Issue 27358. Reset AnalysisContext 'sourceFactory' and 'typeSystem' on analysis options change.

pkg/analysis_server/test/context_manager_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.context.directory.manager;
 
 import 'dart:collection';
 import 'dart:io' as io;
 
 import 'package:analysis_server/src/context_manager.dart';
@@ skipping 2317 matching lines @@
 #  errors:
 #    unused_local_variable: ignore
 ''');
     // Setup context.
     manager.setRoots(<String>[projPath], <String>[], <String, String>{});
 
     // Verify filter setup.
     expect(errorProcessors, isEmpty);
   }
 
+  test_optionsFile_update_strongMode() async {
+    var file = resourceProvider.newFile(
+        '$projPath/bin/test.dart',
+        r'''
+main() {
+  var paths = <int>[];
+  var names = <String>[];
+  paths.addAll(names.map((s) => s.length));
+}
+''');
+    resourceProvider.newFile(
+        '$projPath/$optionsFileName',
+        r'''
+analyzer:
+  strong-mode: false
+''');
+    // Create the context.
+    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
+    await pumpEventQueue();
+
+    AnalysisContext context = manager.getContextFor(projPath);
+    Source testSource = context.getSourcesWithFullName(file.path).single;
+
+    // Not strong mode - both in the context and the SDK context.
+    {
+      AnalysisContext sdkContext = context.sourceFactory.dartSdk.context;
+      expect(context.analysisOptions.strongMode, isFalse);
+      expect(sdkContext.analysisOptions.strongMode, isFalse);
+      expect(context.computeErrors(testSource), isEmpty);
+    }
+
+    // Update the options file - turn on 'strong-mode'.
+    resourceProvider.updateFile(
+        '$projPath/$optionsFileName',
+        r'''
+analyzer:
+  strong-mode: true
+''');
+    await pumpEventQueue();
+
+    // Strong mode - both in the context and the SDK context.
+    {
+      AnalysisContext context = manager.getContextFor(projPath);
+      AnalysisContext sdkContext = context.sourceFactory.dartSdk.context;
+      expect(context.analysisOptions.strongMode, isTrue);
+      expect(sdkContext.analysisOptions.strongMode, isTrue);
+      // The code is strong-mode clean.
+      // Verify that TypeSystem was reset.
+      expect(context.computeErrors(testSource), isEmpty);
+    }
+  }
+
   test_path_filter_analysis_option() async {
     // Create files.
     String libPath = newFolder([projPath, ContextManagerTest.LIB_NAME]);
     newFile([libPath, 'main.dart']);
     newFile([libPath, 'nope.dart']);
     String sdkExtPath = newFolder([projPath, 'sdk_ext']);
     newFile([sdkExtPath, 'entry.dart']);
     String sdkExtSrcPath = newFolder([projPath, 'sdk_ext', 'src']);
     newFile([sdkExtSrcPath, 'part.dart']);
     // Setup analysis options file with ignore list.
@@ skipping 366 matching lines @@
 class TestUriResolver extends UriResolver {
   Map<Uri, Source> uriMap;
 
   TestUriResolver(this.uriMap);
 
   @override
   Source resolveAbsolute(Uri uri, [Uri actualUri]) {
     return uriMap[uri];
   }
 }