[flutter_conductor] Support publishing to multiple channels (#94770)

dev/conductor/core/lib/src/globals.dart

@@ -16,7 +16,7 @@ const List<String> kBaseReleaseChannels = <String>['stable', 'beta', 'dev'];
 
 const List<String> kReleaseChannels = <String>[...kBaseReleaseChannels, FrameworkRepository.defaultBranch];
 
-const List<String> KReleaseIncrements = <String>['y', 'z', 'm', 'n'];
+const List<String> kReleaseIncrements = <String>['y', 'z', 'm', 'n'];
 
 const String kReleaseDocumentationUrl = 'https://github.com/flutter/flutter/wiki/Flutter-Cherrypick-Process';
 
@@ -28,6 +28,10 @@ final RegExp releaseCandidateBranchRegex = RegExp(
   r'flutter-(\d+)\.(\d+)-candidate\.(\d+)',
 );
 
+/// Whether all releases published to the beta channel should be mirrored to
+/// dev.
+const bool kSynchronizeDevWithBeta = true;
+
 /// Cast a dynamic to String and trim.
 String stdoutToString(dynamic input) {
   final String str = input as String;

dev/conductor/core/lib/src/next.dart

@@ -48,7 +48,7 @@ class NextCommand extends Command<void> {
   String get description => 'Proceed to the next release phase.';
 
   @override
-  Future<void> run() async {
+  Future<void> run() {
     final File stateFile = checkouts.fileSystem.file(argResults![kStateOption]);
     if (!stateFile.existsSync()) {
       throw ConductorException(
@@ -57,7 +57,7 @@ class NextCommand extends Command<void> {
     }
     final pb.ConductorState state = state_import.readStateFromFile(stateFile);
 
-    await NextContext(
+    return NextContext(
       autoAccept: argResults![kYesFlag] as bool,
       checkouts: checkouts,
       force: argResults![kForceFlag] as bool,
@@ -324,17 +324,24 @@ class NextContext extends Context {
             previousCheckoutLocation: state.framework.checkoutPath,
         );
         final String headRevision = await framework.reverseParse('HEAD');
+        final List<String> releaseRefs = <String>[state.releaseChannel];
+        if (kSynchronizeDevWithBeta && state.releaseChannel == 'beta') {
+          releaseRefs.add('dev');
+        }
+        for (final String releaseRef in releaseRefs) {
           if (autoAccept == false) {
             // dryRun: true means print out git command
             await framework.pushRef(
               fromRef: headRevision,
-              toRef: state.releaseChannel,
+              toRef: releaseRef,
               remote: state.framework.upstream.url,
               force: force,
               dryRun: true,
             );
 
-          final bool response = await prompt('Are you ready to publish this release?');
+            final bool response = await prompt(
+              'Are you ready to publish version ${state.releaseVersion} to $releaseRef?',
+            );
             if (!response) {
               stdio.printError('Aborting command.');
               updateState(state, stdio.logs);
@@ -343,10 +350,11 @@ class NextContext extends Context {
           }
           await framework.pushRef(
             fromRef: headRevision,
-            toRef: state.releaseChannel,
+            toRef: releaseRef,
             remote: state.framework.upstream.url,
             force: force,
           );
+        }
         break;
       case pb.ReleasePhase.VERIFY_RELEASE:
         stdio.printStatus(

dev/conductor/core/lib/src/start.dart

@@ -93,7 +93,7 @@ class StartCommand extends Command<void> {
       kIncrementOption,
       help: 'Specifies which part of the x.y.z version number to increment. Required.',
       valueHelp: 'level',
-      allowed: KReleaseIncrements,
+      allowed: kReleaseIncrements,
       allowedHelp: <String, String>{
         'y': 'Indicates the first dev release after a beta release.',
         'z': 'Indicates a hotfix to a stable release.',

dev/conductor/core/lib/src/version.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import './globals.dart' show ConductorException, KReleaseIncrements, releaseCandidateBranchRegex;
+import './globals.dart' show ConductorException, kReleaseIncrements, releaseCandidateBranchRegex;
 
 /// Possible string formats that `flutter --version` can return.
 enum VersionType {
@@ -262,7 +262,7 @@ class Version {
   /// Will throw a [ConductorException] if the version is not possible given the
   /// [candidateBranch] and [incrementLetter].
   void ensureValid(String candidateBranch, String incrementLetter) {
-    if (!KReleaseIncrements.contains(incrementLetter)) {
+    if (!kReleaseIncrements.contains(incrementLetter)) {
       throw ConductorException('Invalid incrementLetter: $incrementLetter');
     }
     final RegExpMatch? branchMatch = releaseCandidateBranchRegex.firstMatch(candidateBranch);

dev/conductor/core/test/common.dart

@@ -48,7 +48,7 @@ class TestStdio extends Stdio {
   @override
   String readLineSync() {
     if (stdin.isEmpty) {
-      throw Exception('Unexpected call to readLineSync!');
+      throw Exception('Unexpected call to readLineSync! Last stdout was ${logs.last}');
     }
     return stdin.removeAt(0);
   }

dev/conductor/core/test/next_test.dart

@@ -966,6 +966,8 @@ void main() {
       });
 
       test('updates currentPhase if user responds yes', () async {
+        stdio.stdin.add('y');
+        // for kSynchronizeDevWithBeta
         stdio.stdin.add('y');
         final FakeProcessManager processManager = FakeProcessManager.list(<FakeCommand>[
           const FakeCommand(
@@ -981,6 +983,10 @@ void main() {
           const FakeCommand(
             command: <String>['git', 'push', FrameworkRepository.defaultUpstream, '$revision1:$releaseChannel'],
           ),
+          // for kSynchronizeDevWithBeta
+          const FakeCommand(
+            command: <String>['git', 'push', FrameworkRepository.defaultUpstream, '$revision1:dev'],
+          ),
         ]);
         writeStateToFile(
           fileSystem.file(stateFile),