日. 6月 26th, 2022

コードフォーマッターとしての Prettier (プリティア)をプロジェクトに組み込む方法を紹介。

また、2021 年に静的検証ツールとしての ESLintがPrettierが merge され、今までは別々にインストールする必要があったが、 Prettier のみインストールすればよくなった。

“prettier/@typescript-eslint” has been merged into “prettier” in eslint-config-prettier 8.0.0. See: https://github.com/prettier/eslint-config-prettier/blob/main/CHANGELOG.md#version-800-2021-02-21

Prettier

インストール方法は以下の通り

npm install -D prettier eslint-config-prettier eslint-plugin-prettier

npm init @eslint/config


Ok to proceed? (y) y
✔ How would you like to use ESLint? · problems
✔ What type of modules does your project use? · esm
✔ Which framework does your project use? · none
✔ Does your project use TypeScript? · No / Yes
✔ Where does your code run? · browser
✔ What format do you want your config file to be in? · JavaScript
The config that you've selected requires the following dependencies:

@typescript-eslint/eslint-plugin@latest @typescript-eslint/parser@latest
✔ Would you like to install them now with npm? · No / Yes
Installing @typescript-eslint/eslint-plugin@latest, @typescript-eslint/parser@latest

removed 7 packages, and audited 858 packages in 4s

47 packages are looking for funding
  run `npm fund` for details

1 critical severity vulnerability

To address all issues, run:
  npm audit fix

Run `npm audit` for details.
A config file was generated, but the config file itself may not follow your linting rules.
Successfully created .eslintrc.js file in /Users/sumito.tsukada/go/src/git.rarejob.com/rarejob-platform/account-web/aws/rjpf-student-account-web-alb-ecsc-ecr-cdeploy

プロジェクト直下に js を配置

vi .prettierrc.js
module.exports = {
    singleQuote: true, 
    tabWidth: 4, 
    trailingComma: 'es5', 
};

package.json を一部修正

     "build": "tsc",
     "watch": "tsc -w",
     "test": "jest",
-    "cdk": "cdk"
+    "cdk": "cdk",
+    "lint": "eslint --ext .ts ."
   },
   "devDependencies": {
     "@aws-cdk/assertions": "1.135.0",

警告

 npm run lint

> sample@0.1.0 lint
> eslint --ext .ts .


sample.test.ts
  1:20  warning  'Match' is defined but never used  @typescript-eslint/no-unused-vars

✖ 1 problem (0 errors, 1 warning)