.eslintrc.js

module.exports = {
  root: true,

  parserOptions: {
    parser: '@typescript-eslint/parser',
    project: './tsconfig.json',
    sourceType: 'module',
  },

  env: {
    node: true,
  },

  // Rules order is important, please avoid shuffling them
  extends: [
    // Base ESLint recommended rules
    'eslint:recommended',

    // ESLint typescript rules
    // See https://github.com/typescript-eslint/typescript-eslint/tree/master/packages/eslint-plugin#usage
    'plugin:@typescript-eslint/recommended',
    'plugin:@typescript-eslint/recommended-requiring-type-checking',

    // Usage with Prettier, provided by 'eslint-config-prettier'.
    // https://github.com/typescript-eslint/typescript-eslint/tree/master/packages/eslint-plugin#usage-with-prettier
    'prettier',
  ],

  plugins: [
    // Required to apply rules which need type information
    '@typescript-eslint',
    // Prettier has not been included as plugin to avoid performance impact
    // See https://github.com/typescript-eslint/typescript-eslint/issues/389#issuecomment-509292674
    // Add it as an extension for your IDE
  ],

  // add your custom rules here
  rules: {
    'prefer-promise-reject-errors': 'off',
    quotes: ['warn', 'single'],

    // allow console.log during development only
    'no-console': process.env.NODE_ENV === 'production' ? 'error' : 'off',
    // allow debugger during development only
    'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off',
  },
};