Suggest that people move to "beta" when they upgrade on "master" (#127146)

Similar to https://github.com/flutter/flutter/pull/126972 but for master
upgrades.
Co-authored-by: Tim Sneath <timsneath@google.com>

packages/flutter_tools/lib/src/commands/upgrade.dart

@@ -47,6 +47,7 @@ class UpgradeCommand extends FlutterCommand {
         hide: !verboseHelp,
         help: 'Override the upgrade working directory. '
               'This is only intended to enable integration testing of the tool itself.'
+              // Also notably, this will override the FakeFlutterVersion if any is set!
       )
       ..addFlag(
         'verify-only',
@@ -88,7 +89,7 @@ class UpgradeCommand extends FlutterCommand {
 @visibleForTesting
 class UpgradeCommandRunner {
 
-  String? workingDirectory;
+  String? workingDirectory; // set in runCommand() above
 
   Future<FlutterCommandResult> runCommand({
     required bool force,
@@ -209,6 +210,22 @@ class UpgradeCommandRunner {
     await runDoctor();
     // Force the welcome message to re-display following the upgrade.
     persistentToolState.setShouldRedisplayWelcomeMessage(true);
+    if (globals.flutterVersion.channel == 'master' || globals.flutterVersion.channel == 'main') {
+      globals.printStatus(
+        '\n'
+        'This channel is intended for Flutter contributors. '
+        'This channel is not as thoroughly tested as the "beta" and "stable" channels. '
+        'We do not recommend using this channel for normal use as it more likely to contain serious regressions.\n'
+        '\n'
+        'For information on contributing to Flutter, see our contributing guide:\n'
+        '    https://github.com/flutter/flutter/blob/master/CONTRIBUTING.md\n'
+        '\n'
+        'For the most up to date stable version of flutter, consider using the "beta" channel instead. '
+        'The Flutter "beta" channel enjoys all the same automated testing as the "stable" channel, '
+        'but is updated roughly once a month instead of once a quarter.\n'
+        'To change channel, run the "flutter channel beta" command.',
+      );
+    }
   }
 
   Future<bool> hasUncommittedChanges() async {

packages/flutter_tools/test/commands.shard/hermetic/upgrade_test.dart

@@ -23,7 +23,6 @@ void main() {
   late FakeProcessManager processManager;
   UpgradeCommand command;
   late CommandRunner<void> runner;
-  late FlutterVersion flutterVersion;
 
