remove Flags (#45320)

packages/flutter_tools/lib/src/base/flags.dart

-// Copyright 2017 The Chromium 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 'package:args/args.dart';
-
-import 'context.dart';
-
-/// command-line flags and options that were specified during the invocation of
-/// the Flutter tool.
-Flags get flags => context.get<Flags>();
-
-/// Encapsulation of the command-line flags and options that were specified
-/// during the invocation of the Flutter tool.
-///
-/// An instance of this class is set into the [AppContext] upon invocation of
-/// the Flutter tool (immediately after the arguments have been parsed in
-/// [FlutterCommandRunner]) and is available via the [flags] global property.
-class Flags {
-  Flags(this._globalResults)
-    : assert(_globalResults != null);
-
-  final ArgResults _globalResults;
-
-  /// Gets the value of the specified command-line flag/option that was set
-  /// during the invocation of the Flutter tool.
-  ///
-  /// This will first search for flags that are specific to the command and will
-  /// fall back to global flags.
-  ///
-  /// If a flag has a default value and the user did not explicitly specify a
-  /// value on the command-line, this will return the default value.
-  ///
-  /// If the specified flag is not defined or was not specified and had no
-  /// default, then this will return `null`.
-  dynamic operator [](String key) {
-    final ArgResults commandResults = _globalResults.command;
-    final Iterable<String> options = commandResults?.options;
-    if (options != null && options.contains(key)) {
-      return commandResults[key];
-    } else if (_globalResults.options.contains(key)) {
-      return _globalResults[key];
-    }
-    return null;
-  }
-
-  /// `true` iff the given flag/option was either explicitly specified by the
-  /// user at the command-line or it was defined to have a default value.
-  bool contains(String key) {
-    final ArgResults commandResults = _globalResults.command;
-    final Iterable<String> options = commandResults?.options;
-    return (options != null && options.contains(key)) || _globalResults.options.contains(key);
-  }
-}
-
-class EmptyFlags implements Flags {
-  const EmptyFlags();
-
-  @override
-  ArgResults get _globalResults => null;
-
-  @override
-  String operator [](String key) => null;
-
-  @override
-  bool contains(String key) => false;
-}

packages/flutter_tools/lib/src/context_runner.dart

@@ -14,7 +14,6 @@ import 'asset.dart';
 import 'base/build.dart';
 import 'base/config.dart';
 import 'base/context.dart';
-import 'base/flags.dart';
 import 'base/io.dart';
 import 'base/logger.dart';
 import 'base/os.dart';
@@ -88,7 +87,6 @@ Future<T> runInContext<T>(
       DoctorValidatorsProvider: () => DoctorValidatorsProvider.defaultInstance,
       EmulatorManager: () => EmulatorManager(),
       FeatureFlags: () => const FeatureFlags(),
-      Flags: () => const EmptyFlags(),
       FlutterVersion: () => FlutterVersion(const SystemClock()),
       FuchsiaArtifacts: () => FuchsiaArtifacts.find(),
       FuchsiaDeviceTools: () => FuchsiaDeviceTools(),

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

@@ -15,7 +15,6 @@ import '../artifacts.dart';
 import '../base/common.dart';
 import '../base/context.dart';
 import '../base/file_system.dart';
-import '../base/flags.dart';
 import '../base/io.dart' as io;
 import '../base/logger.dart';
 import '../base/os.dart';
@@ -253,9 +252,7 @@ class FlutterCommandRunner extends CommandRunner<void> {
 
   @override
   Future<void> runCommand(ArgResults topLevelResults) async {
-    final Map<Type, dynamic> contextOverrides = <Type, dynamic>{
-      Flags: Flags(topLevelResults),
-    };
+    final Map<Type, dynamic> contextOverrides = <Type, dynamic>{};
 
     // Check for verbose.
     if (topLevelResults['verbose'] as bool) {

packages/flutter_tools/test/general.shard/base/flags_test.dart

-// Copyright 2017 The Chromium 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:async';
-
-import 'package:flutter_tools/src/base/flags.dart';
-import 'package:flutter_tools/src/cache.dart';
-import 'package:flutter_tools/src/runner/flutter_command.dart';
-
-import '../../src/common.dart';
-import '../../src/context.dart';
-
-typedef _TestMethod = FutureOr<void> Function();
-
-void main() {
-  Cache.disableLocking();
-
-  Future<void> runCommand(Iterable<String> flags, _TestMethod testMethod) async {
-    final List<String> args = <String>['test', ...flags];
-    final _TestCommand command = _TestCommand(testMethod);
-    await createTestCommandRunner(command).run(args);
-  }
-
-  testUsingContext('runCommand works as expected', () async {
-    bool testRan = false;
-    await runCommand(<String>[], () {
-      testRan = true;
-    });
-    expect(testRan, isTrue);
-  });
-
-  group('flags', () {
-    testUsingContext('returns null for undefined flags', () async {
-      await runCommand(<String>[], () {
-        expect(flags['undefined-flag'], isNull);
-      });
-    });
-
-    testUsingContext('picks up default values', () async {
-      await runCommand(<String>[], () {
-        expect(flags['verbose'], isFalse);
-        expect(flags['flag-defaults-to-false'], isFalse);
-        expect(flags['flag-defaults-to-true'], isTrue);
-        expect(flags['option-defaults-to-foo'], 'foo');
-      });
-    });
-
-    testUsingContext('returns null for flags with no default values', () async {
-      await runCommand(<String>[], () {
-        expect(flags['device-id'], isNull);
-        expect(flags['option-no-default'], isNull);
-      });
-    });
-
-    testUsingContext('picks up explicit values', () async {
-      await runCommand(<String>[
-        '--verbose',
-        '--flag-defaults-to-false',
-        '--option-no-default=explicit',
-        '--option-defaults-to-foo=qux',
-      ], () {
-        expect(flags['verbose'], isTrue);
-        expect(flags['flag-defaults-to-false'], isTrue);
-        expect(flags['option-no-default'], 'explicit');
-        expect(flags['option-defaults-to-foo'], 'qux');
-      });
-    });
-  });
-}
-
-class _TestCommand extends FlutterCommand {
-  _TestCommand(this.testMethod) {
-    argParser.addFlag('flag-defaults-to-false', defaultsTo: false);
-    argParser.addFlag('flag-defaults-to-true', defaultsTo: true);
-    argParser.addOption('option-no-default');
-    argParser.addOption('option-defaults-to-foo', defaultsTo: 'foo');
-  }
-
-  final _TestMethod testMethod;
-
-  @override
-  String get name => 'test';
-
-  @override
-  String get description => 'runs a test method';
-
-  @override
-  Future<FlutterCommandResult> runCommand() async {
-    await testMethod();
-    return null;
-  }
-}