.eslintrc.js

// https://eslint.org/docs/user-guide/configuring
// File taken from https://github.com/vuejs-templates/webpack/blob/1.3.1/template/.eslintrc.js, thanks.

module.exports = {
  root: true,
  parserOptions: {
    parser: 'babel-eslint'
  },
  env: {
    browser: true,
    webextensions: true,
  },
  // https://github.com/vuejs/eslint-plugin-vue#priority-a-essential-error-prevention
  // consider switching to `plugin:vue/strongly-recommended` or `plugin:vue/recommended` for stricter rules.
  extends: [
    'plugin:vue-i18n/recommended',
    'plugin:vue/essential',
    'airbnb-base',
    'plugin:prettier/recommended'
  ],
  // required to lint *.vue files
  plugins: [
    'vue'
  ],
  // check if imports actually resolve
  settings: {
    'import/resolver': {
      webpack: {
        config: './webpack.config.js'
      }
    },
    'vue-i18n': {
      localeDir: './src/locales/*.json',
    },
  },
  // add your custom rules here
  rules: {
    // 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
      ]
    }],
    // allow debugger during development
    'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off',
    'vue-i18n/no-dynamic-keys': 'error',
    'vue-i18n/no-unused-keys': 'error',
    'vue-i18n/no-raw-text': 'error',
  }
}