[flutter_tools] Remove --no-sound-null-safety #4 (flutter#124039)

Re-land of flutter#123297 without any of
the commits at the end attempting to fix customer-testing.

Fixes flutter#118810

Author: christopherfujino

dev/bots/test.dart

@@ -573,9 +573,7 @@ Future<void> _runExampleProjectBuildTests(Directory exampleDirectory, [File? mai
   // Only verify caching with flutter gallery.
   final bool verifyCaching = exampleDirectory.path.contains('flutter_gallery');
   final String examplePath = path.relative(exampleDirectory.path, from: Directory.current.path);
-  final bool hasNullSafety = File(path.join(examplePath, 'null_safety')).existsSync();
   final List<String> additionalArgs = <String>[
-    if (hasNullSafety) '--no-sound-null-safety',
     if (mainFile != null) path.relative(mainFile.path, from: exampleDirectory.absolute.path),
   ];
   if (Directory(path.join(examplePath, 'android')).existsSync()) {
@@ -771,16 +769,14 @@ Future<void> _runAddToAppLifeCycleTests() async {
 }
 
 Future<void> _runFrameworkTests() async {
-  final List<String> soundNullSafetyOptions     = <String>['--null-assertions', '--sound-null-safety'];
-  final List<String> mixedModeNullSafetyOptions = <String>['--null-assertions', '--no-sound-null-safety'];
   final List<String> trackWidgetCreationAlternatives = <String>['--track-widget-creation', '--no-track-widget-creation'];
 
   Future<void> runWidgets() async {
     printProgress('${green}Running packages/flutter tests $reset for ${cyan}test/widgets/$reset');
     for (final String trackWidgetCreationOption in trackWidgetCreationAlternatives) {
       await _runFlutterTest(
         path.join(flutterRoot, 'packages', 'flutter'),
-        options: <String>[trackWidgetCreationOption, ...soundNullSafetyOptions],
+        options: <String>[trackWidgetCreationOption],
         tests: <String>[ path.join('test', 'widgets') + path.separator ],
       );
     }
@@ -795,13 +791,13 @@ Future<void> _runFrameworkTests() async {
     // Run release mode tests (see packages/flutter/test_release/README.md)
     await _runFlutterTest(
       path.join(flutterRoot, 'packages', 'flutter'),
-      options: <String>['--dart-define=dart.vm.product=true', ...soundNullSafetyOptions],
+      options: <String>['--dart-define=dart.vm.product=true'],
       tests: <String>['test_release${path.separator}'],
     );
     // Run profile mode tests (see packages/flutter/test_profile/README.md)
     await _runFlutterTest(
       path.join(flutterRoot, 'packages', 'flutter'),
-      options: <String>['--dart-define=dart.vm.product=false', '--dart-define=dart.vm.profile=true', ...soundNullSafetyOptions],
+      options: <String>['--dart-define=dart.vm.product=false', '--dart-define=dart.vm.profile=true'],
       tests: <String>['test_profile${path.separator}'],
     );
   }
@@ -817,7 +813,7 @@ Future<void> _runFrameworkTests() async {
     for (final String trackWidgetCreationOption in trackWidgetCreationAlternatives) {
       await _runFlutterTest(
         path.join(flutterRoot, 'packages', 'flutter'),
-        options: <String>[trackWidgetCreationOption, ...soundNullSafetyOptions],
+        options: <String>[trackWidgetCreationOption],
         tests: tests,
       );
     }
@@ -837,9 +833,9 @@ Future<void> _runFrameworkTests() async {
         workingDirectory: path.join(flutterRoot, 'examples', 'api'),
       );
     }
-    await _runFlutterTest(path.join(flutterRoot, 'examples', 'api'), options: soundNullSafetyOptions);
-    await _runFlutterTest(path.join(flutterRoot, 'examples', 'hello_world'), options: soundNullSafetyOptions);
-    await _runFlutterTest(path.join(flutterRoot, 'examples', 'layers'), options: soundNullSafetyOptions);
+    await _runFlutterTest(path.join(flutterRoot, 'examples', 'api'));
+    await _runFlutterTest(path.join(flutterRoot, 'examples', 'hello_world'));
+    await _runFlutterTest(path.join(flutterRoot, 'examples', 'layers'));
   }
 
   Future<void> runTracingTests() async {
@@ -945,7 +941,6 @@ Future<void> _runFrameworkTests() async {
 
