.eslintrc.json

{
  "root": true,
  "env": {
    "node": true,
    "es6": true,
    "es2016": true
  },
  "extends": [
    "eslint:recommended"
  ],
  "parserOptions": {
    "ecmaVersion": 13,
    "sourceType": "module"
  },
  "rules": {
    "strict": [
      "error",
      "global"
    ],
    "no-duplicate-imports": [
      "error",
      {
        "includeExports": true
      }
    ],
    "no-promise-executor-return": "error",
    "require-atomic-updates": "error",
    "no-use-before-define": [
      "error",
      {
        "functions": false
      }
    ],
    "no-constant-binary-expression": "error",
    "block-scoped-var": "error",
    "no-return-await": "error",
    "require-await": "error",
    "func-names": "off",
    "curly": [
      "error",
      "multi-or-nest"
    ],
    "eqeqeq": "error",
    "id-length": [
      "error",
      {
        "exceptions": [
          "i"
        ]
      }
    ],
    "arrow-spacing": "error",
    "arrow-parens": [
      "error",
      "as-needed"
    ],
    "array-bracket-newline": "error",
    "array-element-newline": [
      "error",
      "consistent"
    ],
    "no-multi-spaces": "error",
    "no-trailing-spaces": "error",
    "no-whitespace-before-property": "error",
    "object-curly-spacing": [
      "error",
      "always"
    ],
    "object-curly-newline": [
      "error",
      {
        "consistent": true
      }
    ],
    "object-property-newline": "error",
    "semi": [
      "error",
      "always"
    ],
    "semi-spacing": [
      "error",
      {
        "before": false,
        "after": true
      }
    ],
    "semi-style": [
      "error",
      "last"
    ],
    "quotes": [
      "error",
      "double"
    ],
    "no-unused-vars": "off"
  },
  "overrides": [
    {
      "files": [
        "**/*.ts"
      ],
      "env": {
        "browser": true,
        "es6": true,
        "es2016": true
      },
      "extends": [
        "eslint:recommended",
        "plugin:@typescript-eslint/strict"
      ],
      "parser": "@typescript-eslint/parser",
      "parserOptions": {
        "project": [
          "./tsconfig.json",
          "./tests/tsconfig.json"
        ]
      },
      "plugins": [
        "@typescript-eslint"
      ],
      "rules": {
        "no-console": "error",
        "@typescript-eslint/array-type": [
          "error",
          {
            "default": "array",
            "readonly": "array"
          }
        ],
        "@typescript-eslint/consistent-generic-constructors": [
          "error",
          "type-annotation"
        ],
        "@typescript-eslint/explicit-function-return-type": "error",
        "@typescript-eslint/consistent-type-exports": "error",
        "@typescript-eslint/consistent-type-imports": "error",
        "@typescript-eslint/consistent-type-definitions": "off",
        "@typescript-eslint/no-unnecessary-condition": "off",
        "@typescript-eslint/no-unused-vars": "error",
        "@typescript-eslint/prefer-nullish-coalescing": "off"
      }
    }
  ]
}