feat(bloc_lint): add prefer_bloc_provider

docs/src/components/lint-rules/prefer_bloc_provider/BadSnippet.mdx

@@ -0,0 +1,23 @@
+import { Code } from '@astrojs/starlight/components';
+import { transformerMetaHighlight } from '@shikijs/transformers';
+
+<Code
+	code={`
+  import 'package:flutter/material.dart';
+  import 'package:provider/provider.dart';
+
+  class CounterPage extends StatelessWidget {
+    const CounterPage({super.key});
+
+    @override
+    Widget build(BuildContext context) {
+      return Provider<CounterBloc>(
+        create: (_) => CounterBloc(),
+        child: const CounterView(),
+      );
+    }
+  }
+`}
+lang="dart" title="counter_page.dart"
+transformers={[transformerMetaHighlight()]} class='warning' meta="{9}"
+/>

docs/src/components/lint-rules/prefer_bloc_provider/GoodSnippet.astro

@@ -0,0 +1,22 @@
+---
+import { Code } from '@astrojs/starlight/components';
+
+const code = `
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+class CounterPage extends StatelessWidget {
+  const CounterPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return BlocProvider(
+      create: (_) => CounterBloc(),
+      child: const CounterView(),
+    );
+  }
+}
+`;
+---
+
+<Code code={code} lang="dart" title="counter_page.dart" />

docs/src/content/docs/lint-rules/prefer_bloc_provider.mdx

@@ -0,0 +1,48 @@
+---
+title: Prefer Bloc Provider
+description: The prefer_bloc_provider rule.
+---
+
+import { Badge } from '@astrojs/starlight/components';
+import EnableRuleSnippet from '~/components/lint-rules/EnableRuleSnippet.astro';
+import BadSnippet from '~/components/lint-rules/prefer_bloc_provider/BadSnippet.mdx';
+import GoodSnippet from '~/components/lint-rules/prefer_bloc_provider/GoodSnippet.astro';
+
+<div class="badges">
+	<Badge text="new" />
+	<Badge text="dart" variant="note" />
+</div>
+
+Prefer using `BlocProvider` to provide `Bloc` or `Cubit` instances.
+
+:::note
+
+This lint rule was introduced in version `0.4.3` of
+[`package:bloc_lint`](https://pub.dev/packages/bloc_lint)
+
+:::
+
+## Rationale
+
+`BlocProvider` is the intended API for providing `Bloc` and `Cubit` instances.
+Unlike `Provider`, it automatically closes the instance when it is no longer
+needed.
+
+## Examples
+
+**Avoid** using `Provider<T>` when `T` is a `Bloc` or `Cubit`.
+
+**BAD**:
+
+<BadSnippet />
+
+**GOOD**:
+
+<GoodSnippet />
+
+## Enable
+
+To enable the `prefer_bloc_provider` rule, add it to your
+`analysis_options.yaml` under `bloc` > `rules`:
+
+<EnableRuleSnippet name="prefer_bloc_provider" />

packages/bloc_lint/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.4.3
+
+- feat: add [prefer_bloc_provider](https://bloclibrary.dev/lint-rules/prefer_bloc_provider)
+
 # 0.4.2
 
 - deps: adjust bounds for `_fe_analyzer_shared`

packages/bloc_lint/README.md

@@ -91,6 +91,7 @@ For more information, check out the [official documentation](https://bloclibrary
 - [avoid_flutter_imports](https://bloclibrary.dev/lint-rules/avoid_flutter_imports)
 - [avoid_public_bloc_methods](https://bloclibrary.dev/lint-rules/avoid_public_bloc_methods)
 - [avoid_public_fields](https://bloclibrary.dev/lint-rules/avoid_public_fields)
+- [prefer_bloc_provider](https://bloclibrary.dev/lint-rules/prefer_bloc_provider)
 - [prefer_file_naming_conventions](https://bloclibrary.dev/lint-rules/prefer_file_naming_conventions)
 - [prefer_void_public_cubit_methods](https://bloclibrary.dev/lint-rules/prefer_void_public_cubit_methods)
 
