Gracefully handle IO exceptions while resolving URIs (issue 23023)

pkg/analyzer/test/generated/engine_test.dart

Index: pkg/analyzer/test/generated/engine_test.dart
diff --git a/pkg/analyzer/test/generated/engine_test.dart b/pkg/analyzer/test/generated/engine_test.dart
index 52b8c4026a27a86cb7d29184960b021f504972b3..df19bde330befd044a10459e8513894cd2f9d4bd 100644
--- a/pkg/analyzer/test/generated/engine_test.dart
+++ b/pkg/analyzer/test/generated/engine_test.dart
@@ -4539,6 +4539,13 @@ class LintGeneratorTest_Linter_Null_Visitor extends Linter {
   AstVisitor getVisitor() => null;
 }
 
+class MockSourceFactory extends SourceFactory {
+  MockSourceFactory() : super([]);
+  Source resolveUri(Source containingSource, String containedUri) {
+    throw new JavaIOException();
+  }
+}
+
 @reflectiveTest
 class ParseDartTaskTest extends EngineTestCase {
   void test_accept() {
@@ -4627,6 +4634,26 @@ class A {}''';
         new ParseDartTaskTestTV_perform_validateDirectives(context, source));
   }
 
+  void test_resolveDirective_dartUri() {
+    GatheringErrorListener listener = new GatheringErrorListener();
+    ImportDirective directive = AstFactory.importDirective3('dart:core', null);
+    AnalysisContext context = AnalysisContextFactory.contextWithCore();
+    Source source =
+        ParseDartTask.resolveDirective(context, null, directive, listener);
+    expect(source, isNotNull);
+  }
+
+  void test_resolveDirective_exception() {
+    GatheringErrorListener listener = new GatheringErrorListener();
+    ImportDirective directive = AstFactory.importDirective3('dart:core', null);
+    AnalysisContext context = new AnalysisContextImpl();
+    context.sourceFactory = new MockSourceFactory();
+    Source source =
+        ParseDartTask.resolveDirective(context, null, directive, listener);
+    expect(source, isNull);
+    expect(listener.errors.length, 1);

[scheglov, 2015/03/27 23:05:58]

expect(listener.errors, hasLength(1));

[Brian Wilkerson, 2015/03/27 23:51:57]

Done

+  }
+
   /**
    * Create and return a task that will parse the given content from the given source in the given
    * context.