.eslintrc.json

{
  "env": {
    "es2021": true,
    "node": true
  },
  "extends": [
    "airbnb-base",
    "plugin:import/recommended",
    "plugin:import/typescript",
    "plugin:prettier/recommended",
    "eslint:recommended"
  ],
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "ecmaVersion": "latest",
    "sourceType": "module"
  },
  "plugins": ["@typescript-eslint", "prettier", "import", "jest"],
  "rules": {
    "import/extensions": "off",
    "max-len": [
      "error",
      {
        "code": 120,
        "tabWidth": 2,
        "ignoreComments": true,
        "ignoreUrls": true
      }
    ],
    "prettier/prettier": "error",
    "@typescript-eslint/explicit-function-return-type": ["error"],
    "@typescript-eslint/consistent-type-imports": ["error"]
  },
  "overrides": [
    {
      "files": ["*.js"],
      "rules": {
        "@typescript-eslint/explicit-function-return-type": "off"
      }
    },
    {
      "files": ["rollup.*.ts", "gulpfile.ts", "gulp/**/*.ts", "config/**/*.ts"],
      "rules": {
        "import/no-extraneous-dependencies": 0
      }
    },
    {
      "files": ["*.ts"],
      "extends": [
        "plugin:@typescript-eslint/recommended",
        "plugin:@typescript-eslint/recommended-requiring-type-checking"
      ],

      "parserOptions": {
        "project": ["./tsconfig.json"]
      }
    },
    {
      "files": ["*.test.ts"],
      "env": { "jest": true },
      "extends": ["plugin:jest/all"],
      "rules": {
        "jest/prefer-expect-assertions": ["error", { "onlyFunctionsWithAsyncKeyword": true }],
        "jest/require-hook": "off",
        "jest/no-hooks": "off"
      }
    }
  ],
  "settings": {
    "import/resolver": {
      "typescript": {}
    }
  }
}