Add an integration test for edit.format.

pkg/analysis_server/test/integration/edit/format_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(FormatTest);
+  });
+}
+
+@reflectiveTest
+class FormatTest extends AbstractAnalysisServerIntegrationTest {
+  String formatTestSetup({bool withErrors: false}) {
+    String pathname = sourcePath('test.dart');
+
+    if (withErrors) {
+      String text = r'''
+class Class1 {
+  int field
+  void foo() {
+  }
+}
+''';
+      writeFile(pathname, text);
+    } else {
+      String text = r'''
+class Class1 {
+  int field;
+
+  void foo() {
+  }
+
+  void bar() {
+  }
+}
+''';
+      writeFile(pathname, text);
+    }
+    standardAnalysisSetup();
+    return pathname;
+  }
+
+  test_format() async {
+    String pathname = formatTestSetup();
+
+    EditFormatResult result = await sendEditFormat(pathname, 0, 0);
+    expect(result.edits, isNotEmpty);
+    expect(result.selectionOffset, 0);
+    expect(result.selectionLength, 0);
+  }
+
+  test_format_preserve_selection() async {
+    String pathname = formatTestSetup();
+
+    // format with 'bar' selected
+    int initialPosition = readFile(pathname).indexOf('bar()');
+    EditFormatResult result =
+        await sendEditFormat(pathname, initialPosition, 'bar'.length);
+    expect(result.edits, isNotEmpty);
+    expect(result.selectionOffset, initialPosition - 3);
+    expect(result.selectionLength, 'bar'.length);
+  }
+
+  test_format_with_errors() async {
+    String pathname = formatTestSetup(withErrors: true);
+
+    try {
+      await sendEditFormat(pathname, 0, 0);
+      fail('expected FORMAT_WITH_ERRORS');
+    } on ServerErrorMessage catch (message) {
+      expect(message.error['code'], 'FORMAT_WITH_ERRORS');
+    }
+  }
+
+  @override
+  bool get enableNewAnalysisDriver => true;
+}