vue/require-explicit-emits - emits [] inside mixin is not being recognised by eslint

[nicholaszuccarelli]

Checklist

• I have tried restarting my IDE and the issue persists.
• I have read the FAQ and my problem is not listed.

Tell us about your environment

• ESLint version: 8.32.0
• eslint-plugin-vue version: 9.9.0
• Node version: 16.18.1
• Operating System: Windows 11 22621

Please show your full configuration:

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,

  parserOptions: {
    parser: '@babel/eslint-parser',
    ecmaVersion: 2018, // Allows for the parsing of modern ECMAScript features
    sourceType: 'module' // Allows for the use of imports
  },

  env: {
    browser: true,
    'vue/setup-compiler-macros': true
  },

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

    // 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/vue3-recommended', // Priority A: Essential (Error Prevention)
    // 'plugin:vue/vue3-strongly-recommended', // Priority B: Strongly Recommended (Improving Readability)
    // 'plugin:vue/vue3-recommended', // Priority C: Recommended (Minimizing Arbitrary Choices and Cognitive Overhead)

    'standard'

  ],

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

  ],

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

  // add your custom rules here
  rules: {

    // allow async-await
    'generator-star-spacing': 'off',
    // allow paren-less arrow functions
    'arrow-parens': 'off',
    'one-var': 'off',
    'no-void': 'off',
    'multiline-ternary': 'off',

    'import/first': 'off',
    'import/named': 'error',
    'import/namespace': 'error',
    'import/default': 'error',
    'import/export': 'error',
    'import/extensions': 'off',
    'import/no-unresolved': 'off',
    'import/no-extraneous-dependencies': 'off',

    'prefer-promise-reject-errors': 'off',

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

What did you do?

Sample Project containing the Vue3 ESLint error: https://github.com/nicholaszuccarelli/quasar-broken-popover-inside-field
Essentially, I've created a component and used a mixin on the component (using options API).
The mixin contains the emits[] array of some properties that the component can emit.

The component example:
<template>
  <div>
    <q-btn @click="$emit('sample')" />
  </div>
</template>

<script>
import sampleMixin from './sampleMixin'

export default defineComponent({
  name: 'IndexPage',
  mixins: [sampleMixin]
})
</script>

The mixin:
export default {
  emits: ['sample']
}

What did you expect to happen?
ESLint should recognise that the mixin contains a 'sample' emitter property (should not show warning).
While this is a simple use-case, I have 10+ components which inherit a single mixin which emits an event - it becomes troublesome having to define these same emits[] arrays in each of the components which share the single mixin.

What actually happened?

55:18 warning The "sample" event has been triggered but not declared on emits option vue/require-explicit-emits

✖ 1 problem (0 errors, 1 warning)

Repository to reproduce this issue

https://github.com/nicholaszuccarelli/quasar-broken-popover-inside-field

(npm install then quasar dev to run project)

[vedmant]

I have the same issue, I have needed emits in a mixin, but eslint is still requiring to add emits to a component that imports that mixin.

[FloEdelmann]

ESLint has no access to files other than the currently linted one. So we can either exclude components containing a mixin completely from this check (and similar ones), or require users to rewrite their code, or require users to disable the rule.

[nicholaszuccarelli]

Could you make it a setting to exclude components which contain a mixin? I think this would be most appropriate.

[FloEdelmann]

A pull request adding a boolean ignoreMixins option (default false) would be accepted.