coverage: increase coverage of js_codegen

test/codegen_test.dart

 // Copyright (c) 2015, 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.
 
 /// Tests code generation.
 /// Runs Dart Dev Compiler on all input in the `codegen` directory and checks
 /// that the output is what we expected.
 library dev_compiler.test.codegen_test;
 
 import 'dart:io';
@@ skipping 39 matching lines @@
       ? path.join(testDir, 'dart_codegen')
       : path.join(testDir, 'codegen');
   var actualDir = path.join(inputDir, 'actual');
   var paths = new Directory(inputDir)
       .listSync()
       .where((f) => f is File)
       .map((f) => f.path)
       .where((p) => p.endsWith('.dart') && filePattern.hasMatch(p));
 
   compile(String entryPoint, String sdkPath,
-      {bool checkSdk: false, bool serverMode: false}) {
+      {bool checkSdk: false, bool serverMode: false, bool sourceMaps: false}) {
+    // TODO(jmesserly): add a way to specify flags in the test file, so
+    // they're more self-contained.
     var options = new CompilerOptions(
         outputDir: serverMode ? path.join(actualDir, 'server_mode') : actualDir,
         useColors: false,
         outputDart: dartGen,
         formatOutput: dartGen,
-        emitSourceMaps: false,
+        emitSourceMaps: sourceMaps,
         forceCompile: checkSdk,
         cheapTestFormat: checkSdk,
         checkSdk: checkSdk,
         entryPointFile: entryPoint,
         dartSdkPath: sdkPath,
         serverMode: serverMode);
     return new Compiler(options).run();
   }
   var realSdk = getSdkDir(arguments).path;
 
   // Validate that old output is gone before running.
   // TODO(jmesserly): it'd be nice to do all cleanup here, including removing
   // pub's 'packages' symlinks which mess up the diff. That way this test
   // can be self contained instead of depending on a shell script.
   if (new Directory(actualDir).existsSync()) {
     throw 'Old compiler output should be cleaned up first. Use ./test/test.sh';
   }
 
   for (var filePath in paths) {
     var filename = path.basenameWithoutExtension(filePath);
 
     test('devc $filename.dart', () {
       compilerMessages.writeln('// Messages from compiling $filename.dart');
 
-      var result = compile(filePath, realSdk);
+      // TODO(jmesserly): this was added to get some coverage of source maps
+      // We need a more comprehensive strategy to test them.

[Siggi Cherem (dart-lang), 2015/03/18 16:16:13]

how about detecting if there is one .map file in the expect folder?

sort of like how we detected if we needed a layout test in the past if there was
a .txt or a .png file with the name of the test next to it.

[Jennifer Messerly, 2015/03/18 16:17:53]

that's a really good idea. I also thought about having a way to specify options
in the test file, so you could pass --source-maps

+      var sourceMaps = filename == 'map_keys';
+      var result = compile(filePath, realSdk, sourceMaps: sourceMaps);
       var success = !result.failure;
 
       // Write compiler messages to disk.
       new File(path.join(actualDir, '$filename.txt'))
           .writeAsStringSync(compilerMessages.toString());
 
       var outFile = dartGen
           ? new File(path.join(actualDir, '$filename/$filename.dart'))
           : new File(path.join(actualDir, '$filename.js'));
       expect(outFile.existsSync(), success,
@@ skipping 116 matching lines @@
     print('[AnalysisEngine] error $message $exception');
   }
 
   @override void logError2(String message, Object exception) {
     print('[AnalysisEngine] error $message $exception');
   }
 
   void logInformation(String message, [CaughtException exception]) {}
   void logInformation2(String message, Object exception) {}
 }