
 
+  test_hasMixin_false() async {
+    writeFile(
+        '/a.dart',
+        r'''
+class A {}
+class B extends Object with A {}
+''');
+    var uri = writeFile(
+        '/test.dart',
+        r'''
+import 'a.dart';
+class T1 extends A {}
+class T2 extends B {}
+''');
+    FileState file = await fsState.getFile(uri);
+    expect(file.hasMixin, isFalse);
+  }
+
+  test_hasMixin_true() async {
+    var uri = writeFile(
+        '/test.dart',
+        r'''
+class A {}
+class B extends Object with A {}
+''');
+    FileState file = await fsState.getFile(uri);
+    expect(file.hasMixin, isTrue);
+  }
+
+  test_hasMixinLibrary_false() async {
+    var partUri = writeFile(
+        '/part.dart',
+        r'''
+part of test;
+class A {}
+''');
+    var libUri = writeFile(
+        '/test.dart',
+        r'''
+library test;
+part 'part.dart';
+class B extends A {}
+''');
+
+    FileState part = await fsState.getFile(partUri);
+    FileState lib = await fsState.getFile(libUri);
+
+    expect(part.hasMixin, isFalse);
+    expect(lib.hasMixin, isFalse);
+    expect(lib.hasMixinLibrary, isFalse);
+  }
+
+  test_hasMixinLibrary_true_inDefiningUnit() async {
+    var partUri = writeFile(
+        '/part.dart',
+        r'''
+part of test;
+class A {}
+''');
+    var libUri = writeFile(
+        '/test.dart',
+        r'''
+library test;
+part 'part.dart';
+class B extends Object with A {}
+''');
+
+    FileState part = await fsState.getFile(partUri);
+    FileState lib = await fsState.getFile(libUri);
+
+    expect(part.hasMixin, isFalse);
+    expect(lib.hasMixin, isTrue);
+    expect(lib.hasMixinLibrary, isTrue);
+  }
+
+  test_hasMixinLibrary_true_inPart() async {
+    var partUri = writeFile(
+        '/part.dart',
+        r'''
+part of test;
+class A {}
+class B extends Object with A {}

[ahe, 2017/06/12 19:22:03]

Consider adding a test for a named mixin application as well:

class Named = Object with Mixin {}

[scheglov, 2017/06/12 19:43:19]

Done.

+''');
+    var libUri = writeFile(
+        '/test.dart',
+        r'''
+library test;
+part 'part.dart';
+class C {}
+''');
+
+    FileState part = await fsState.getFile(partUri);
+    FileState lib = await fsState.getFile(libUri);
+
+    expect(part.hasMixin, isTrue);
+    expect(lib.hasMixin, isFalse);
+    expect(lib.hasMixinLibrary, isTrue);
+  }
+
   test_newFileListener() async {
     var a = writeFile('/a.dart', '');
     var b = writeFile('/b.dart', '');
     var c = writeFile(
         '/c.dart',
         r'''
 import 'a.dart';
 ''');
 
     FileState cFile = await fsState.getFile(c);
@@ skipping 94 matching lines @@
   Uri _writeFileDirectives(String path,
       {List<String> imports: const [], List<String> exports: const []}) {
     return writeFile(
         path,
         '''
 ${imports.map((uri) => 'import "$uri";').join('\n')}
 ${exports.map((uri) => 'export "$uri";').join('\n')}
 ''');
   }
 }