   Future<void> runPrivateTests() async {
     final List<String> args = <String>[
-      '--sound-null-safety',
       'run',
       'bin/test_private.dart',
     ];
@@ -989,17 +984,17 @@ Future<void> _runFrameworkTests() async {
     await _runFlutterTest(path.join(flutterRoot, 'dev', 'tools', 'gen_defaults'));
     await _runFlutterTest(path.join(flutterRoot, 'dev', 'tools', 'gen_keycodes'));
     await _runFlutterTest(path.join(flutterRoot, 'dev', 'benchmarks', 'test_apps', 'stocks'));
-    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_driver'), tests: <String>[path.join('test', 'src', 'real_tests')], options: soundNullSafetyOptions);
+    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_driver'), tests: <String>[path.join('test', 'src', 'real_tests')]);
     await _runFlutterTest(path.join(flutterRoot, 'packages', 'integration_test'), options: <String>[
       '--enable-vmservice',
       // Web-specific tests depend on Chromium, so they run as part of the web_long_running_tests shard.
       '--exclude-tags=web',
     ]);
-    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_goldens'), options: soundNullSafetyOptions);
-    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_localizations'), options: soundNullSafetyOptions);
-    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_test'), options: soundNullSafetyOptions);
-    await _runFlutterTest(path.join(flutterRoot, 'packages', 'fuchsia_remote_debug_protocol'), options: soundNullSafetyOptions);
-    await _runFlutterTest(path.join(flutterRoot, 'dev', 'integration_tests', 'non_nullable'), options: mixedModeNullSafetyOptions);
+    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_goldens'));
+    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_localizations'));
+    await _runFlutterTest(path.join(flutterRoot, 'packages', 'flutter_test'));
+    await _runFlutterTest(path.join(flutterRoot, 'packages', 'fuchsia_remote_debug_protocol'));
+    await _runFlutterTest(path.join(flutterRoot, 'dev', 'integration_tests', 'non_nullable'));
     const String httpClientWarning =
       'Warning: At least one test in this suite creates an HttpClient. When\n'
       'running a test suite that uses TestWidgetsFlutterBinding, all HTTP\n'
@@ -1234,7 +1229,7 @@ Future<void> _runWebLongRunningTests() async {
         '--dart-define=TEST_FLUTTER_ENGINE_VERSION=$engineVersion',
       ]),
     () => _runWebDebugTest('test/test.dart'),
-    () => _runWebDebugTest('lib/null_safe_main.dart', enableNullSafety: true),
+    () => _runWebDebugTest('lib/null_safe_main.dart'),
     () => _runWebDebugTest('lib/web_define_loading.dart',
       additionalArguments: <String>[
         '--dart-define=test.valueA=Example,A',
@@ -1247,12 +1242,8 @@ Future<void> _runWebLongRunningTests() async {
         '--dart-define=test.valueB=Value',
       ]
     ),
-    () => _runWebDebugTest('lib/sound_mode.dart', additionalArguments: <String>[
-      '--sound-null-safety',
-    ]),
-    () => _runWebReleaseTest('lib/sound_mode.dart', additionalArguments: <String>[
-      '--sound-null-safety',
-    ]),
+    () => _runWebDebugTest('lib/sound_mode.dart'),
+    () => _runWebReleaseTest('lib/sound_mode.dart'),
     () => _runFlutterWebTest(
       'html',
       path.join(flutterRoot, 'packages', 'integration_test'),
@@ -1311,7 +1302,6 @@ Future<void> _runFlutterDriverWebTest({
       if (driver != null) '--driver=$driver',
       '--target=$target',
       '--browser-name=chrome',
-      '--no-sound-null-safety',
       '-d',
       'web-server',
       '--$buildMode',
@@ -1353,7 +1343,6 @@ Future<void> _runWebTreeshakeTest() async {
       'build',
       'web',
       '--target=$target',
-      '--no-sound-null-safety',
       '--profile',
     ],
     workingDirectory: testAppDirectory,
@@ -1579,7 +1568,6 @@ Future<void> _runGalleryE2eWebTest(String buildMode, { bool canvasKit = false })
       '--driver=test_driver/transitions_perf_e2e_test.dart',
       '--target=test_driver/transitions_perf_e2e.dart',
       '--browser-name=chrome',
-      '--no-sound-null-safety',
       '-d',
       'web-server',
       '--$buildMode',
@@ -1686,7 +1674,6 @@ Future<void> _runWebReleaseTest(String target, {
 ///
 /// Instead, we use `flutter run --debug` and sniff out the standard output.
 Future<void> _runWebDebugTest(String target, {
-  bool enableNullSafety = false,
   List<String> additionalArguments = const<String>[],
 }) async {
   final String testAppDirectory = path.join(flutterRoot, 'dev', 'integration_tests', 'web');
@@ -1700,11 +1687,6 @@ Future<void> _runWebDebugTest(String target, {
     <String>[
       'run',
       '--debug',
-      if (enableNullSafety)
-        ...<String>[
-          '--no-sound-null-safety',
-          '--null-assertions',
-        ],
       '-d',
       'chrome',
       '--web-run-headless',
@@ -1747,7 +1729,6 @@ Future<void> _runFlutterWebTest(String webRenderer, String workingDirectory, Lis
       '--platform=chrome',
       '--web-renderer=$webRenderer',
       '--dart-define=DART_HHH_BOT=$_runningInDartHHHBot',
-      '--sound-null-safety',
       ...flutterTestArgs,
       ...tests,
     ],

