.eslintrc.json

{
  "parser": "@typescript-eslint/parser",
  "env": {
    "browser": true,
    "node": true,
    "es6": true,
    "jest": true
  },
  "parserOptions": {
    "ecmaVersion": 2020,
    "sourceType": "module",
    "extraFileExtensions": [".mjs"],
    "ecmaFeatures": {
      "impliedStrict": true,
      "jsx": true
    },
    "project": "./tsconfig.json"
  },
  "extends": [
    "react-app",
    "react-app/jest",
    "plugin:unicorn/recommended",
    "plugin:prettier/recommended"
  ],
  "plugins": ["react", "jsx-a11y", "import", "prettier", "unicorn"],
  "settings": {
    "react": { "version": "detect" },
    "import/resolver": { "typescript": {} }
  },
  "rules": {
    // React is imported in the entrypoint or _app.js
    "react/react-in-jsx-scope": "off",
    // Allow JSX in typescript files
    "react/jsx-filename-extension": [1, { "extensions": [".js", ".jsx", ".tsx"] }],
    // Frameworks like Next and Flareact have specific Link components
    "jsx-a11y/anchor-is-valid": [
      "error",
      {
        "components": ["Link"],
        "specialLink": ["hrefLeft", "hrefRight"],
        "aspects": ["invalidHref", "preferButton"]
      }
    ],
    // Some abbreviations are (or will soon be) clear even for new programmers
    "unicorn/prevent-abbreviations": [
      "error",
      {
        "replacements": {
          "props": { "properties": false },
          "ref": { "reference": false },
          "env": { "environment": false },
          "fn": { "function": false }
        }
      }
    ],
    // Waiting for AirBnb upgrade: https://github.com/typescript-eslint/typescript-eslint/issues/2077#issuecomment-634811363
    "@typescript-eslint/camelcase": "off",
    // Conflict between prettier and eslint-unicorn
    "react/jsx-wrap-multilines": "off",
    // Allow forOfStatements
    "no-restricted-syntax": ["error", "ForInStatement", "LabeledStatement", "WithStatement"],
    // Continue is viable in forOf loops in generators
    "no-continue": "off",
    // Spreading is needed in case of forwarding props
    "react/jsx-props-no-spreading": "off",
    // Allow inline <strong> tags
    "react/jsx-one-expression-per-line": "off",
    // React components should be able to return null
    "unicorn/no-null": "off",
    // Redux and Immer use prop reassign by design
    "no-param-reassign": ["error", { "props": false }],
    // For react components it's not always useful to move small methods up in scope
    "unicorn/consistent-function-scoping": ["error", { "checkArrowFunctions": false }],
    // From experience, named exports are almost always desired. I got tired of this rule
    "import/prefer-default-export": "off",
    // Firebase requires importing each module that's used
    "import/no-duplicates": "off",
    // Unused vars are useful to keep method signatures consistent and documented
    "@typescript-eslint/no-unused-vars": "off",
    // Found false positive, not correctly detecting try catch, then autofixed and broke some code
    "@typescript-eslint/return-await": "off",
    // For this project don't use kebab-case
    "unicorn/filename-case": [
      "error",
      {
        "cases": {
          "camelCase": true,
          "pascalCase": true
        },
        "ignore": [".d.ts"]
      }
    ],
    // in typescript having fn({}: Props) is very useful for boilerplate
    "no-empty-pattern": "off",
    // Allow Array.from(set) mitigate TS2569 which would require '--downlevelIteration'
    "unicorn/prefer-spread": "off"
  }
}