Add integration tests for edit.getAssists and edit.getFixes.

pkg/analysis_server/test/integration/edit/get_assists_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 'package:analysis_server/plugin/protocol/protocol.dart';
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import '../integration_tests.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(GetAssistsTest);
+  });
+}
+
+@reflectiveTest
+class GetAssistsTest extends AbstractAnalysisServerIntegrationTest {
+  test_has_assists() async {
+    String pathname = sourcePath('test.dart');
+    String text = r'''
+import 'dart:async';
+
+Future f;
+''';
+    writeFile(pathname, text);
+    standardAnalysisSetup();
+
+    await analysisFinished;
+    expect(currentAnalysisErrors[pathname], isEmpty);
+
+    // expect at least one assist (add show combinator to the dart:async import)
+    EditGetAssistsResult result =
+        await sendEditGetAssists(pathname, text.indexOf('dart:async'), 0);
+    expect(result.assists, isNotEmpty);
+
+    // apply it and make sure that the code analyzing cleanly
+    SourceChange change = result.assists.singleWhere((SourceChange change) =>
+        change.message == "Add explicit 'show' combinator");
+    expect(change.edits, hasLength(1));
+    expect(change.edits.first.edits, hasLength(1));
+    SourceEdit edit = change.edits.first.edits.first;
+    text = text.replaceRange(edit.offset, edit.end, edit.replacement);
+    writeFile(pathname, text);
+
+    await analysisFinished;
+    expect(currentAnalysisErrors[pathname], isEmpty);
+  }
+
+  @override
+  bool get enableNewAnalysisDriver => true;
+}