Node.js プロジェクトの設定 - TypeScript & ESLint & Prettier

December 14, 2021

最近使いまわしている設定ファイルの内容を自分用に記録。

前提：Node.js 14 を想定しています。

パッケージインストール #

今回の構成に必要なパッケージをインストールするには以下を実行。

npm i -D \
  typescript \
  prettier \
  eslint \
  @typescript-eslint/parser \
  @typescript-eslint/eslint-plugin \
  eslint-config-airbnb-base \
  eslint-config-airbnb-typescript \
  eslint-config-prettier \
  eslint-plugin-import

TypeScript 関連 #

tsconfig.json

{
  "compilerOptions": {
    "outDir": "lib",
    "target": "es2020", // Node.js 14
    "module": "commonjs",
    "lib": ["es2020"], // Node.js 14
    "sourceMap": true,
    "removeComments": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "esModuleInterop": true,
    "resolveJsonModule": true,
    "strict": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitReturns": true,
    "noImplicitOverride": true
  },
  "exclude": ["node_modules", "lib"],
  "include": ["src"]
}

参考：設定値の一覧

https://www.typescriptlang.org/tsconfig

tsconfig.eslint.json

{
  "extends": "./tsconfig.json",
  "include": ["**/*.js", "**/*.jsx", "**/*.ts", "**/*.tsx"]
}

ESLint 関連 #

.eslintrc.json

{
  "root": true,
  "env": {
    "node": true,
    "es2020": true
  },
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "project": ["./tsconfig.eslint.json"],
    "sourceType": "module",
    "ecmaVersion": 2020
  },
  "plugins": ["@typescript-eslint", "import"],
  "extends": [
    "airbnb-base",
    "airbnb-typescript/base",
    "eslint:recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:@typescript-eslint/recommended-requiring-type-checking",
    "plugin:import/recommended",
    "plugin:import/typescript",
    "prettier"
  ],
  "rules": {
    "@typescript-eslint/ban-ts-comment": "off",
    "@typescript-eslint/no-use-before-define": "off",
    "@typescript-eslint/no-unused-vars": ["error", { "argsIgnorePattern": "^_" }],
    "@typescript-eslint/consistent-type-assertions": [
      "error",
      { "assertionStyle": "as", "objectLiteralTypeAssertions": "never" }
    ],
    "@typescript-eslint/consistent-type-definitions": ["error", "type"],
    "@typescript-eslint/consistent-type-imports": "error",
    "import/prefer-default-export": "off",
    "import/exports-last": "error",
    "import/order": [
      "error",
      {
        "groups": [
          "builtin",
          "external",
          "internal",
          "parent",
          "sibling",
          "index",
          "object",
          "type"
        ],
        "alphabetize": { "order": "asc" },
        "newlines-between": "never"
      }
    ],
    "sort-imports": ["error", { "ignoreDeclarationSort": true, "ignoreMemberSort": false }],
    "arrow-body-style": "off"
  }
}

参考：プリセットの内容

airbnb-base
- https://github.com/airbnb/javascript/tree/master/packages/eslint-config-airbnb
eslint:recommended
- https://eslint.org/docs/rules/
@typescript-eslint/recommended
- https://github.com/typescript-eslint/typescript-eslint/tree/main/packages/eslint-plugin
import/recommended
- https://github.com/import-js/eslint-plugin-import

.eslintignore

node_modules/
lib/

参考：書き方の例

Prettier 関連 #

.prettierrc.json

{
  "printWidth": 100,
  "singleQuote": true,
  "trailingComma": "all"
}

参考：設定値の一覧

https://prettier.io/docs/en/options.html

.prettierignore

node_modules/
lib/

参考：書き方の例

package.json 関連 #

package.json

engines の明示と scripts のフィールドにリント実行用のコマンドを追加

{
  "engines": {
    "node": "14"
  },
  "scripts": {
    "lint:tsc": "tsc --noEmit",
    "lint:eslint": "eslint src --ext .js,.jsx,.ts,.tsx",
    "fix:eslint": "eslint src --ext .js,.jsx,.ts,.tsx --fix",
    "lint:prettier": "prettier --check src",
    "fix:prettier": "prettier --write src",
    "lint:all": "npm run lint:tsc && npm run lint:eslint && npm run lint:prettier"
  }
}