Reset AnalysisDriver after changes.

pkg/analyzer/test/src/context/context_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.src.context.context_test;
 
 import 'dart:async';
 
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/cancelable_future.dart';
@@ skipping 1789 matching lines @@
     _removeSource(libBSource);
     _analyzeAll_assertFinished();
     expect(
         context.getResolvedCompilationUnit2(libASource, libASource), isNotNull,
         reason: "libA resolved 2");
     expect(_hasAnalysisErrorWithErrorSeverity(context.getErrors(libASource)),
         isTrue,
         reason: "libA has an error");
   }
 
+  void test_performAnalysisTask_interruptBy_setContents() {
+    Source sourceA = addSource(
+        "/a.dart",
+        r'''
+library expectedToFindSemicolon
+''');
+    // Analyze to the point where some of the results stop depending on
+    // the source content.
+    LibrarySpecificUnit unitA = new LibrarySpecificUnit(sourceA, sourceA);
+    for (int i = 0; i < 10000; i++) {
+      context.performAnalysisTask();
+      if (context.getResult(unitA, RESOLVED_UNIT2) != null) {
+        break;
+      }
+    }
+    // Update the source.
+    // This should invalidate all the results and also reset the driver.
+    context.setContents(sourceA, "library semicolonWasAdded;");
+    expect(context.getResult(unitA, RESOLVED_UNIT2), isNull);
+    expect(analysisDriver.currentWorkOrder, isNull);
+    // Continue analysis.
+    _analyzeAll_assertFinished();
+    expect(context.getErrors(sourceA).errors, isEmpty);
+  }
+
   void test_performAnalysisTask_IOException() {
     TestSource source = _addSourceWithException2("/test.dart", "library test;");
     source.generateExceptionOnRead = false;
     _analyzeAll_assertFinished();
     expect(source.readCount, 2);
     _changeSource(source, "");
     source.generateExceptionOnRead = true;
     _analyzeAll_assertFinished();
     if (AnalysisEngine.instance.limitInvalidationInTaskModel) {
       expect(source.readCount, 7);
@@ skipping 741 matching lines @@
   }
 }
 
 class _AnalysisContextImplTest_test_applyChanges_removeContainer
     implements SourceContainer {
   Source libB;
   _AnalysisContextImplTest_test_applyChanges_removeContainer(this.libB);
   @override
   bool contains(Source source) => source == libB;
 }