   setUpAll(() {
     Cache.disableLocking();
@@ -41,7 +40,6 @@ void main() {
 
   testUsingContext('can auto-migrate a user from dev to beta', () async {
     const String startingTag = '3.0.0-1.2.pre';
-    flutterVersion = FakeFlutterVersion(channel: 'dev');
     const String latestUpstreamTag = '3.0.0-1.3.pre';
     const String upstreamHeadRevision = 'deadbeef';
     final Completer<void> reEntryCompleter = Completer<void>();
@@ -116,7 +114,157 @@ void main() {
     expect(logger.statusText, contains("Transitioning from 'dev' to 'beta'..."));
   }, overrides: <Type, Generator>{
     FileSystem: () => fileSystem,
-    FlutterVersion: () => flutterVersion,
+    FlutterVersion: () => FakeFlutterVersion(channel: 'dev'),
+    Logger: () => logger,
+    ProcessManager: () => processManager,
+  });
+
+  const String startingTag = '3.0.0';
+  const String latestUpstreamTag = '3.1.0';
+  const String upstreamHeadRevision = '5765737420536964652053746f7279';
+
+  testUsingContext('can push people from master to beta', () async {
+    final Completer<void> reEntryCompleter = Completer<void>();
+
+    Future<void> reEnterTool() async {
+      await runner.run(<String>['upgrade', '--continue', '--no-version-check']);
+      reEntryCompleter.complete();
+    }
+
+    processManager.addCommands(<FakeCommand>[
+      const FakeCommand(
+        command: <String>['git', 'tag', '--points-at', 'HEAD'],
+        stdout: startingTag,
+      ),
+      const FakeCommand(
+        command: <String>['git', 'fetch', '--tags'],
+      ),
+      const FakeCommand(
+        command: <String>['git', 'rev-parse', '--verify', '@{upstream}'],
+        stdout: upstreamHeadRevision,
+      ),
+      const FakeCommand(
+        command: <String>['git', 'tag', '--points-at', upstreamHeadRevision],
+        stdout: latestUpstreamTag,
+      ),
+      const FakeCommand(
+        command: <String>['git', 'status', '-s'],
+      ),
+      const FakeCommand(
+        command: <String>['git', 'reset', '--hard', upstreamHeadRevision],
+      ),
+      FakeCommand(
+        command: const <String>['bin/flutter', 'upgrade', '--continue', '--no-version-check'],
+        onRun: reEnterTool,
+        completer: reEntryCompleter,
+      ),
+
+      // commands following this are from the re-entrant `flutter upgrade --continue` call
+
+      const FakeCommand(
+        command: <String>['git', 'tag', '--points-at', 'HEAD'],
+        stdout: latestUpstreamTag,
+      ),
+      const FakeCommand(
+        command: <String>['bin/flutter', '--no-color', '--no-version-check', 'precache'],
+      ),
+      const FakeCommand(
+        command: <String>['bin/flutter', '--no-version-check', 'doctor'],
+      ),
+    ]);
+    await runner.run(<String>['upgrade']);
+    expect(processManager, hasNoRemainingExpectations);
+    expect(logger.statusText,
+      'Upgrading Flutter to 3.1.0 from 3.0.0 in ${Cache.flutterRoot}...\n'
+      '\n'
+      'Upgrading engine...\n'
+      '\n'
+      "Instance of 'FakeFlutterVersion'\n" // the real FlutterVersion has a better toString, heh
+      '\n'
+      'Running flutter doctor...\n'
+      '\n'
+      'This channel is intended for Flutter contributors. This channel is not as thoroughly '
+      'tested as the "beta" and "stable" channels. We do not recommend using this channel '
+      'for normal use as it more likely to contain serious regressions.\n'
+      '\n'
+      'For information on contributing to Flutter, see our contributing guide:\n'
+      '    https://github.com/flutter/flutter/blob/master/CONTRIBUTING.md\n'
+      '\n'
+      'For the most up to date stable version of flutter, consider using the "beta" channel '
+      'instead. The Flutter "beta" channel enjoys all the same automated testing as the '
+      '"stable" channel, but is updated roughly once a month instead of once a quarter.\n'
+      'To change channel, run the "flutter channel beta" command.\n'
+    );
+  }, overrides: <Type, Generator>{
+    FileSystem: () => fileSystem,
+    FlutterVersion: () => FakeFlutterVersion(channel: 'master', frameworkVersion: startingTag, engineRevision: 'engine'),
+    Logger: () => logger,
+    ProcessManager: () => processManager,
+  });
+
+  testUsingContext('do not push people from beta to anything else', () async {
+    final Completer<void> reEntryCompleter = Completer<void>();
+
+    Future<void> reEnterTool() async {
+      await runner.run(<String>['upgrade', '--continue', '--no-version-check']);
+      reEntryCompleter.complete();
+    }
+
+    processManager.addCommands(<FakeCommand>[
+      const FakeCommand(
+        command: <String>['git', 'tag', '--points-at', 'HEAD'],
+        stdout: startingTag,
+      ),
+      const FakeCommand(
+        command: <String>['git', 'fetch', '--tags'],
+      ),
+      const FakeCommand(
+        command: <String>['git', 'rev-parse', '--verify', '@{upstream}'],
+        stdout: upstreamHeadRevision,
+      ),
+      const FakeCommand(
+        command: <String>['git', 'tag', '--points-at', upstreamHeadRevision],
+        stdout: latestUpstreamTag,
+      ),
+      const FakeCommand(
+        command: <String>['git', 'status', '-s'],
+      ),
+      const FakeCommand(
+        command: <String>['git', 'reset', '--hard', upstreamHeadRevision],
+      ),
+      FakeCommand(
+        command: const <String>['bin/flutter', 'upgrade', '--continue', '--no-version-check'],
+        onRun: reEnterTool,
+        completer: reEntryCompleter,
+      ),
+
+      // commands following this are from the re-entrant `flutter upgrade --continue` call
+
+      const FakeCommand(
+        command: <String>['git', 'tag', '--points-at', 'HEAD'],
+        stdout: latestUpstreamTag,
+      ),
+      const FakeCommand(
+        command: <String>['bin/flutter', '--no-color', '--no-version-check', 'precache'],
+      ),
+      const FakeCommand(
+        command: <String>['bin/flutter', '--no-version-check', 'doctor'],
+      ),
+    ]);
+    await runner.run(<String>['upgrade']);
+    expect(processManager, hasNoRemainingExpectations);
+    expect(logger.statusText,
+      'Upgrading Flutter to 3.1.0 from 3.0.0 in ${Cache.flutterRoot}...\n'
+      '\n'
+      'Upgrading engine...\n'
+      '\n'
+      "Instance of 'FakeFlutterVersion'\n" // the real FlutterVersion has a better toString, heh
+      '\n'
+      'Running flutter doctor...\n'
+    );
+  }, overrides: <Type, Generator>{
+    FileSystem: () => fileSystem,
+    FlutterVersion: () => FakeFlutterVersion(channel: 'beta', frameworkVersion: startingTag, engineRevision: 'engine'),
     Logger: () => logger,
     ProcessManager: () => processManager,
   });