Add tests for publish check tool command (#3760)

script/tool/lib/src/publish_check_command.dart

@@ -65,10 +65,10 @@ class PublishCheckCommand extends PluginCommand {
   }
 
   Future<bool> hasValidPublishCheckRun(Directory package) async {
-    final io.Process process = await io.Process.start(
+    final io.Process process = await processRunner.start(
       'flutter',
       <String>['pub', 'publish', '--', '--dry-run'],
-      workingDirectory: package.path,
+      workingDirectory: package,
     );
 
     final StringBuffer outputBuffer = StringBuffer();

script/tool/test/publish_check_command_test.dart

@@ -0,0 +1,114 @@
+// Copyright 2013 The Flutter Authors. 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:collection';
+import 'dart:io' as io;
+
+import 'package:args/command_runner.dart';
+import 'package:file/file.dart';
+import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/publish_check_command.dart';
+import 'package:test/test.dart';
+
+import 'mocks.dart';
+import 'util.dart';
+
+void main() {
+  group('$PublishCheckProcessRunner tests', () {
+    PublishCheckProcessRunner processRunner;
+    CommandRunner runner;
+
+    setUp(() {
+      initializeFakePackages();
+      processRunner = PublishCheckProcessRunner();
+      final PublishCheckCommand publishCheckCommand = PublishCheckCommand(
+          mockPackagesDir, mockFileSystem,
+          processRunner: processRunner);
+
+      runner = CommandRunner<Null>(
+        'publish_check_command',
+        'Test for publish-check command.',
+      );
+      runner.addCommand(publishCheckCommand);
+    });
+
+    tearDown(() {
+      mockPackagesDir.deleteSync(recursive: true);
+    });
+
+    test('publish check all packages', () async {
+      final Directory plugin1Dir = await createFakePlugin('a');
+      final Directory plugin2Dir = await createFakePlugin('b');
+
+      processRunner.processesToReturn.add(
+        MockProcess()..exitCodeCompleter.complete(0),
+      );
+      processRunner.processesToReturn.add(
+        MockProcess()..exitCodeCompleter.complete(0),
+      );
+      await runner.run(<String>['publish-check']);
+
+      expect(
+          processRunner.recordedCalls,
+          orderedEquals(<ProcessCall>[
+            ProcessCall('flutter',
+                <String>['pub', 'publish', '--', '--dry-run'], plugin1Dir.path),
+            ProcessCall('flutter',
+                <String>['pub', 'publish', '--', '--dry-run'], plugin2Dir.path),
+          ]));
+    });
+
+    test('fail on negative test', () async {
+      await createFakePlugin('a');
+
+      final MockProcess process = MockProcess();
+      process.stdoutController.close(); // ignore: unawaited_futures
+      process.stderrController.close(); // ignore: unawaited_futures
+      process.exitCodeCompleter.complete(1);
+
+      processRunner.processesToReturn.add(process);
+
+      expect(
+        () => runner.run(<String>['publish-check']),
+        throwsA(isA<ToolExit>()),
+      );
+    });
+
+    test('fail on bad pubspec', () async {
+      final Directory dir = await createFakePlugin('c');
+      await dir.childFile('pubspec.yaml').writeAsString('bad-yaml');
+
+      final MockProcess process = MockProcess();
+      processRunner.processesToReturn.add(process);
+
+      expect(() => runner.run(<String>['publish-check']),
+          throwsA(isA<ToolExit>()));
+    });
+
+    test('pass on prerelease', () async {
+      await createFakePlugin('d');
+
+      final String preReleaseOutput = 'Package has 1 warning.'
+          'Packages with an SDK constraint on a pre-release of the Dart SDK should themselves be published as a pre-release version.';
+
+      final MockProcess process = MockProcess();
+      process.stdoutController.add(preReleaseOutput.codeUnits);
+      process.stdoutController.close(); // ignore: unawaited_futures
+      process.stderrController.close(); // ignore: unawaited_futures
+
+      process.exitCodeCompleter.complete(1);
+
+      processRunner.processesToReturn.add(process);
+
+      expect(runner.run(<String>['publish-check']), completes);
+    });
+  });
+}
+
+class PublishCheckProcessRunner extends RecordingProcessRunner {
+  final Queue<MockProcess> processesToReturn = Queue<MockProcess>();
+
+  @override
+  io.Process get processToReturn => processesToReturn.removeFirst();
+}