reduce diff churn due to server_mode test

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';
 import 'package:cli_util/cli_util.dart' show getSdkDir;
 import 'package:analyzer/src/generated/engine.dart' show AnalysisEngine, Logger;
 import 'package:analyzer/src/generated/java_engine.dart' show CaughtException;
 import 'package:args/args.dart';
 import 'package:logging/logging.dart' show Level;
 import 'package:path/path.dart' as path;
 import 'package:unittest/unittest.dart';
 
 import 'package:dev_compiler/devc.dart';
 import 'package:dev_compiler/src/options.dart';
 import 'package:dev_compiler/src/dependency_graph.dart'
     show defaultRuntimeFiles;
+import 'package:dev_compiler/src/utils.dart'
+    show computeHash, computeHashFromFile;
+import 'package:html/parser.dart' as html;
 
 final ArgParser argParser = new ArgParser()
   ..addOption('dart-sdk', help: 'Dart SDK Path', defaultsTo: null)
   ..addFlag('dart-gen',
       abbr: 'd', help: 'Generate dart output', defaultsTo: false);
 
 main(arguments) {
   if (arguments == null) arguments = [];
   ArgResults args = argParser.parse(arguments);
   var script = Platform.script.path;
@@ skipping 187 matching lines @@
 
       var result =
           compile(filePath, realSdk, serverMode: true, subDir: 'server_mode');
       var success = !result.failure;
 
       // Write compiler messages to disk.
       new File(path.join(actualDir, 'server_mode', 'html_input.txt'))
           .writeAsStringSync(compilerMessages.toString());
 
       var expectedFiles = [
-        'html_input.html',
         'dir/html_input_a.js',
         'dir/html_input_b.js',
         'dir/html_input_c.js',
         'dir/html_input_d.js',
         'dir/html_input_e.js',
         'dev_compiler/runtime/messages_widget.js',
         'dev_compiler/runtime/messages.css'
       ]..addAll(expectedRuntime);
 
+      // Parse the HTML file and verify its contents were expected.
+      var htmlPath = path.join(actualDir, 'server_mode', 'html_input.html');
+      var doc = html.parse(new File(htmlPath).readAsStringSync());
+
       for (var filepath in expectedFiles) {
-        var outFile = new File(path.join(actualDir, 'server_mode', filepath));
-        expect(outFile.existsSync(), success,
-            reason: '${outFile.path} was created iff compilation succeeds');
+        var outPath = path.join(actualDir, 'server_mode', filepath);
+        expect(new File(outPath).existsSync(), success,
+            reason: '$outPath was created iff compilation succeeds');
+
+        var query;
+        if (filepath.endsWith('js')) {
+          var hash;
+          if (filepath.startsWith('dev_compiler')) {
+            hash = computeHashFromFile(outPath);
+          } else {
+            // TODO(jmesserly): see if we can get this to return the same
+            // answer as computeHashFromFile.
+            hash = computeHash(new File(outPath).readAsStringSync());
+          }
+          query = 'script[src="cached/$hash/$filepath"]';
+        } else {
+          var hash = computeHashFromFile(outPath);
+          query = 'link[href="cached/$hash/$filepath"]';
+        }
+        expect(doc.querySelector(query), isNotNull,
+            reason: "should find `$query` in $htmlPath for $outPath");
       }
+
+      // Clean up the server mode folder, otherwise it causes diff churn.
+      var dir = new Directory(path.join(actualDir, 'server_mode'));
+      if (dir.existsSync()) dir.deleteSync(recursive: true);

[Siggi Cherem (dart-lang), 2015/04/01 21:28:20]

minor nit: maybe just assert that it exists?

expect(dir.existsSync(), isTrue);
dir.deleteSync...

     });
   }
 }
 
 /// An implementation of analysis engine's [Logger] that prints.
 class PrintLogger implements Logger {
   @override void logError(String message, [CaughtException exception]) {
     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) {}
 }