Partial support for intelligent paste operation

pkg/analysis_server/test/src/computer/import_elements_computer_test.dart

Index: pkg/analysis_server/test/src/computer/import_elements_computer_test.dart
diff --git a/pkg/analysis_server/test/src/computer/import_elements_computer_test.dart b/pkg/analysis_server/test/src/computer/import_elements_computer_test.dart
index cb7f56164bfe9784973218e279945d96deb3ceb2..36a0b1913128e6da8b6ad98bd513740398d486db 100644
--- a/pkg/analysis_server/test/src/computer/import_elements_computer_test.dart
+++ b/pkg/analysis_server/test/src/computer/import_elements_computer_test.dart
@@ -2,10 +2,13 @@
 // 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:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/computer/import_elements_computer.dart';
-import 'package:analyzer/dart/analysis/results.dart';
+import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
+import 'package:front_end/src/base/source.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -17,60 +20,294 @@ main() {
   });
 }
 
-/**
- * Tests that the [ImportElementsComputer] will correctly update imports. The
- * tests are generally labeled based on the kind of import in the source (from
- * which the text was copied) and the kind of import in the target (into which
- * the text was pasted). Kinds are a combination of "prefix", "hide", "show" and
- * "deferred", or "bare" when there are none of the previous, or "none" when
- * there is no import.
- */
 @reflectiveTest
 class ImportElementsComputerTest extends AbstractContextTest {
-  String targetPath;
-  String targetCode;
+  String path;
+  String originalContent;
+  ImportElementsComputer computer;
+  SourceFileEdit sourceFileEdit;
 
-  ResolveResult result;
+  void assertChanges(String expectedContent) {
+    String resultCode =
+        SourceEdit.applySequence(originalContent, sourceFileEdit.edits);
+    expect(resultCode, expectedContent);
+  }
 
-  setUp() async {
-    super.setUp();
-    packageMap['p'] = [provider.newFolder(provider.convertPath('/p/lib'))];
-    targetPath = provider.convertPath('/p/lib/target.dart');
-    targetCode = '''
-main() {}
-''';
-    provider.newFile(targetPath, targetCode);
-    result = await driver.getResult(targetPath);
-  }
-
-  @failingTest
-  test_bare_none() {
-    List<ImportedElements> elements = <ImportedElements>[
-      new ImportedElements(
-          provider.convertPath('/p/lib/a.dart'), '', <String>['A']),
-    ];
-    List<SourceEdit> edits = _computeEditsFor(elements);
+  void assertNoChanges() {
+    expect(sourceFileEdit.edits, isEmpty);
+  }
+
+  Future<Null> computeChanges(List<ImportedElements> importedElements) async {
+    SourceChange change = await computer.createEdits(importedElements);
+    expect(change, isNotNull);
+    List<SourceFileEdit> edits = change.edits;
     expect(edits, hasLength(1));
-    SourceEdit edit = edits[0];
-    expect(edit, isNotNull);
-    expect(edit.offset, 0);
-    expect(edit.length, 0);
-    expect(edit.apply(targetCode), """
-import 'source.dart';
+    sourceFileEdit = edits[0];
+    expect(sourceFileEdit, isNotNull);
+  }
+
+  Future<Null> createBuilder(String content) async {
+    originalContent = content;
+    provider.newFile(path, content);
+    AnalysisResult result = await driver.getResult(path);
+    computer = new ImportElementsComputer(provider, result);
+  }
+
+  void setUp() {
+    super.setUp();
+    path = provider.convertPath('/test.dart');
+  }
+
+  test_createEdits_addImport_noPrefix() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' as foo;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' as foo;
+import 'package:pkg/foo.dart';
+''');
+  }
+
+  test_createEdits_addImport_prefix() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart';
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, 'foo', <String>['A'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart';
+import 'package:pkg/foo.dart' as foo;
+''');
+  }
+
+  test_createEdits_addShow_multipleNames() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' show B;
+import 'package:pkg/foo.dart' as foo;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A', 'C'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' show B, A, C;
+import 'package:pkg/foo.dart' as foo;
+''');
+  }
+
+  test_createEdits_addShow_removeHide() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' show A, B hide C, D;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['C'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' show A, B, C hide D;
+''');
+  }
+
+  test_createEdits_addShow_singleName_noPrefix() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' show B;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' show B, A;
+''');
+  }
+
+  test_createEdits_addShow_singleName_prefix() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' show C;
+import 'package:pkg/foo.dart' as foo show B;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, 'foo', <String>['A'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' show C;
+import 'package:pkg/foo.dart' as foo show B, A;
+''');
+  }
+
+  test_createEdits_alreadyImported_noCombinators() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart';
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A', 'B'])
+    ]);
+    assertNoChanges();
+  }
+
+  test_createEdits_alreadyImported_withPrefix() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' as foo;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, 'foo', <String>['A', 'B'])
+    ]);
+    assertNoChanges();
+  }
+
+  test_createEdits_alreadyImported_withShow() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' show A;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A'])
+    ]);
+    assertNoChanges();
+  }
+
+  test_createEdits_noElements() async {
+    await createBuilder('');
+    await computeChanges(<ImportedElements>[]);
+    assertNoChanges();
+  }
+
+  test_createEdits_removeHide_firstInCombinator() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A, B, C;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide B, C;
+''');
+  }
+
+  test_createEdits_removeHide_lastInCombinator() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A, B, C;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['C'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide A, B;
+''');
+  }
+
+  test_createEdits_removeHide_middleInCombinator() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A, B, C;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['B'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide A, C;
+''');
+  }
+
+  test_createEdits_removeHide_multipleCombinators() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A, B, C hide A, B, C;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['B'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide A, C hide A, C;
+''');
+  }
+
+  test_createEdits_removeHide_multipleNames() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A, B, C hide D, E, F hide G, H, I;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A', 'E', 'I'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide B, C hide D, F hide G, H;
+''');
+  }
+
+  test_createEdits_removeHideCombinator_first() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A hide B hide C;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide B hide C;
+''');
+  }
+
+  test_createEdits_removeHideCombinator_last() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A hide B hide C;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['C'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide A hide B;
+''');
+  }
 
-main() {}
-""");
+  test_createEdits_removeHideCombinator_middle() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A hide B hide C;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['B'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart' hide A hide C;
+''');
   }
 
-  test_none_none() {
-    List<ImportedElements> elements = <ImportedElements>[];
-    List<SourceEdit> edits = _computeEditsFor(elements);
-    expect(edits, hasLength(0));
+  test_createEdits_removeHideCombinator_only() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart';
+''');
   }
 
-  List<SourceEdit> _computeEditsFor(List<ImportedElements> elements) {
-    ImportElementsComputer computer =
-        new ImportElementsComputer(result, targetPath, elements);
-    return computer.compute();
+  test_createEdits_removeHideCombinator_only_multiple() async {
+    Source fooSource = addPackageSource('pkg', 'foo.dart', '');
+    await createBuilder('''
+import 'package:pkg/foo.dart' hide A, B;
+''');
+    await computeChanges(<ImportedElements>[
+      new ImportedElements(fooSource.fullName, '', <String>['A', 'B'])
+    ]);
+    assertChanges('''
+import 'package:pkg/foo.dart';
+''');
   }
 }