Suppress scanner errors for non-existent URIs.

pkg/analysis_server/test/analysis/notification_errors_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.analysis.notification_errors;
 
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analysis_server/src/protocol.dart';
+import 'package:analyzer/src/generated/engine.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart';
 
 import '../analysis_abstract.dart';
 import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
   defineReflectiveTests(NotificationErrorsTest);
 }
 
 @reflectiveTest
 class NotificationErrorsTest extends AbstractAnalysisTest {
   Map<String, List<AnalysisError>> filesErrors = {};
 
   void processNotification(Notification notification) {
     if (notification.event == ANALYSIS_ERRORS) {
       var decoded = new AnalysisErrorsParams.fromNotification(notification);
       filesErrors[decoded.file] = decoded.errors;
     }
   }
 
   @override
   void setUp() {
     super.setUp();
     server.handlers = [new AnalysisDomainHandler(server),];
   }
 
+  test_importError() {
+    createProject();
+
+    addTestFile('''
+import 'does_not_exist.dart';
+''');
+    return waitForTasksFinished().then((_) {
+      List<AnalysisError> errors = filesErrors[testFile];
+      // Verify that we are generating only 1 error for the bad URI.
+      // https://github.com/dart-lang/sdk/issues/23754
+      expect(errors, hasLength(1));
+      AnalysisError error = errors[0];
+      expect(error.severity, AnalysisErrorSeverity.ERROR);
+      expect(error.type, AnalysisErrorType.COMPILE_TIME_ERROR);
+      expect(error.message, startsWith('Target of URI does not exist'));
+    });
+  }
+
   test_notInAnalysisRoot() {
     createProject();
     String otherFile = '/other.dart';
     addFile(otherFile, 'UnknownType V;');
     addTestFile('''
 import '/other.dart';
 
 main() {
   print(V);
 }
@@ skipping 28 matching lines @@
 ''');
     return waitForTasksFinished().then((_) {
       List<AnalysisError> errors = filesErrors[testFile];
       expect(errors, hasLength(1));
       AnalysisError error = errors[0];
       expect(error.severity, AnalysisErrorSeverity.WARNING);
       expect(error.type, AnalysisErrorType.STATIC_WARNING);
     });
   }
 }