When using revert-bot, it applies the right base-ref/branch-name. (#4689)

Closes flutter/flutter#168926.

Author: matanlurey

auto_submit/lib/action/git_cli_revert_method.dart

@@ -6,6 +6,7 @@ import 'dart:io';
 
 import 'package:cocoon_server/logging.dart';
 import 'package:github/github.dart' as github;
+import 'package:meta/meta.dart';
 import 'package:retry/retry.dart';
 
 import '../git/cli_command.dart';
@@ -19,6 +20,11 @@ import '../service/github_service.dart';
 import 'revert_method.dart';
 
 class GitCliRevertMethod implements RevertMethod {
+  GitCliRevertMethod({
+    @visibleForTesting GitCli? gitCli, //
+  }) : _gitCli = gitCli ?? GitCli(GitAccessMethod.HTTP, CliCommand());
+  final GitCli _gitCli;
+
   @override
   Future<github.PullRequest?> createRevert(
     Config config,
@@ -30,17 +36,14 @@ class GitCliRevertMethod implements RevertMethod {
     final commitSha = pullRequestToRevert.mergeCommitSha!;
     // we will need to collect the pr number after the revert request is generated.
 
-    final repositoryConfiguration = await config.getRepositoryConfiguration(
-      slug,
-    );
-    final baseBranch = repositoryConfiguration.defaultBranch;
+    final baseBranch = pullRequestToRevert.base!.ref!;
 
     final cloneToDirectory = '${slug.name}_$commitSha';
     final gitRepositoryManager = GitRepositoryManager(
       slug: slug,
       workingDirectory: Directory.current.path,
       cloneToDirectory: cloneToDirectory,
-      gitCli: GitCli(GitAccessMethod.HTTP, CliCommand()),
+      gitCli: _gitCli,
     );
 
     // The exception is caught by the thrower.

auto_submit/test/action/git_cli_revert_method_test.dart

@@ -0,0 +1,163 @@
+// Copyright 2023 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:io';
+
+import 'package:auto_submit/action/git_cli_revert_method.dart';
+import 'package:auto_submit/git/git_cli.dart';
+import 'package:auto_submit/service/config.dart';
+import 'package:auto_submit/service/github_service.dart';
+import 'package:cocoon_server_test/test_logging.dart';
+import 'package:github/src/common/model/pulls.dart';
+import 'package:github/src/common/model/repos.dart';
+import 'package:test/fake.dart';
+import 'package:test/test.dart';
+
+import '../requests/github_webhook_test_data.dart';
+
+void main() {
+  useTestLoggerPerTest();
+
+  late _FakeGitCli gitCli;
+
+  setUp(() {
+    gitCli = _FakeGitCli();
+  });
+
+  test('createRevert uses the branch from the originating PR', () async {
+    final config = _FakeConfig();
+    final method = GitCliRevertMethod(gitCli: gitCli);
+    final revert = await method.createRevert(
+      config,
+      'matanlurey',
+      'I said so',
+      generatePullRequest(
+        baseRef: 'flutter-3.32-candidate.0',
+        mergeCommitSha: 'abc123',
+      ),
+    );
+    expect(gitCli.createBranch$newBranchName, 'revert_abc123');
+    expect(gitCli.setUpstream$branchName, 'revert_abc123');
+    expect(gitCli.pushBranch$branchName, 'revert_abc123');
+    expect(revert?.base?.ref, 'flutter-3.32-candidate.0');
+  });
+}
+
+final class _FakeConfig extends Fake implements Config {
+  @override
+  Future<String> generateGithubToken(RepositorySlug slug) async {
+    return 'a_github_token';
+  }
+
+  @override
+  Future<GithubService> createGithubService(RepositorySlug slug) async {
+    return _FakeGithubService();
+  }
+}
+
+final class _FakeGithubService extends Fake implements GithubService {
+  @override
+  Future<Branch> getBranch(RepositorySlug slug, String branchName) async {
+    return Branch(branchName, null);
+  }
+
+  @override
+  Future<List<PullRequestReview>> getPullRequestReviews(
+    RepositorySlug slug,
+    int pullRequestNumber,
+  ) async {
+    return [];
+  }
+
+  @override
+  Future<PullRequest> createPullRequest({
+    required RepositorySlug slug,
+    String? title,
+    String? head,
+    required String base,
+    bool draft = false,
+    String? body,
+  }) async {
+    return PullRequest(base: PullRequestHead(ref: base));
+  }
+}
+
+final class _FakeGitCli extends Fake implements GitCli {
+  @override
+  Future<ProcessResult> cloneRepository({
+    required RepositorySlug slug,
+    required String workingDirectory,
+    required String targetDirectory,
+    List<String>? options,
+    bool throwOnError = true,
+  }) async {
+    return ProcessResult(0, 0, '', '');
+  }
+
+  @override
+  Future<ProcessResult> setupUserConfig({
+    required RepositorySlug slug,
+    required String workingDirectory,
+    bool throwOnError = true,
+  }) async {
+    return ProcessResult(0, 0, '', '');
+  }
+
+  @override
+  Future<ProcessResult> setupUserEmailConfig({
+    required RepositorySlug slug,
+    required String workingDirectory,
+    bool throwOnError = true,
+  }) async {
+    return ProcessResult(0, 0, '', '');
+  }
+
+  late String createBranch$newBranchName;
+
+  @override
+  Future<ProcessResult> createBranch({
+    required String newBranchName,
+    required String workingDirectory,
+    bool useCheckout = false,
+    bool throwOnError = true,
+  }) async {
+    createBranch$newBranchName = newBranchName;
+    return ProcessResult(0, 0, '', '');
+  }
+
+  late String setUpstream$branchName;
+
+  @override
+  Future<ProcessResult> setUpstream({
+    required RepositorySlug slug,
+    required String workingDirectory,
+    required String branchName,
+    required String token,
+    bool throwOnError = true,
+  }) async {
+    setUpstream$branchName = branchName;
+    return ProcessResult(0, 0, '', '');
+  }
+
+  @override
+  Future<ProcessResult> revertChange({
+    required String commitSha,
+    required String workingDirectory,
+    bool throwOnError = true,
+  }) async {
+    return ProcessResult(0, 0, '', '');
+  }
+
+  late String pushBranch$branchName;
+
+  @override
+  Future<ProcessResult> pushBranch({
+    required String branchName,
+    required String workingDirectory,
+    bool throwOnError = true,
+  }) async {
+    pushBranch$branchName = branchName;
+    return ProcessResult(0, 0, '', '');
+  }
+}

auto_submit/test/requests/github_webhook_test_data.dart

@@ -94,6 +94,7 @@ PullRequest generatePullRequest({
   bool? mergeable = true,
   String baseRef = 'main',
   DateTime? mergedAt,
+  String mergeCommitSha = 'abc123',
 }) {
   return PullRequest.fromJson(
     json.decode('''{
@@ -119,6 +120,7 @@ PullRequest generatePullRequest({
       ],
       "created_at": "2011-01-26T19:01:12Z",
       "merged_at": "${mergedAt ?? DateTime.now().subtract(const Duration(hours: 12))}",
+      "merge_commit_sha": "$mergeCommitSha",
       "closed_at": "2011-01-26T19:10:12Z",
       "head": {
         "label": "octocat:new-topic",