Fix build - create output dir if needed

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 74 matching lines @@
   }
 
   bool compile(BatchCompiler compiler, String filePath) {
     compiler.compileFromUriString(filePath, (String url) {
       // Write compiler messages to disk.
       var messagePath = '${path.withoutExtension(url)}.txt';
       var file = new File(messagePath);
       var message = '''
 // Messages from compiling ${path.basenameWithoutExtension(url)}.dart
 $compilerMessages''';
+      var dir = file.parent;
+      if (!dir.existsSync()) dir.createSync(recursive: true);
       file.writeAsStringSync(message);
       compilerMessages.clear();
     });
     return !compiler.failure;
   }
 
   var multitests = new Set<String>();
   {
     // Expand wacky multitests into a bunch of test files.
     // We'll compile each one as if it was an input.
@@ skipping 20 matching lines @@
     }
   }
 
   var batchCompiler = createCompiler(realSdkContext);
 
   for (var dir in [null, 'language']) {
     if (codeCoverage && dir == 'language') continue;
 
     group('dartdevc ' + path.join('test', 'codegen', dir), () {
       var outDir = new Directory(path.join(expectDir, dir));
       if (!outDir.existsSync()) outDir.createSync(recursive: true);

[Jennifer Messerly, 2015/10/03 00:23:02]

hmm, shouldn't this line do what we need?

ideally we could consolidate these checks. Maybe it's the compiler's
responsibility to create the output directory.

 
       var testFiles = _findTests(path.join(inputDir, dir), filePattern);
       for (var filePath in testFiles) {
         if (multitests.contains(filePath)) continue;
 
         var filename = path.basenameWithoutExtension(filePath);
 
         test('$filename.dart', () {
           // TODO(jmesserly): this was added to get some coverage of source maps
           // and closure annotations.
@@ skipping 95 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) {}
 }