packages/flutter/test/foundation/isolates_test.dart

@@ -80,8 +80,7 @@ Future<int> test5CallCompute(int value) {
   return compute(test5, value);
 }
 
-Future<void> expectFileSuccessfullyCompletes(String filename,
-    [bool unsound = false]) async {
+Future<void> expectFileSuccessfullyCompletes(String filename) async {
   // Run a Dart script that calls compute().
   // The Dart process will terminate only if the script exits cleanly with
   // all isolate ports closed.
@@ -93,12 +92,10 @@ Future<void> expectFileSuccessfullyCompletes(String filename,
   final String packageRoot = fs.path.dirname(fs.path.fromUri(platform.script));
   final String scriptPath =
       fs.path.join(packageRoot, 'test', 'foundation', filename);
-  final String nullSafetyArg =
-      unsound ? '--no-sound-null-safety' : '--sound-null-safety';
 
   // Enable asserts to also catch potentially invalid assertions.
   final ProcessResult result = await Process.run(
-      dartPath, <String>[nullSafetyArg, 'run', '--enable-asserts', scriptPath]);
+      dartPath, <String>['run', '--enable-asserts', scriptPath]);
   expect(result.exitCode, 0);
 }
 

packages/flutter/test_private/bin/test_private.dart

@@ -225,7 +225,7 @@ class TestCase {
     for (final File test in tests) {
       final String testPath = path.join(path.dirname(test.path), 'lib', path.basenameWithoutExtension(test.path));
       final ProcessRunnerResult result = await runner.runProcess(
-        <String>[flutter, 'test', '--enable-experiment=non-nullable', '--no-sound-null-safety', '--null-assertions', testPath],
+        <String>[flutter, 'test', testPath],
         failOk: true,
       );
       if (result.exitCode != 0) {

packages/flutter_tools/lib/src/globals.dart

@@ -43,6 +43,7 @@ import 'pre_run_validator.dart';
 import 'project.dart';
 import 'reporting/crash_reporting.dart';
 import 'reporting/reporting.dart';
+import 'runner/flutter_command.dart';
 import 'runner/local_engine.dart';
 import 'version.dart';
 
@@ -285,3 +286,7 @@ const String kDefaultFrameworkChannel = 'master';
 
 // Used to build RegExp instances which can detect the VM service message.
 final RegExp kVMServiceMessageRegExp = RegExp(r'The Dart VM service is listening on ((http|//)[a-zA-Z0-9:/=_\-\.\[\]]+)');
+
+// The official tool no longer allows non-null safe builds. This can be
+// overridden in other clients.
+NonNullSafeBuilds get nonNullSafeBuilds => context.get<NonNullSafeBuilds>() ?? NonNullSafeBuilds.notAllowed;

