.eslintrc.js

module.exports = {
  root: true,
  env: {
    node: true
  },
  extends: [
    'plugin:vue/essential',
    '@vue/airbnb'
  ],
  rules: {
    'comma-dangle': ['error', 'never'],
    // don't require .vue extension when importing
    'import/extensions': ['error', 'always', {
      js: 'never',
      vue: 'never'
    }],
    // disallow reassignment of function parameters
    // disallow parameter object manipulation except for specific exclusions
    'no-param-reassign': ['error', {
      props: true,
      ignorePropertyModificationsFor: [
        'state', // for vuex state
        'acc', // for reduce accumulators
        'e', // for e.returnvalue
        'cacheStorage' // used to cache data
      ]
    }],
    // allow optionalDependencies
    'import/no-extraneous-dependencies': ['error', {
      optionalDependencies: ['test/unit/index.js']
    }],
    'no-console': process.env.NODE_ENV === 'production' ? 'error' : 'off',
    'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off'
  },
  parserOptions: {
    parser: 'babel-eslint'
  }
};