✂️
very_good_analysisを使ってみる!
📕Overview
このパッケージは、Very Good Ventures で使用される Dart と Flutter の lint ルールを提供します。詳細については、オプションの完全なリストを参照してください。
lint を使用するには、pubspec.yaml に開発依存関係として追加します。
dev_dependenciesの下に追加する。
pubspec.yamlの設定
name: very_good_analysis_example
description: "A new Flutter project."
# The following line prevents the package from being accidentally published to
# pub.dev using `flutter pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev
# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number is used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
# In Windows, build-name is used as the major, minor, and patch parts
# of the product and file versions while build-number is used as the build suffix.
version: 1.0.0+1
environment:
sdk: '>=3.3.0 <4.0.0'
# Dependencies specify other packages that your package needs in order to work.
# To automatically upgrade your package dependencies to the latest versions
# consider running `flutter pub upgrade --major-versions`. Alternatively,
# dependencies can be manually updated by changing the version numbers below to
# the latest version available on pub.dev. To see which dependencies have newer
# versions available, run `flutter pub outdated`.
dependencies:
flutter:
sdk: flutter
# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^1.0.6
dev_dependencies:
flutter_test:
sdk: flutter
very_good_analysis: ^5.1.0 # ここについか
# The "flutter_lints" package below contains a set of recommended lints to
# encourage good coding practices. The lint set provided by the package is
# activated in the `analysis_options.yaml` file located at the root of your
# package. See that file for information about deactivating specific lint
# rules and activating additional ones.
flutter_lints: ^3.0.0
# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec
# The following section is specific to Flutter packages.
flutter:
# The following line ensures that the Material Icons font is
# included with your application, so that you can use the icons in
# the material Icons class.
uses-material-design: true
# To add assets to your application, add an assets section, like this:
# assets:
# - images/a_dot_burr.jpeg
# - images/a_dot_ham.jpeg
# An image asset can refer to one or more resolution-specific "variants", see
# https://flutter.dev/assets-and-images/#resolution-aware
# For details regarding adding assets from package dependencies, see
# https://flutter.dev/assets-and-images/#from-packages
# To add custom fonts to your application, add a fonts section here,
# in this "flutter" section. Each entry in this list should have a
# "family" key with the font family name, and a "fonts" key with a
# list giving the asset and other descriptors for the font. For
# example:
# fonts:
# - family: Schyler
# fonts:
# - asset: fonts/Schyler-Regular.ttf
# - asset: fonts/Schyler-Italic.ttf
# style: italic
# - family: Trajan Pro
# fonts:
# - asset: fonts/TrajanPro.ttf
# - asset: fonts/TrajanPro_Bold.ttf
# weight: 700
#
# For details regarding fonts from package dependencies,
# see https://flutter.dev/custom-fonts/#from-packages
次に、analyze_options.yaml にインクルードを追加します。
[これに変更するだけ]
include: package:very_good_analysis/analysis_options.yaml
analysis_options.yamlを設定
# This file configures the analyzer, which statically analyzes Dart code to
# check for errors, warnings, and lints.
#
# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
# invoked from the command line by running `flutter analyze`.
# The following line activates a set of recommended lints for Flutter apps,
# packages, and plugins designed to encourage good coding practices.
#include: package:flutter_lints/flutter.yaml 元の設定
include: package:very_good_analysis/analysis_options.yaml # これに変更
linter:
# The lint rules applied to this project can be customized in the
# section below to disable rules from the `package:flutter_lints/flutter.yaml`
# included above or to enable additional rules. A list of all available lints
# and their documentation is published at https://dart.dev/lints.
#
# Instead of disabling a lint rule for the entire project in the
# section below, it can also be suppressed for a single line of code
# or a specific dart file by using the `// ignore: name_of_lint` and
# `// ignore_for_file: name_of_lint` syntax on the line or in the file
# producing the lint.
rules:
# avoid_print: false # Uncomment to disable the `avoid_print` rule
# prefer_single_quotes: true # Uncomment to enable the `prefer_single_quotes` rule
# Additional information about this file can be found at
# https://dart.dev/guides/language/analysis-options
🧷summary
Lintを導入するとコードの書き方のルールが強制されます。どのようなコードを書いてはいけないルールが適用されたのか見ていきましょう。
デフォルトのカウンタアプリのコード
main.dart
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
useMaterial3: true,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({
required this.title,
super.key,
});
final String title;
void logFunc({
required String age,
String? name,
}) {
print('Name: $name, Age: $age');
}
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headlineMedium,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
),
);
}
}
requiredキーワードがついていると、先頭に配置しないと警告が出るみたいです。Android Studioだと元々厳しいのかVSCodeよりニョロニョロ出てきますね💦
先頭にしたら、他の部分のLintの警告は消えましたね。
ああでもこれ追加したら消えましたね。
// ignore_for_file: public_member_api_docs
[Android Studio]
[VScode]
@immutableをつけないで、hashCodeを使ってはダメらしい!
The method 'hashCode' should not be overridden in classes not annotated with '@immutable'. (Documentation) Try removing the override or annotating the class with '@immutable'.
メソッド「hashCode」は、「@immutable」の注釈が付けられていないクラスではオーバーライドしないでください。 (ドキュメント) オーバーライドを削除するか、クラスに「@immutable」の注釈を付けてください。
[つけてない状態]
[つけた後]
🧑🎓thoughts
pedantic_monoを使ってみたことあるのですが、very_good_analysisはもっとルールが厳しいそうです。普段は私Lintなんて使ってなくて、Flutter3標準の最近厳しくなったルールをそのまま使ってるだけですね🌱
今回は、設定方法と実際に使ってみた感想を記事にしてみました。こちらのブログ参考になりました。ご興味ある方は試してみてください。
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