.eslintrc.json

{
  "env": {
    "browser": true,
    "jest": true,
    "es6": true,
    "node": true
  },
  "extends": [
    // "airbnb",
    "eslint:recommended",
    "plugin:react/recommended",
    "plugin:prettier/recommended"
  ],
  "globals": {
    "Atomics": "readonly",
    "SharedArrayBuffer": "readonly"
  },
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "ecmaFeatures": {
      "jsx": true
    },
    "ecmaVersion": 2018,
    "sourceType": "module",
    "project": "./tsconfig.json"
  },
  "plugins": ["@typescript-eslint", "react", "import", "unused-imports"],
  "rules": {
    "react/jsx-filename-extension": [1, { "extensions": [".ts", ".tsx"] }],
    "import/extensions": 0,
    // "unused-imports/no-unused-imports-ts": "error",
    "no-unused-vars": "off",
    "@typescript-eslint/no-unused-vars": [
      "warn",
      { "argsIgnorePattern": "^_" }
    ], // TypeScript用のno-unused-varsを有効にしている。
    "no-console": ["warn", { "allow": ["log", "error"] }], // 本番はlogをallowから消して，no-consoleにする
    "react/prop-types": "off", // TypeScriptではprop-types不要。というかoffらないとlintに引っかかる
    "linebreak-style": [2, "unix"] // 改行コードはLFにそろえる
  },
  "settings": {
    "react": {
      "version": "detect" // デフォルトっぽい設定だけど入れないとwarningが出た。。。どこか間違ったのだろうか。。。
    },
    "import/parsers": {
      "@typescript-eslint/parser": [".ts", ".tsx"]
    },
    "import/resolver": {
      // use <root>/tsconfig.json
      "typescript": {
        "alwaysTryTypes": true, // always try to resolve types under `<roo/>@types` directory even it doesn't contain any source code, like `@types/unist`
        "directory": "./tsconfig.json"
      }
    }
  }
}