ESlint for TypeScript

Based on video course [FrontendMasters] Production-Grade TypeScript

Configured project :
https://github.com/mike-north/professional-ts-my-lib

$ yarn add --dev \
    @typescript-eslint/eslint-plugin \
    @typescript-eslint/parser \
    eslint

// Generate eslint config if needed
// $ ./node_modules/.bin/eslint --init

.eslintrc.json

$ vi .eslintrc.json

{
  "env": { "node": true },
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "ecmaVersion": 2020,
    "project": "tsconfig.eslint.json"
  },
  "extends": [
    "eslint:recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:@typescript-eslint/recommended-requiring-type-checking"
  ],
  "plugins": ["@typescript-eslint"],
  "rules": {
    "prefer-const": "error",
    "@typscript-eslint/no-unused-vars": "off",
    "@typscript-eslint/no-unused-params": "off"
  },
  "overrides": [
    {
      "files": ["tests/**/*.ts"],
      "env": { "jest": true, "node": true }
    }
  ]
}

no-unused-vars, no-unused-params - are specified in tsconfig already

tsconfig.eslint.json

$ vi tsconfig.eslint.json

{
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "types": ["jest"]
  },
  "include": ["src", "tests"]
}

.eslintignore

$ vi .eslintignore

/node_modules/
/build/

// Check
$ npx eslint src/

ESLint Plugin TypeScript
https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/README.md