Added support for skipping redundant dart2js compilations.

tests/standalone/io/skipping_dart2js_compilations_test.dart

+// 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.
+

[ahe, 2012/12/11 14:34:45]

Please add a comment explaining the purpose of this test.

[kustermann, 2012/12/14 11:55:47]

Done.

+#import("dart:io");

[ahe, 2012/12/11 14:34:45]

#import -> import.

[kustermann, 2012/12/14 11:55:47]

Done.

+#import("dart:isolate");
+#import("dart:uri");
+#import("../../../tools/testing/dart/test_suite.dart");

[ahe, 2012/12/11 14:34:45]

It would be nice if these were imported with prefixes.

[kustermann, 2012/12/14 11:55:47]

Done.

+#import("../../../tools/testing/dart/test_runner.dart");
+#import("../../../tools/testing/dart/test_options.dart");
+#import("../../../tools/testing/dart/status_file_parser.dart");
+
+class FsUtils {

[ahe, 2012/12/11 14:34:45]

What does this class do?

[kustermann, 2012/12/14 11:55:47]

I renamed it now to FileUtils.

+  Directory tempDir;
+  File testJs;
+  File testJsDeps;
+  File testDart;
+  File testSnapshot;
+
+  FsUtils({bool createJs,
+           bool createJsDeps,
+           bool createDart,
+           bool createSnapshot}) {
+    tempDir = new Directory('').createTempSync();

[ahe, 2012/12/11 14:34:45]

I'm allergic to doing work in constructors.  I think it is poor coding style.  I
go straight into anaphylactic shock when you start creating files in a
constructor.

[kustermann, 2012/12/14 11:55:47]

IMHO neither readability, nor code size would be improved by  making it an extra
method. And this way, we're sure that after the object had been created, all the
necessary files have been created as well.
 
But I agree with you in general: normally we don't want constructors to do a lot
of work.

+    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 = 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 TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('created_if_command_did_run.txt'));
+  }
+
+  Path get testDartFilePath {
+    return TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('test.dart'));
+  }
+
+  Path get testJsFilePath {
+    return TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('test.js'));
+  }
+
+  Path get testJsDepsFilePath {
+    return TestUtils.absolutePath(new Path.fromNative(tempDir.path)
+        .append('test.js.deps'));
+  }
+
+  Path get testSnapshotFilePath {
+    return 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 {
+  FsUtils fsUtils;
+  Date _expectedTimestamp;
+  bool _shouldHaveRun;
+
+  TestCompletedHandler(FsUtils this.fsUtils, bool this._shouldHaveRun);
+
+  void processCompletedTest(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(fsUtils.scriptOutputPath.toNativePath())
+          .existsSync());
+    } else {
+      Expect.isFalse(new File(fsUtils.scriptOutputPath.toNativePath())
+          .existsSync());
+    }
+    fsUtils.cleanup();
+  }
+}
+
+TestCase MakeTestCase(String testName, TestCompletedHandler completedHandler) {

[ahe, 2012/12/11 14:34:45]

MakeTestCase -> makeTestCase.

[kustermann, 2012/12/14 11:55:47]

Done.

+  var fsUtils = completedHandler.fsUtils;
+  var config = new 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, fsUtils.scriptOutputPath.toNativePath()];
+  var bootstrapDeps = [
+      new Uri("file://${fsUtils.testSnapshotFilePath}")];
+  var commands = [new Dart2JsCommand(fsUtils.testJsFilePath.toNativePath(),
+      false, bootstrapDeps, executable, arguments)];
+  return new TestCase(testName, commands, config,
+      completedHandler.processCompletedTest, new Set<String>.from([PASS]));
+}
+
+void main() {
+  var fs_noTestJs = new FsUtils(createJs: false,
+                                createJsDeps: true,
+                                createDart: true,
+                                createSnapshot: true);
+  var fs_noTestJsDeps = new FsUtils(createJs: true,
+                                    createJsDeps: false,
+                                    createDart: true,
+                                    createSnapshot: true);
+  var fs_noTestDart = new FsUtils(createJs: true,
+                                  createJsDeps: true,
+                                  createDart: false,
+                                  createSnapshot: true);
+  var fs_noTestSnapshot = new FsUtils(createJs: true,
+                                      createJsDeps: true,
+                                      createDart: true,
+                                      createSnapshot: false);
+  var fs_notUpToDate_snapshot = new FsUtils(createJs: true,
+                                            createJsDeps: true,
+                                            createDart: true,
+                                            createSnapshot: true);
+  var fs_notUpToDate_dart = new FsUtils(createJs: true,
+                                        createJsDeps: true,
+                                        createDart: true,
+                                        createSnapshot: true);
+  var fs_upToDate = new FsUtils(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, FsUtils fsUtils, bool shouldRun) {
+      new RunningProcess(MakeTestCase(name,
+          new TestCompletedHandler(fsUtils, 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);
+}