Added support for skipping redundant dart2js compilations.

tests/standalone/io/skipping_dart2js_compilations_test.dart

Index: tests/standalone/io/skipping_dart2js_compilations_test.dart
diff --git a/tests/standalone/io/skipping_dart2js_compilations_test.dart b/tests/standalone/io/skipping_dart2js_compilations_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..d4c111b60503ce8ae6b4485fc6181bc8b6739f00
--- /dev/null
+++ b/tests/standalone/io/skipping_dart2js_compilations_test.dart
@@ -0,0 +1,225 @@
+// Copyright (c) 2012, 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.
+
+/*
+ * This test makes sure that the "skipping Dart2Js compilations if the output is
+ * already up to date" feature does work as it should.
+ * Therefore this test ensures that compilations are only skipped if the last
+ * modified date of the output of a dart2js compilation is newer than
+ *   - the the dart application to compile (including it's dependencies)
+ *   - the dart2js snapshot
+ * Furtheremore it ensure that a compilations is not skipped if any of the
+ * necessary files could not be found (dart2js snapshots, previous dart2js
+ * output (+deps file), dart application)
+ */
+
+import 'dart:io';
+import 'dart:isolate';
+import 'dart:uri';
+import '../../../tools/testing/dart/test_suite.dart' as suite;
+import '../../../tools/testing/dart/test_runner.dart' as runner;
+import '../../../tools/testing/dart/test_options.dart' as options;
+import '../../../tools/testing/dart/status_file_parser.dart' as status;
+
+/**
+ * This class is reponsible for setting up the files necessary for this test
+ * as well as touching a file.
+ */
+class FileUtils {
+  Directory tempDir;
+  File testJs;
+  File testJsDeps;
+  File testDart;
+  File testSnapshot;
+
+  FileUtils({bool createJs,
+             bool createJsDeps,
+             bool createDart,
+             bool createSnapshot}) {
+    tempDir = new Directory('').createTempSync();
+    if (createJs) {
+      testJs = _createFile(testJsFilePath);
+      _writeToFile(testJs, "test.js content");
+    }
+    if (createSnapshot) {
+      testSnapshot = _createFile(testSnapshotFilePath);
+      _writeToFile(testSnapshot, "dart2js snapshot");
+    }
+    if (createDart) {
+      testDart = _createFile(testDartFilePath);
+      _writeToFile(testDart, "dart code");
+    }
+    if (createJsDeps) {
+      testJsDeps = _createFile(testJsDepsFilePath);
+      var path = suite.TestUtils.absolutePath(new Path.fromNative(tempDir.path))
+          .append("test.dart");
+      _writeToFile(testJsDeps, "file://$path");
+    }
+  }
+
+  void cleanup() {
+    if (testJs != null) testJs.deleteSync();
+    if (testJsDeps != null) testJsDeps.deleteSync();
+    if (testDart != null) testDart.deleteSync();
+    if (testSnapshot != null) testSnapshot.deleteSync();
+
+    // if the script did run, it created this file, so we need to delete it
+    File file = new File(scriptOutputPath.toNativePath());
+    if (file.existsSync()) {
+      file.deleteSync();
+    }
+
+    tempDir.deleteSync();
+  }
+
+  Path get scriptOutputPath {
+    return suite.TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('created_if_command_did_run.txt'));
+  }
+
+  Path get testDartFilePath {
+    return suite.TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('test.dart'));
+  }
+
+  Path get testJsFilePath {
+    return suite.TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('test.js'));
+  }
+
+  Path get testJsDepsFilePath {
+    return suite.TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('test.js.deps'));
+  }
+
+  Path get testSnapshotFilePath {
+    return suite.TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('test_dart2js.snapshot'));
+  }
+
+  void touchFile(File file) {
+    _writeToFile(file, _readFile(file));
+  }
+
+  void _writeToFile(File file, String content) {
+    if (content != null) {
+      var fd = new File(file.fullPathSync()).openSync(FileMode.WRITE);
+      fd.writeStringSync(content);
+      fd.closeSync();
+    }
+  }
+
+  String _readFile(File file) {
+    return file.readAsStringSync();
+  }
+
+  File _createFile(Path path) {
+    var file = new File(path.toNativePath());
+    file.createSync();
+    return file;
+  }
+}
+
+class TestCompletedHandler {
+  FileUtils fileUtils;
+  Date _expectedTimestamp;
+  bool _shouldHaveRun;
+
+  TestCompletedHandler(FileUtils this.fileUtils, bool this._shouldHaveRun);
+
+  void processCompletedTest(runner.TestCase testCase) {
+    var output = testCase.lastCommandOutput;
+
+    Expect.isFalse(output.unexpectedOutput);
+    Expect.isTrue(output.stderr.length == 0);
+    if (_shouldHaveRun) {
+      Expect.isTrue(output.stdout.length == 0);
+      Expect.isTrue(new File(fileUtils.scriptOutputPath.toNativePath())
+          .existsSync());
+    } else {
+      Expect.isFalse(new File(fileUtils.scriptOutputPath.toNativePath())
+          .existsSync());
+    }
+    fileUtils.cleanup();
+  }
+}
+
+runner.TestCase makeTestCase(String testName,
+                             TestCompletedHandler completedHandler) {
+  var fileUtils = completedHandler.fileUtils;
+  var config = new options.TestOptionsParser().parse(['--timeout', '2'])[0];
+  var scriptDirPath = new Path.fromNative(new Options().script).directoryPath;
+  var createFileScript = scriptDirPath.
