Adds support for layout tests.

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
diff --git a/tools/testing/dart/test_suite.dart b/tools/testing/dart/test_suite.dart
index 5eabfd167a912a7af096b24046eb9d89fe4b7bdd..0eef6a926ffa4b30a7253054fa80ed295a22acd4 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -519,6 +519,7 @@ class StandardTestSuite implements TestSuite {
     String filename = info.filename;
     if (optionsFromFile['isMultitest']) return;
     bool isWebTest = optionsFromFile['containsDomImport'];
+    List<String> webTestOutput = optionsFromFile['webTestOutput'];
     bool isLibraryDefinition = optionsFromFile['isLibraryDefinition'];
     if (!isLibraryDefinition && optionsFromFile['containsSourceOrImport']) {
       print('Warning for $filename: Browser tests require #library '
@@ -556,14 +557,14 @@ class StandardTestSuite implements TestSuite {
           dartLibraryFilename = 'test_as_library.dart';
           File file = new File('$tempDir/$dartLibraryFilename');
           RandomAccessFile dartLibrary = file.openSync(FileMode.WRITE);
-          dartLibrary.writeStringSync(WrapDartTestInLibrary(testPath));
+          dartLibrary.writeStringSync(wrapDartTestInLibrary(testPath));
           dartLibrary.closeSync();
         }
 
         File file = new File(dartWrapperFilename);
         RandomAccessFile dartWrapper = file.openSync(FileMode.WRITE);
         dartWrapper.writeStringSync(
-            DartTestWrapper(dartDir, dartLibraryFilename));
+            dartTestWrapper(dartDir, dartLibraryFilename));
         dartWrapper.closeSync();
       } else {
         dartWrapperFilename = testPath;
@@ -591,11 +592,17 @@ class StandardTestSuite implements TestSuite {
         // with 'C:' adding 'file:///' solves the problem.
         filePrefix = 'file:///';
       }
-      htmlTest.writeStringSync(GetHtmlContents(
+      String content;
+      if (webTestOutput.isEmpty()) {
+        content = getHtmlContents(
           filename,
           '$filePrefix$dartDir/lib/unittest/test_controller.js',
           scriptType,
-          '$filePrefix$scriptPath'));
+          '$filePrefix$scriptPath');
+      } else {
+        content = getHtmlLayoutContents(scriptType, '$filePrefix$scriptPath');
+      }
+      htmlTest.writeStringSync(content);
       htmlTest.closeSync();
 
       // Construct the command(s) that compile all the inputs needed by the
@@ -609,14 +616,13 @@ class StandardTestSuite implements TestSuite {
         // some tests require compiling multiple input scripts.
         List<String> otherScripts = optionsFromFile['otherScripts'];
         for (String name in otherScripts) {
-          int end = filename.lastIndexOf('/');
-          if (end == -1) {
+          String dir = _dirNameFromFile(filename);
+          if (dir == null) {
             print('Warning: error processing "OtherScripts" of $filename.');
             print('Skipping test ($testName).');
             return;
           }
-          String dir = filename.substring(0, end);
-          end = name.lastIndexOf('.dart');
+          int end = name.lastIndexOf('.dart');
           if (end == -1) {
             print('Warning: error processing "OtherScripts" in $filename.');
             print('Skipping test ($testName).');
@@ -656,6 +662,10 @@ class StandardTestSuite implements TestSuite {
           args.add('--dart-flags=${Strings.join(dartFlags, " ")}');
         }
         args.add(htmlPath);
+        if (!webTestOutput.isEmpty()) {
+          String dir = _dirNameFromFile(filename);
+          args.add('--out-expectation=$dir/${webTestOutput[0]}');
+        }
       }
       commands.add(new Command('python', args));
 
@@ -667,6 +677,11 @@ class StandardTestSuite implements TestSuite {
     }
   }
 
+  String _dirNameFromFile(String filename) {
+    int end = filename.lastIndexOf('/');
+    return (end == -1) ? null : filename.substring(0, end);
+  }
+
   /** Helper to create a compilation command for a single input file. */
   Command _compileCommand(String inputFile, String outputFile,
       String compiler, String dir, var vmOptions) {
@@ -852,10 +867,57 @@ class StandardTestSuite implements TestSuite {
     return result;
   }
 