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -21,7 +21,6 @@ import '../bundle.dart' as bundle;
 import '../cache.dart';
 import '../convert.dart';
 import '../dart/generate_synthetic_packages.dart';
-import '../dart/language_version.dart';
 import '../dart/package_map.dart';
 import '../dart/pub.dart';
 import '../device.dart';
@@ -822,20 +821,13 @@ abstract class FlutterCommand extends Command<void> {
 
   void addNullSafetyModeOptions({ required bool hide }) {
     argParser.addFlag(FlutterOptions.kNullSafety,
-      help:
-        'Whether to override the inferred null safety mode. This allows null-safe '
-        'libraries to depend on un-migrated (non-null safe) libraries. By default, '
-        'Flutter mobile & desktop applications will attempt to run at the null safety '
-        'level of their entrypoint library (usually lib/main.dart). Flutter web '
-        'applications will default to sound null-safety, unless specifically configured.',
+      help: 'This flag is deprecated as only null-safe code is supported.',
       defaultsTo: true,
-      hide: hide,
+      hide: true,
     );
     argParser.addFlag(FlutterOptions.kNullAssertions,
-      help:
-        'Perform additional null assertions on the boundaries of migrated and '
-        'un-migrated code. This setting is not currently supported on desktop '
-        'devices.'
+      help: 'This flag is deprecated as only null-safe code is supported.',
+      hide: true,
     );
   }
 
@@ -1148,39 +1140,17 @@ abstract class FlutterCommand extends Command<void> {
 
     NullSafetyMode nullSafetyMode = NullSafetyMode.sound;
     if (argParser.options.containsKey(FlutterOptions.kNullSafety)) {
-      // Explicitly check for `true` and `false` so that `null` results in not
-      // passing a flag. Examine the entrypoint file to determine if it
-      // is opted in or out.
       final bool wasNullSafetyFlagParsed = argResults?.wasParsed(FlutterOptions.kNullSafety) ?? false;
-      if (!wasNullSafetyFlagParsed && (argParser.options.containsKey('target') || forcedTargetFile != null)) {
-        final File entrypointFile = forcedTargetFile ?? globals.fs.file(targetFile);
-        final LanguageVersion languageVersion = determineLanguageVersion(
-          entrypointFile,
-          packageConfig.packageOf(entrypointFile.absolute.uri),
-          Cache.flutterRoot!,
-        );
-        // Extra frontend options are only provided if explicitly
-        // requested.
-        if ((languageVersion.major > nullSafeVersion.major) ||
-            (languageVersion.major == nullSafeVersion.major && languageVersion.minor >= nullSafeVersion.minor)) {
+      // Extra frontend options are only provided if explicitly
+      // requested.
+      if (wasNullSafetyFlagParsed) {
+        if (boolArg(FlutterOptions.kNullSafety)) {
           nullSafetyMode = NullSafetyMode.sound;
+          extraFrontEndOptions.add('--sound-null-safety');
         } else {
-          throwToolExit(
-            'This application does not support sound null-safety (its language version is $languageVersion).\n'
-            'To build this application, you must provide the CLI flag --no-sound-null-safety. Dart 3 will only '
-            'support sound null safety, see https://dart.dev/null-safety.',
-          );
+          nullSafetyMode = NullSafetyMode.unsound;
+          extraFrontEndOptions.add('--no-sound-null-safety');
         }
-      } else if (!wasNullSafetyFlagParsed) {
-        // This mode is only used for commands which do not build a single target like
-        // 'flutter test'.
-        nullSafetyMode = NullSafetyMode.autodetect;
-      } else if (boolArg(FlutterOptions.kNullSafety)) {
-        nullSafetyMode = NullSafetyMode.sound;
-        extraFrontEndOptions.add('--sound-null-safety');
-      } else {
-        nullSafetyMode = NullSafetyMode.unsound;
-        extraFrontEndOptions.add('--no-sound-null-safety');
       }
     }
 
@@ -1487,6 +1457,16 @@ abstract class FlutterCommand extends Command<void> {
   /// rather than calling [runCommand] directly.
   @mustCallSuper
   Future<FlutterCommandResult> verifyThenRunCommand(String? commandPath) async {
+    if (argParser.options.containsKey(FlutterOptions.kNullSafety) &&
+        argResults![FlutterOptions.kNullSafety] == false &&
+        globals.nonNullSafeBuilds == NonNullSafeBuilds.notAllowed) {
+      throwToolExit('''
+Could not find an option named "no-${FlutterOptions.kNullSafety}".
+
+Run 'flutter -h' (or 'flutter <command> -h') for available flutter commands and options.
+''');
+    }
+
     globals.preRunValidator.validate();
 
     if (refreshWirelessDevices) {
@@ -1754,3 +1734,12 @@ DevelopmentArtifact? artifactFromTargetPlatform(TargetPlatform targetPlatform) {
 
