abort completion request - fixes #24271

pkg/analysis_server/test/domain_completion_test.dart

 // Copyright (c) 2014, 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.
 
 library test.domain.completion;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/domain_completion.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart';
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/services/completion/dart/completion_manager.dart';
 import 'package:analysis_server/src/services/completion/dart/contribution_sorter.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart';
 
 import 'analysis_abstract.dart';
 import 'domain_completion_util.dart';
+import 'mocks.dart' show pumpEventQueue;
 import 'utils.dart';
 
 main() {
   initializeTestEnvironment();
   defineReflectiveTests(CompletionDomainHandlerTest);
   defineReflectiveTests(_NoSearchEngine);
 }
 
 @reflectiveTest
 class CompletionDomainHandlerTest extends AbstractCompletionDomainTest {
@@ skipping 16 matching lines @@
     ''');
     return getSuggestions().then((_) {
       expect(replacementOffset, equals(completionOffset));
       expect(replacementLength, equals(0));
       assertHasResult(CompletionSuggestionKind.INVOCATION, 'Object');
       assertHasResult(CompletionSuggestionKind.INVOCATION, 'HtmlElement');
       assertNoResult('test');
     });
   }
 
+  test_imports_aborted_new_request() async {
+    addTestFile('''
+        class foo { }
+        c^''');
+
+    // Make a request for suggestions
+    Request request =
+        new CompletionGetSuggestionsParams(testFile, completionOffset)
+            .toRequest('7');
+    Response response = handleSuccessfulRequest(request);
+    var result1 = new CompletionGetSuggestionsResult.fromResponse(response);
+    var completionId1 = result1.id;
+    assertValidId(response.id);
+
+    // Perform some analysis but assert that no suggestions have yet been made
+    completionId = completionId1;
+    await pumpEventQueue(25);
+    expect(suggestionsDone, isFalse);
+    expect(suggestions, hasLength(0));
+
+    // Make another request before the first request completes
+    Request request2 =
+        new CompletionGetSuggestionsParams(testFile, completionOffset)
+            .toRequest('8');
+    Response response2 = handleSuccessfulRequest(request2);
+    var result2 = new CompletionGetSuggestionsResult.fromResponse(response2);
+    var completionId2 = result2.id;
+    assertValidId(completionId2);
+
+    // Wait for both sets of suggestions
+    completionId = completionId2;
+    await pumpEventQueue();
+    expect(allSuggestions[completionId1], hasLength(0));
+    expect(allSuggestions[completionId2], same(suggestions));
+    assertHasResult(CompletionSuggestionKind.KEYWORD, 'class',
+        relevance: DART_RELEVANCE_HIGH);
+  }
+
+  test_imports_aborted_source_changed() async {
+    addTestFile('''
+        class foo { }
+        c^''');
+
+    // Make a request for suggestions
+    Request request =
+        new CompletionGetSuggestionsParams(testFile, completionOffset)
+            .toRequest('0');
+    Response response = handleSuccessfulRequest(request);
+    completionId = response.id;
+    assertValidId(completionId);
+
+    // Perform some analysis but assert that no suggestions have yet been made
+    await pumpEventQueue(25);
+    expect(suggestionsDone, isFalse);
+    expect(suggestions, hasLength(0));
+
+    // Simulate user deleting text after request but before suggestions returned
+    server.updateContent('uc1', {testFile: new AddContentOverlay(testCode)});
+    server.updateContent('uc2', {
+      testFile: new ChangeContentOverlay(
+          [new SourceEdit(completionOffset - 1, 1, '')])
+    });
+
+    // Expect the completion domain to discard request because source changed
+    await pumpEventQueue().then((_) {
+      expect(suggestionsDone, isTrue);
+    });
+    expect(suggestions, hasLength(0));
+  }
+
   test_imports_incremental() async {
     addTestFile('''library foo;
       e^
       import "dart:async";
       import "package:foo/foo.dart";
       class foo { }''');
     await waitForTasksFinished();
     server.updateContent('uc1', {testFile: new AddContentOverlay(testCode)});
     server.updateContent('uc2', {
       testFile:
@@ skipping 406 matching lines @@
 }
     ''');
     await waitForTasksFinished();
     Request request =
         new CompletionGetSuggestionsParams(testFile, 0).toRequest('0');
     Response response = handler.handleRequest(request);
     expect(response.error, isNotNull);
     expect(response.error.code, RequestErrorCode.NO_INDEX_GENERATED);
   }
 }