+      append('skipping_dart2js_compilations_helper.dart').toNativePath();
+  var executable = new Options().executable;
+  var arguments = [createFileScript, fileUtils.scriptOutputPath.toNativePath()];
+  var bootstrapDeps = [
+      new Uri("file://${fileUtils.testSnapshotFilePath}")];
+  var commands = [new runner.Dart2JsCommand(
+      fileUtils.testJsFilePath.toNativePath(),
+      false,
+      bootstrapDeps,
+      executable,
+      arguments)];
+  return new runner.TestCase(
+      testName,
+      commands,
+      config,
+      completedHandler.processCompletedTest,
+      new Set<String>.from([status.PASS]));
+}
+
+void main() {
+  var fs_noTestJs = new FileUtils(createJs: false,
+                                  createJsDeps: true,
+                                  createDart: true,
+                                  createSnapshot: true);
+  var fs_noTestJsDeps = new FileUtils(createJs: true,
+                                      createJsDeps: false,
+                                      createDart: true,
+                                      createSnapshot: true);
+  var fs_noTestDart = new FileUtils(createJs: true,
+                                    createJsDeps: true,
+                                    createDart: false,
+                                    createSnapshot: true);
+  var fs_noTestSnapshot = new FileUtils(createJs: true,
+                                        createJsDeps: true,
+                                        createDart: true,
+                                        createSnapshot: false);
+  var fs_notUpToDate_snapshot = new FileUtils(createJs: true,
+                                              createJsDeps: true,
+                                              createDart: true,
+                                              createSnapshot: true);
+  var fs_notUpToDate_dart = new FileUtils(createJs: true,
+                                          createJsDeps: true,
+                                          createDart: true,
+                                          createSnapshot: true);
+  var fs_upToDate = new FileUtils(createJs: true,
+                                  createJsDeps: true,
+                                  createDart: true,
+                                  createSnapshot: true);
+
+  void touchFilesAndRunTests(Timer unused) {
+    fs_notUpToDate_snapshot.touchFile(fs_notUpToDate_snapshot.testSnapshot);
+    fs_notUpToDate_dart.touchFile(fs_notUpToDate_dart.testDart);
+    fs_upToDate.touchFile(fs_upToDate.testJs);
+
+    void runTest(String name, FileUtils fileUtils, bool shouldRun) {
+      new runner.RunningProcess(makeTestCase(name,
+          new TestCompletedHandler(fileUtils, shouldRun))).start();
+    }
+    runTest("fs_noTestJs", fs_noTestJs, true);
+    runTest("fs_noTestJsDeps", fs_noTestJsDeps, true);
+    runTest("fs_noTestDart", fs_noTestDart, true);
+    runTest("fs_noTestSnapshot", fs_noTestSnapshot, true);
+    runTest("fs_notUpToDate_snapshot", fs_notUpToDate_snapshot, true);
+    runTest("fs_notUpToDate_dart", fs_notUpToDate_dart, true);
+    // This is the only test where all dependencies are present and the test.js
+    // file is newer than all the others. So we pass 'false' for shouldRun.
+    runTest("fs_upToDate", fs_upToDate, false);
+  }
+  // We need to wait some time to make sure that the files we 'touch' get a
+  // bigger timestamp than the old ones
+  new Timer(1000, touchFilesAndRunTests);
+}