Create a wrapper class to handle CompilerOptions in a uniform way.

pkg/front_end/test/src/base/processed_options_test.dart

+// Copyright (c) 2017, 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.
+
+import 'package:front_end/compiler_options.dart';
+import 'package:front_end/memory_file_system.dart';
+import 'package:front_end/src/base/processed_options.dart';
+import 'package:path/path.dart' as pathos;
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(ProcessedOptionsTest);
+  });
+}
+
+@reflectiveTest
+class ProcessedOptionsTest {
+  final fileSystem = new MemoryFileSystem(pathos.posix, '/');
+
+  test_compileSdk_false() {
+    for (var value in [false, true]) {
+      var raw = new CompilerOptions()..compileSdk = value;
+      var processed = new ProcessedOptions(raw);
+      expect(processed.compileSdk, value);
+    }
+  }
+
+  test_fileSystem_noBazelRoots() {
+    // When no bazel roots are specified, the filesystem should be passed
+    // through unmodified.
+    var raw = new CompilerOptions()..fileSystem = fileSystem;
+    var processed = new ProcessedOptions(raw);
+    expect(processed.fileSystem, same(fileSystem));
+  }
+
+  test_getUriResolver_explicitPackagesFile() async {
+    // This .packages file should be ignored.
+    fileSystem.entityForPath('/.packages').writeAsStringSync('foo:bar\n');
+    // This one should be used.
+    fileSystem
+        .entityForPath('/explicit.packages')
+        .writeAsStringSync('foo:baz\n');
+    var raw = new CompilerOptions()
+      ..fileSystem = fileSystem
+      ..packagesFilePath = '/explicit.packages';
+    var processed = new ProcessedOptions(raw);
+    var uriResolver = await processed.getUriResolver();
+    expect(uriResolver.packages, {'foo': Uri.parse('file:///baz/')});
+    expect(uriResolver.pathContext, same(fileSystem.context));
+  }
+
+  test_getUriResolver_explicitPackagesFile_withBaseLocation() async {
+    // This .packages file should be ignored.
+    fileSystem.entityForPath('/.packages').writeAsStringSync('foo:bar\n');
+    // This one should be used.
+    fileSystem
+        .entityForPath('/base/location/explicit.packages')
+        .writeAsStringSync('foo:baz\n');
+    var raw = new CompilerOptions()
+      ..fileSystem = fileSystem
+      ..packagesFilePath = '/base/location/explicit.packages';
+    var processed = new ProcessedOptions(raw);
+    var uriResolver = await processed.getUriResolver();
+    expect(
+        uriResolver.packages, {'foo': Uri.parse('file:///base/location/baz/')});
+    expect(uriResolver.pathContext, same(fileSystem.context));
+  }
+
+  test_getUriResolver_noPackages() async {
+    // .packages file should be ignored.
+    fileSystem.entityForPath('/.packages').writeAsStringSync('foo:bar\n');
+    var raw = new CompilerOptions()
+      ..fileSystem = fileSystem
+      ..packagesFilePath = '';
+    var processed = new ProcessedOptions(raw);
+    var uriResolver = await processed.getUriResolver();
+    expect(uriResolver.packages, isEmpty);
+    expect(uriResolver.pathContext, same(fileSystem.context));
+  }
+}