 /// Returns true if s is either null, empty or is solely made of whitespace characters (as defined by String.trim).
 bool _isBlank(String s) => s.trim().isEmpty;
+
+/// Whether the tool should allow non-null safe builds.
+///
+/// The Dart SDK no longer supports non-null safe builds, so this value in the
+/// tool's context should always be [NonNullSafeBuilds.notAllowed].
+enum NonNullSafeBuilds {
+  allowed,
+  notAllowed,
+}

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

@@ -67,6 +67,52 @@ void main() {
       Logger: () => BufferLogger.test(),
     });
 
+    testUsingContext('does not support --no-sound-null-safety by default', () async {
+      fileSystem.file('lib/main.dart').createSync(recursive: true);
+      fileSystem.file('pubspec.yaml').createSync();
+      fileSystem.file('.packages').createSync();
+
+      final TestRunCommandThatOnlyValidates command = TestRunCommandThatOnlyValidates();
+      await expectLater(
+        () => createTestCommandRunner(command).run(<String>[
+          'run',
+          '--use-application-binary=app/bar/faz',
+          '--no-sound-null-safety',
+        ]),
+        throwsA(isException.having(
+          (Exception exception) => exception.toString(),
+          'toString',
+          contains('Could not find an option named "no-sound-null-safety"'),
+        )),
+      );
+    }, overrides: <Type, Generator>{
+      FileSystem: () => fileSystem,
+      ProcessManager: () => FakeProcessManager.any(),
+      Logger: () => BufferLogger.test(),
+    });
+
+    testUsingContext('supports --no-sound-null-safety with an overridden NonNullSafeBuilds', () async {
+      fileSystem.file('lib/main.dart').createSync(recursive: true);
+      fileSystem.file('pubspec.yaml').createSync();
+      fileSystem.file('.packages').createSync();
+
+      final FakeDevice device = FakeDevice(isLocalEmulator: true, platformType: PlatformType.android);
+
+      testDeviceManager.devices = <Device>[device];
+      final TestRunCommandThatOnlyValidates command = TestRunCommandThatOnlyValidates();
+      await createTestCommandRunner(command).run(const <String>[
+        'run',
+        '--use-application-binary=app/bar/faz',
+        '--no-sound-null-safety',
+      ]);
+    }, overrides: <Type, Generator>{
+      DeviceManager: () => testDeviceManager,
+      FileSystem: () => fileSystem,
+      Logger: () => BufferLogger.test(),
+      NonNullSafeBuilds: () => NonNullSafeBuilds.allowed,
+      ProcessManager: () => FakeProcessManager.any(),
+    });
+
     testUsingContext('does not support "--use-application-binary" and "--fast-start"', () async {
       fileSystem.file('lib/main.dart').createSync(recursive: true);
       fileSystem.file('pubspec.yaml').createSync();

packages/flutter_tools/test/general.shard/args_test.dart

@@ -176,7 +176,10 @@ void verifyOptions(String? command, Iterable<Option> options) {
       expect(option.name, matches(_allowedArgumentNamePattern), reason: '$_header$target--${option.name}" is not a valid name for a command line argument. (Is it all lowercase? Does it use hyphens rather than underscores?)');
     }
     expect(option.name, isNot(matches(_bannedArgumentNamePattern)), reason: '$_header$target--${option.name}" is not a valid name for a command line argument. (We use "--foo-url", not "--foo-uri", for example.)');
-    expect(option.hide, isFalse, reason: '${_header}Help for $target--${option.name}" is always hidden. $_needHelp');
+    // The flag --sound-null-safety is deprecated
+    if (option.name != FlutterOptions.kNullSafety && option.name != FlutterOptions.kNullAssertions) {
+      expect(option.hide, isFalse, reason: '${_header}Help for $target--${option.name}" is always hidden. $_needHelp');
+    }
     expect(option.help, isNotNull, reason: '${_header}Help for $target--${option.name}" has null help. $_needHelp');
     expect(option.help, isNotEmpty, reason: '${_header}Help for $target--${option.name}" has empty help. $_needHelp');
     expect(option.help, isNot(matches(_bannedLeadingPatterns)), reason: '${_header}A line in the help for $target--${option.name}" starts with a lowercase letter. For stylistic consistency, all help messages must start with a capital letter.');