cache import suggestions

pkg/analysis_server/test/services/completion/imported_computer_test.dart

Index: pkg/analysis_server/test/services/completion/imported_computer_test.dart
diff --git a/pkg/analysis_server/test/services/completion/imported_computer_test.dart b/pkg/analysis_server/test/services/completion/imported_computer_test.dart
index 80b23678e0e0871dc3dccc64b8db0458816aa94a..6c5e95444c77a6df95a8c2b32c64aa8e95975729 100644
--- a/pkg/analysis_server/test/services/completion/imported_computer_test.dart
+++ b/pkg/analysis_server/test/services/completion/imported_computer_test.dart
@@ -9,6 +9,9 @@ import 'package:unittest/unittest.dart';
 
 import '../../reflective_tests.dart';
 import 'completion_test_util.dart';
+import 'package:analysis_server/src/protocol.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
 
 main() {
   groupSep = ' | ';
@@ -19,8 +22,67 @@ main() {
 class ImportedTypeComputerTest extends AbstractSelectorSuggestionTest {
 
   @override
-  void setUp() {
-    super.setUp();
+  void setUpComputer() {
     computer = new ImportedComputer();
   }
+
+  /**
+   * Assert that the ImportedComputer uses cached results to produce identical
+   * suggestions to the original set of suggestions.
+   */
+  void assertCachedCompute(_) {
+    expect(request.unit.element, isNotNull);
+    List<CompletionSuggestion> oldSuggestions = request.suggestions;
+    /*
+     * Simulate a source change to flush the cached compilation unit
+     */
+    ChangeSet changes = new ChangeSet();
+    changes.addedSource(testSource);
+    context.applyChanges(changes);
+    /*
+     * Calculate a new completion at the same location
+     */
+    setUpComputer();
+    request = new DartCompletionRequest(
+        context,
+        searchEngine,
+        testSource,
+        completionOffset,
+        cache);
+    expect(computeFast(), isTrue);
+    expect(request.unit.element, isNull);
+    List<CompletionSuggestion> newSuggestions = request.suggestions;
+    expect(newSuggestions.length, oldSuggestions.length);
+    oldSuggestions.forEach((CompletionSuggestion s) {
+      expect(newSuggestions.contains(s), isTrue);
+    });
+  }
+
+  @override
+  test_ArgumentList() {
+    return super.test_ArgumentList().then((_) {
+      expect(request.cache.importKey, "import '/libA.dart';");
+    });
+  }
+
+  @override
+  test_ArgumentList_imported_function() {
+    return super.test_ArgumentList_imported_function().then((_) {
+      expect(request.cache.importKey, "import '/libA.dart';");
+    });
+  }
+
+  @override
+  test_AssignmentExpression_RHS() {
+    return super.test_AssignmentExpression_RHS().then((_) {
+      expect(request.cache.importKey, '');
+    });
+  }
+
+  @override
+  test_Block() {
+    return super.test_Block().then((_) {
+      expect(request.cache.importKey, 'import "/testAB.dart";import "/testCD.dart" hide D;import "/testEEF.dart" show EE;import "/testG.dart" as g;');
+    });
+  }
 }