+  /**
+   * Special options for individual tests are specified with comments directly
+   * in test files. Here is a list of parameters available:
+   *   - Flags can be passed to the vm or dartium process that runs the test as
+   *   follows:
+   *
+   *     // VMOptions=--flag1 --flag2
+   *
+   *   - Flags can be passed to the dart script that contains the test as
+   *   follows:
+   *
+   *     // DartOptions=--flag1 --flag2
+   *
+   *   - For tests that depend on compiling other files with dart2js (e.g.
+   *   isolate tests that use multiple source scripts), you can specify
+   *   additional files to compile as follows:
+   *
+   *     // OtherScripts=file1.dart file2.dart
+   *
+   *   - You can indicate whether a test is treated as a web-only test as
+   *   follows:
+   *
+   *     // WebTest=true

[Siggi Cherem (dart-lang), 2012/06/27 01:50:42]

this is something I'm adding on a separate CL
(https://chromiumcodereview.appspot.com//10685009), but I went ahead and started
writing the documentation right away assuming I'll submit this on a second step.

+   *
+   *   Most tests are not web tests, but can (and will be) wrapped within
+   *   another script file to test them also on browser environments (e.g.
+   *   language and corelib tests are run this way). Specifing this flag means
+   *   that no wrapping is necessary.
+   *
+   *   - Using test expectations for layout tests:
+   *
+   *     // WebTestOutput=expected_file.txt
+   *          or
+   *     // WebTestOutput=expected_file.png
+   *
+   *   By default tests are run without expectation files: test.dart assumes

[Bill Hesse, 2012/06/27 09:24:37]

Say "web tests" here, not just "tests".  This only applies to browser tests,
right?

[Siggi Cherem (dart-lang), 2012/06/27 20:21:05]

Done.

+   *   tests fail if the process return a non-zero exit code (in the case of web
+   *   tests, we check for PASS/FAIL indications in the test output). Specifying
+   *   a test output explicitly will check that the test output matches that
+   *   specified in the expectation file. In particular, the output of a web
+   *   test will be a rendering representation (either in text form if the
+   *   expectation ends in .txt, or an image, if the expectation ends in .png).
+   *   These expectations can be recorded for the first time by specifying the
+   *   option above, running the test, and running the copy command printed by
+   *   the test script.
+   */
   Map readOptionsFromFile(String filename) {
     RegExp testOptionsRegExp = const RegExp(@"// VMOptions=(.*)");
     RegExp dartOptionsRegExp = const RegExp(@"// DartOptions=(.*)");
     RegExp otherScriptsRegExp = const RegExp(@"// OtherScripts=(.*)");
+    RegExp testOutputRegExp = const RegExp(@"// WebTestOutput=(.*)");
     RegExp multiTestRegExp = const RegExp(@"/// [0-9][0-9]:(.*)");
     RegExp staticTypeRegExp =
         const RegExp(@"/// ([0-9][0-9]:){0,1}\s*static type warning");
@@ -915,10 +977,12 @@ class StandardTestSuite implements TestSuite {
       isStaticClean = true;
     }
 
-    List<String> otherScripts = new List<String>();
-    matches = otherScriptsRegExp.allMatches(contents);
-    for (var match in matches) {
-      otherScripts.addAll(match[1].split(' ').filter((e) => e != ''));
+    List<String> otherScripts = _readListOption(otherScriptsRegExp, contents);
+    List<String> webTestOutput = _readListOption(testOutputRegExp, contents);
+    if (!webTestOutput.isEmpty() && webTestOutput.length > 1) {
+        throw new Exception(
+            'Please use a single expected output for '
+            '"// WebTestOutput=" in $filename');
     }
 
     if (contents.contains("@compile-error")) {
@@ -954,12 +1018,21 @@ class StandardTestSuite implements TestSuite {
              "containsLeadingHash": containsLeadingHash,
              "isolateStubs": isolateStubs,
              "containsDomImport": containsDomImport,
+             "webTestOutput": webTestOutput,
              "isLibraryDefinition": isLibraryDefinition,
              "containsSourceOrImport": containsSourceOrImport,
              "numStaticTypeAnnotations": numStaticTypeAnnotations,
              "numCompileTimeAnnotations": numCompileTimeAnnotations};
   }
 
+  static List<String> _readListOption(RegExp matcher, String contents) {
+    List<String> res = new List<String>();
+    for (var match in matcher.allMatches(contents)) {
+      res.addAll(match[1].split(' ').filter((e) => e != ''));
+    }
+    return res;
+  }
+
   List<List<String>> getVmOptions(Map optionsFromFile) {
     if (configuration['compiler'] == 'dart2js') {
       return [[]];