In URI resolution tests, don't access the local filesystem.

pkg/analyzer/test/generated/all_the_rest_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 analyzer.test.generated.all_the_rest_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
@@ skipping 46 matching lines @@
   runReflectiveTests(ErrorSeverityTest);
   runReflectiveTests(ExitDetectorTest);
   runReflectiveTests(ExitDetectorTest2);
   runReflectiveTests(FileBasedSourceTest);
   runReflectiveTests(ResolveRelativeUriTest);
   // ignore: deprecated_member_use
   runReflectiveTests(SDKLibrariesReaderTest);
   runReflectiveTests(UriKindTest);
 }
 
+/**
+ * Create a tiny mock SDK for use in URI resolution tests.
+ */
+DartSdk _createSdk() {
+  MemoryResourceProvider resourceProvider = new MemoryResourceProvider();
+  String sdkFolderName =
+      resourceProvider.pathContext.separator == '/' ? '/sdk' : r'C:\sdk';
+  Folder sdkFolder = resourceProvider.newFolder(sdkFolderName);
+  expect(sdkFolder, isNotNull);
+  resourceProvider.newFile(
+      resourceProvider.pathContext.join(sdkFolderName, 'lib', '_internal',
+          'sdk_library_metadata', 'lib', 'libraries.dart'),
+      '''
+const Map<String, LibraryInfo> libraries = const {
+  "core": const LibraryInfo("core/core.dart")
+};
+''');
+  resourceProvider.newFile(
+      resourceProvider.pathContext
+          .join(sdkFolderName, 'lib', 'core', 'core.dart'),
+      '''
+library dart.core;
+''');
+  return new FolderBasedDartSdk(resourceProvider, sdkFolder);
+}
+
 @reflectiveTest
 class ContentCacheTest {
   void test_setContents() {
     Source source = new TestSource();
     ContentCache cache = new ContentCache();
     expect(cache.getContents(source), isNull);
     expect(cache.getModificationStamp(source), isNull);
     String contents = "library lib;";
     expect(cache.setContents(source, contents), isNull);
     expect(cache.getContents(source), contents);
     expect(cache.getModificationStamp(source), isNotNull);
     expect(cache.setContents(source, contents), contents);
     expect(cache.setContents(source, null), contents);
     expect(cache.getContents(source), isNull);
     expect(cache.getModificationStamp(source), isNull);
     expect(cache.setContents(source, null), isNull);
   }
 }
 
 @reflectiveTest
 class CustomUriResolverTest {
   void test_creation() {
     expect(new CustomUriResolver({}), isNotNull);
   }
 
   void test_resolve_unknown_uri() {
-    UriResolver resolver = new CustomUriResolver({
-      'custom:library': '/path/to/library.dart',
-    });
+    UriResolver resolver =
+        new CustomUriResolver({'custom:library': '/path/to/library.dart',});
     Source result =
         resolver.resolveAbsolute(parseUriWithException("custom:non_library"));
     expect(result, isNull);
   }
 
   void test_resolve_uri() {
     String path =
         FileUtilities2.createFile("/path/to/library.dart").getAbsolutePath();
-    UriResolver resolver = new CustomUriResolver({
-      'custom:library': path,
-    });
+    UriResolver resolver = new CustomUriResolver({'custom:library': path,});
     Source result =
         resolver.resolveAbsolute(parseUriWithException("custom:library"));
     expect(result, isNotNull);
     expect(result.fullName, path);
   }
 }
 
 @reflectiveTest
 class DartUriResolverTest {
   void test_creation() {
@@ skipping 22 matching lines @@
     expect(result, isNull);
   }
 
   void test_resolve_nonDart() {
     DartSdk sdk = _createSdk();
     UriResolver resolver = new DartUriResolver(sdk);
     Source result = resolver
         .resolveAbsolute(parseUriWithException("package:some/file.dart"));
     expect(result, isNull);
   }
-
-  DartSdk _createSdk() {
-    ResourceProvider resourceProvider = PhysicalResourceProvider.INSTANCE;
-    Folder sdkFolder = FolderBasedDartSdk.defaultSdkDirectory(resourceProvider);
-    expect(sdkFolder, isNotNull);
-    return new FolderBasedDartSdk(resourceProvider, sdkFolder);
-  }
 }
 
 @deprecated
 @reflectiveTest
 class DirectoryBasedDartSdkTest {
   void fail_getDocFileFor() {
     DirectoryBasedDartSdk sdk = _createDartSdk();
     JavaFile docFile = sdk.getDocFileFor("html");
     expect(docFile, isNotNull);
   }
@@ skipping 4204 matching lines @@
   }
 
   void test_system() {
     JavaFile file = FileUtilities2.createFile("/does/not/exist.dart");
     FileBasedSource source =
         new FileBasedSource(file, parseUriWithException("dart:core"));
     expect(source, isNotNull);
     expect(source.fullName, file.getAbsolutePath());
     expect(source.isInSystemLibrary, isTrue);
   }
-
-  DartSdk _createSdk() {
-    ResourceProvider resourceProvider = PhysicalResourceProvider.INSTANCE;
-    Folder sdkFolder = FolderBasedDartSdk.defaultSdkDirectory(resourceProvider);
-    expect(sdkFolder, isNotNull);
-    return new FolderBasedDartSdk(resourceProvider, sdkFolder);
-  }
 }
 
 @reflectiveTest
 class ResolveRelativeUriTest {
   void test_resolveRelative_dart_dartUri() {
     _assertResolve('dart:foo', 'dart:bar', 'dart:bar');
   }
 
   void test_resolveRelative_dart_fileName() {
     _assertResolve('dart:test', 'lib.dart', 'dart:test/lib.dart');
@@ skipping 126 matching lines @@
     expect(UriKind.fromEncoding(0x70), same(UriKind.PACKAGE_URI));
     expect(UriKind.fromEncoding(0x58), same(null));
   }
 
   void test_getEncoding() {
     expect(UriKind.DART_URI.encoding, 0x64);
     expect(UriKind.FILE_URI.encoding, 0x66);
     expect(UriKind.PACKAGE_URI.encoding, 0x70);
   }
 }