.eslintrc.js

const { resolve } = require('path');
module.exports = {
  // https://eslint.org/docs/user-guide/configuring#configuration-cascading-and-hierarchy
  // This option interrupts the configuration hierarchy at this file
  // Remove this if you have an higher level ESLint config file (it usually happens into a monorepos)
  root: true,

  // https://eslint.vuejs.org/user-guide/#how-to-use-custom-parser
  // Must use parserOptions instead of "parser" to allow vue-eslint-parser to keep working
  // `parser: 'vue-eslint-parser'` is already included with any 'plugin:vue/**' config and should be omitted
  parserOptions: {
    // https://github.com/typescript-eslint/typescript-eslint/tree/master/packages/parser#configuration
    // https://github.com/TypeStrong/fork-ts-checker-webpack-plugin#eslint
    // Needed to make the parser take into account 'vue' files
    extraFileExtensions: ['.vue'],
    parser: '@typescript-eslint/parser',
    project: resolve(__dirname, './tsconfig.json'),
    tsconfigRootDir: __dirname,
    ecmaVersion: 2018, // Allows for the parsing of modern ECMAScript features
    sourceType: 'module' // Allows for the use of imports
  },

  env: {
    browser: true
  },

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

    // https://github.com/typescript-eslint/typescript-eslint/tree/master/packages/eslint-plugin#usage
    // ESLint typescript rules
    'plugin:@typescript-eslint/recommended',
    // consider disabling this class of rules if linting takes too long
    'plugin:@typescript-eslint/recommended-requiring-type-checking',

    // Uncomment any of the lines below to choose desired strictness,
    // but leave only one uncommented!
    // See https://eslint.vuejs.org/rules/#available-rules
    'plugin:vue/essential', // Priority A: Essential (Error Prevention)
    // 'plugin:vue/strongly-recommended', // Priority B: Strongly Recommended (Improving Readability)
    // 'plugin:vue/recommended', // Priority C: Recommended (Minimizing Arbitrary Choices and Cognitive Overhead)

    // https://github.com/prettier/eslint-config-prettier#installation
    // usage with Prettier, provided by 'eslint-config-prettier'.
    'prettier'
  ],

  plugins: [
    // required to apply rules which need type information
    '@typescript-eslint',

    // https://eslint.vuejs.org/user-guide/#why-doesn-t-it-work-on-vue-file
    // required to lint *.vue files
    'vue',

    // https://github.com/typescript-eslint/typescript-eslint/issues/389#issuecomment-509292674
    // Prettier has not been included as plugin to avoid performance impact
    // add it as an extension for your IDE
  ],

  globals: {
    ga: 'readonly', // Google Analytics
    cordova: 'readonly',
    __statics: 'readonly',
    process: 'readonly',
    Capacitor: 'readonly',
    chrome: 'readonly'
  },

  // add your custom rules here
  rules: {
    'prefer-promise-reject-errors': 'off',

    // TypeScript
    quotes: ['warn', 'single', { avoidEscape: true }],
    '@typescript-eslint/explicit-function-return-type': 'off',
    '@typescript-eslint/explicit-module-boundary-types': 'off',

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