• ESLint Version: 7.23.0
• Node Version: 15.4.0
• npm Version: 7.1.1
• Operating System: linux 5.4.0-70-generic
• Parser: @babel/eslint-parser

module.exports = {
  root: true,
  parserOptions: {
    parser: '@babel/eslint-parser',
    ecmaVersion: 2018,
    sourceType: 'module'
  },
  extends: [
    'standard',
    'plugin:vue/recommended'
  ],
  plugins: ['vue'],
  rules: {
    'max-len': ['warn', { code: 120 }],
    'vue/no-v-html': 'off'
  }
}

ESLint CLI usage:

eslint --cache --ext .js,.vue --max-warnings 0

What did you expect to happen?

I expected to have and error in console: 'patterns' must be a non-empty string or an array of non-empty strings.

Instead, I got no response at all (and no actual linting performed, of course).

$ eslint --cache --ext .js,.vue --max-warnings 0
Done in 0.23s.

How to replicate?

1. Run eslint CLI with no positional parameters.
2. No error is shown .

More details

The condition in ESLint engine code is accepting an empty list as a valid list of non empty strings. It boils down to the fact that a call to .every(...) method of an empty list is always true (see isArrayOfNonEmptyString function)

I'm more than OK to prepare a PR to fix this.

Thanks!