Add Webdev installation test (#1935)

Author: elliette

webdev/test/installation_test.dart

@@ -0,0 +1,201 @@
+// Copyright (c) 2023, 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.
+
+@Timeout(Duration(seconds: 90))
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:path/path.dart' as p;
+import 'package:test/test.dart';
+
+// TODO(elliette): Move to a cron job. This tests that the currently published
+// Webdev can be activated and serve a web app. It is intended to catch any
+// regressions due to changes in the Dart SDK.
+
+enum StreamType {
+  stdout,
+  stderr,
+}
+
+const processTimeout = Duration(seconds: 30);
+
+void main() {
+  Process? _createProcess;
+  Process? _activateProcess;
+  Process? _serveProcess;
+  Directory? _tempDir;
+
+  Future<void> _expectStdoutAndCleanExit(Process process,
+      {required String expectedStdout}) async {
+    final stdoutCompleter = _captureOutput(
+      process,
+      streamType: StreamType.stdout,
+      stopCaptureFuture: process.exitCode,
+    );
+    final stderrCompleter = _captureOutput(
+      process,
+      streamType: StreamType.stderr,
+      stopCaptureFuture: process.exitCode,
+    );
+    final exitCode = await _waitForExitOrTimeout(process);
+    final stderrLogs = await stderrCompleter.future;
+    final stdoutLogs = await stdoutCompleter.future;
+    expect(
+      exitCode,
+      equals(0),
+      // Include the stderr and stdout logs if the process does not terminate
+      // cleanly:
+      reason: 'stderr: $stderrLogs, stdout: $stdoutLogs',
+    );
+    expect(
+      stderrLogs,
+      isEmpty,
+    );
+    expect(
+      stdoutLogs,
+      contains(expectedStdout),
+    );
+  }
+
+  Future<void> _expectStdoutThenExit(Process process,
+      {required String expectedStdout}) async {
+    final expectedStdoutCompleter = _waitForStdoutOrTimeout(
+      process,
+      expectedStdout: expectedStdout,
+    );
+    final stderrCompleter = _captureOutput(
+      process,
+      streamType: StreamType.stderr,
+      stopCaptureFuture: expectedStdoutCompleter.future,
+    );
+    final stdoutLogs = await expectedStdoutCompleter.future;
+    final stderrLogs = await stderrCompleter.future;
+    expect(
+      stdoutLogs, contains(expectedStdout),
+      // Also include the stderr if the stdout is not expected.
+      reason: 'stderr: $stderrLogs',
+    );
+  }
+
+  setUp(() async {
+    _tempDir = Directory.systemTemp.createTempSync('installation_test');
+
+    await Process.run(
+      'dart',
+      ['pub', 'global', 'deactivate', 'webdev'],
+    );
+  });
+
+  tearDown(() async {
+    // Kill any stale processes:
+    if (_createProcess != null) {
+      Process.killPid(_createProcess!.pid, ProcessSignal.sigint);
+      _createProcess = null;
+    }
+    if (_activateProcess != null) {
+      Process.killPid(_activateProcess!.pid, ProcessSignal.sigint);
+      _activateProcess = null;
+    }
+    if (_serveProcess != null) {
+      Process.killPid(_serveProcess!.pid, ProcessSignal.sigint);
+      _serveProcess = null;
+    }
+  });
+
+  test('can activate and serve webdev', () async {
+    final tempDir = _tempDir!;
+    final tempPath = tempDir.path;
+
+    // Verify that we can create a new Dart app:
+    _createProcess = await Process.start(
+      'dart',
+      ['create', '--template', 'web', 'temp_app'],
+      workingDirectory: tempPath,
+    );
+    await _expectStdoutAndCleanExit(
+      _createProcess!,
+      expectedStdout: 'Created project temp_app in temp_app!',
+    );
+    final appPath = p.join(tempPath, 'temp_app');
+    expect(await Directory(appPath).exists(), isTrue);
+
+    // Verify that `dart pub global activate` works:
+    _activateProcess = await Process.start(
+      'dart',
+      ['pub', 'global', 'activate', 'webdev'],
+    );
+    await _expectStdoutAndCleanExit(
+      _activateProcess!,
+      expectedStdout: 'Activated webdev',
+    );
+
+    // Verify that `webdev serve` works for our new app:
+    _serveProcess = await Process.start(
+        'dart', ['pub', 'global', 'run', 'webdev', 'serve'],
+        workingDirectory: appPath);
+    await _expectStdoutThenExit(_serveProcess!,
+        expectedStdout: 'Serving `web` on');
+  });
+}
+
+Future<int> _waitForExitOrTimeout(Process process) {
+  Timer(processTimeout, () {
+    process.kill(ProcessSignal.sigint);
+  });
+  return process.exitCode;
+}
+
+/// Returns the stdout for the [process] once the [expectedStdout] is found.
+///
+/// Otherwise returns all the stdout up to the [processTimeout].
+Completer<String> _waitForStdoutOrTimeout(Process process,
+    {required String expectedStdout}) {
+  var output = '';
+  final completer = Completer<String>();
+
+  Timer(processTimeout, () {
+    process.kill(ProcessSignal.sigint);
+    if (!completer.isCompleted) {
+      completer.complete(output);
+    }
+  });
+  process.stdout.transform(utf8.decoder).listen((line) {
+    output += line;
+    if (line.contains(expectedStdout)) {
+      process.kill(ProcessSignal.sigint);
+      if (!completer.isCompleted) {
+        completer.complete(output);
+      }
+    }
+  });
+
+  return completer;
+}
+
+Completer<String> _captureOutput(
+  Process process, {
+  required StreamType streamType,
+  required Future stopCaptureFuture,
+}) {
+  final stream =
+      streamType == StreamType.stdout ? process.stdout : process.stderr;
+  final completer = Completer<String>();
+  var output = '';
+  stream.transform(utf8.decoder).listen((line) {
+    output += line;
+    if (line.contains('[SEVERE]')) {
+      process.kill(ProcessSignal.sigint);
+      if (!completer.isCompleted) {
+        completer.complete(output);
+      }
+    }
+  });
+  unawaited(stopCaptureFuture.then((_) {
+    if (!completer.isCompleted) {
+      completer.complete(output);
+    }
+  }));
+  return completer;
+}