Add an initial tests for dartdev that can execute and pass on the Dart build bots, as well as locally.

Change-Id: I92b24b7b5252d2f2dab97fe552406b7e97fc927c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/132703
Reviewed-by: Devon Carew <devoncarew@google.com>
Commit-Queue: Jaime Wren <jwren@google.com>

pkg/dartdev/test/command_test.dart

@@ -2,65 +2,27 @@
 // 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.
 
-import 'dart:io';
-
-import 'package:path/path.dart' as path;
+import 'package:dartdev/dartdev.dart';
 import 'package:test/test.dart';
 
-// TODO(jwren) move the following test utilities to a separate file
+import 'utils.dart';
 
-// Files that end in _test.dart must have a main method to satisfy the dart2js
-// bots
 void main() {
-  test('empty test for dart2js', () {
-    assert(true == true);
+  group('flag', flags);
+}
+
+void flags() {
+  TestProject p;
+  tearDown(() => p?.dispose());
+  test('--help', () {
+    p = project();
+
+    var result = p.runSync('--help');
+
+    expect(result.exitCode, 0);
+    expect(result.stdout, contains(DartdevRunner.dartdevDescription));
+    expect(result.stdout, contains('Usage: dartdev <command> [arguments]'));
+    expect(result.stdout, contains('Global options:'));
+    expect(result.stdout, contains('Available commands:'));
   });
 }
-
-TestProject project({String mainSrc}) => TestProject(mainSrc: mainSrc);
-
-class TestProject {
-  Directory dir;
-
-  static String get defaultProjectName => 'dartdev_temp';
-
-  String get name => defaultProjectName;
-
-  TestProject({String mainSrc}) {
-    dir = Directory.systemTemp.createTempSync('dartdev');
-    if (mainSrc != null) {
-      file('lib/main.dart', mainSrc);
-    }
-    file('pubspec.yaml', 'name: $name\ndev_dependencies:\n  test: any\n');
-  }
-
-  void file(String name, String contents) {
-    var file = File(path.join(dir.path, name));
-    file.parent.createSync();
-    file.writeAsStringSync(contents);
-  }
-
-  void dispose() {
-    dir.deleteSync(recursive: true);
-  }
-
-  ProcessResult run(String command, [List<String> args]) {
-    var arguments = [
-      path.absolute(path.join(Directory.current.path, 'bin', 'dartdev.dart')),
-      command
-    ];
-    if (args != null && args.isNotEmpty) {
-      arguments.addAll(args);
-    }
-    return Process.runSync(
-      Platform.resolvedExecutable,
-      arguments,
-      workingDirectory: dir.path,
-    );
-  }
-
-  File findFile(String name) {
-    var file = File(path.join(dir.path, name));
-    return file.existsSync() ? file : null;
-  }
-}

pkg/dartdev/test/utils.dart

@@ -0,0 +1,71 @@
+// Copyright (c) 2020, 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.
+
+import 'dart:io';
+
+import 'package:path/path.dart' as path;
+
+TestProject project({String mainSrc}) => TestProject(mainSrc: mainSrc);
+
+class TestProject {
+  Directory dir;
+
+  static String get defaultProjectName => 'dartdev_temp';
+
+  String get name => defaultProjectName;
+
+  TestProject({String mainSrc}) {
+    dir = Directory.systemTemp.createTempSync('dartdev');
+    if (mainSrc != null) {
+      file('lib/main.dart', mainSrc);
+    }
+    file('pubspec.yaml', 'name: $name\ndev_dependencies:\n  test: any\n');
+  }
+
+  void file(String name, String contents) {
+    var file = File(path.join(dir.path, name));
+    file.parent.createSync();
+    file.writeAsStringSync(contents);
+  }
+
+  void dispose() {
+    dir.deleteSync(recursive: true);
+  }
+
+  ProcessResult runSync(String command, [List<String> args]) {
+    var arguments = [
+      absolutePathToDartdevFile,
+      command,
+    ];
+
+    if (args != null && args.isNotEmpty) {
+      arguments.addAll(args);
+    }
+
+    return Process.runSync(
+      Platform.resolvedExecutable,
+      arguments,
+      workingDirectory: dir.path,
+    );
+  }
+
+  /// The path relative from `Directory.current.path` to `dartdev.dart` is
+  /// different when executing these tests locally versus on the Dart
+  /// buildbots, this if-else captures this change and branches for each case.
+  String get absolutePathToDartdevFile {
+    var dartdevFilePathOnBots = path.absolute(path.join(
+        Directory.current.path, 'pkg', 'dartdev', 'bin', 'dartdev.dart'));
+    if (File(dartdevFilePathOnBots).existsSync()) {
+      return dartdevFilePathOnBots;
+    } else {
+      return path
+          .absolute(path.join(Directory.current.path, 'bin', 'dartdev.dart'));
+    }
+  }
+
+  File findFile(String name) {
+    var file = File(path.join(dir.path, name));
+    return file.existsSync() ? file : null;
+  }
+}