@@ -101,6 +102,7 @@ For more information, check out the [official documentation](https://bloclibrary
 - [avoid_public_bloc_methods](https://bloclibrary.dev/lint-rules/avoid_public_bloc_methods)
 - [avoid_public_fields](https://bloclibrary.dev/lint-rules/avoid_public_fields)
 - [prefer_bloc](https://bloclibrary.dev/lint-rules/prefer_bloc)
+- [prefer_bloc_provider](https://bloclibrary.dev/lint-rules/prefer_bloc_provider)
 - [prefer_build_context_extensions](https://bloclibrary.dev/lint-rules/prefer_build_context_extensions)
 - [prefer_cubit](https://bloclibrary.dev/lint-rules/prefer_cubit)
 - [prefer_file_naming_conventions](https://bloclibrary.dev/lint-rules/prefer_file_naming_conventions)

packages/bloc_lint/lib/all.yaml

@@ -5,6 +5,7 @@ bloc:
     - avoid_public_bloc_methods
     - avoid_public_fields
     - prefer_bloc
+    - prefer_bloc_provider
     - prefer_build_context_extensions
     - prefer_cubit
     - prefer_file_naming_conventions

packages/bloc_lint/lib/bloc_lint.dart

@@ -13,6 +13,7 @@ export 'src/rules/rules.dart'
         AvoidPublicBlocMethods,
         AvoidPublicFields,
         PreferBloc,
+        PreferBlocProvider,
         PreferBuildContextExtensions,
         PreferCubit,
         PreferFileNamingConventions,

packages/bloc_lint/lib/recommended.yaml

@@ -3,5 +3,6 @@ bloc:
     - avoid_flutter_imports
     - avoid_public_bloc_methods
     - avoid_public_fields
+    - prefer_bloc_provider
     - prefer_file_naming_conventions
     - prefer_void_public_cubit_methods

packages/bloc_lint/lib/src/linter.dart

@@ -26,6 +26,7 @@ final allRules = <String, LintRuleBuilder>{
   AvoidPublicBlocMethods.rule: AvoidPublicBlocMethods.new,
   AvoidPublicFields.rule: AvoidPublicFields.new,
   PreferBloc.rule: PreferBloc.new,
+  PreferBlocProvider.rule: PreferBlocProvider.new,
   PreferBuildContextExtensions.rule: PreferBuildContextExtensions.new,
   PreferCubit.rule: PreferCubit.new,
   PreferFileNamingConventions.rule: PreferFileNamingConventions.new,

packages/bloc_lint/lib/src/rules/prefer_bloc_provider.dart

@@ -0,0 +1,59 @@
+import 'package:bloc_lint/bloc_lint.dart';
+
+/// {@template prefer_bloc_provider}
+/// The prefer_bloc_provider lint rule.
+/// {@endtemplate}
+class PreferBlocProvider extends LintRule {
+  /// {@macro prefer_bloc_provider}
+  PreferBlocProvider([Severity? severity])
+    : super(name: rule, severity: severity ?? Severity.warning);
+
+  /// The name of the lint rule.
+  static const rule = 'prefer_bloc_provider';
+
+  @override
+  Listener create(LintContext context) => _Listener(context);
+}
+
+class _Listener extends Listener {
+  _Listener(this.context);
+
+  final LintContext context;
+
+  @override
+  void handleIdentifier(Token token, IdentifierContext _) {
+    if (token.lexeme != 'Provider') return;
+
+    final typeArgument = _typeArgumentName(token);
+    if (typeArgument == null) return;
+    if (!_looksLikeBlocBase(typeArgument.lexeme)) return;
+
+    context.reportToken(
+      token: token,
+      message: 'Avoid using Provider to provide bloc or cubit instances.',
+      hint: 'Prefer using BlocProvider instead.',
+    );
+  }
+
+  Token? _typeArgumentName(Token provider) {
+    final lt = provider.next;
+    if (lt == null || lt.type != TokenType.LT) return null;
+
+    var type = lt.next;
+    if (type == null) return null;
+
+    // Skip import prefix: counter.CounterBloc
+    if (type.next?.type == TokenType.PERIOD) {
+      type = type.next!.next;
+      if (type == null) return null;
+    }
+
+    return type;
+  }
+
+  bool _looksLikeBlocBase(String name) {
+    return name.endsWith('BlocBase') ||
+        name.endsWith('Bloc') ||
+        name.endsWith('Cubit');
+  }
+}

packages/bloc_lint/lib/src/rules/rules.dart

@@ -3,6 +3,7 @@ export 'avoid_flutter_imports.dart';
 export 'avoid_public_bloc_methods.dart';
 export 'avoid_public_fields.dart';
 export 'prefer_bloc.dart';
+export 'prefer_bloc_provider.dart';
 export 'prefer_build_context_extensions.dart';
 export 'prefer_cubit.dart';
 export 'prefer_file_naming_conventions.dart';

packages/bloc_lint/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bloc_lint
 description: Official lint rules for development when using the bloc state management library.
-version: 0.4.2
+version: 0.4.3
 repository: https://github.com/felangel/bloc/tree/master/packages/bloc_lint
 issue_tracker: https://github.com/felangel/bloc/issues
 homepage: https://github.com/felangel/bloc