title: How to read EsLint rule syntax?
body: <p>I'm trying to learn more about eslint. In the description for a rule I found <a href="https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/function-component-definition.md#rule-options" rel="nofollow noreferrer">this explanation</a>:</p>
  <pre><code>&quot;react/function-component-definition&quot;: [&lt;enabled&gt;, {
    &quot;namedComponents&quot;: &quot;function-declaration&quot; | &quot;function-expression&quot; | &quot;arrow-function&quot; | Array&lt;&quot;function-declaration&quot; | &quot;function-expression&quot; | &quot;arrow-function&quot;&gt;,
    &quot;unnamedComponents&quot;: &quot;function-expression&quot; | &quot;arrow-function&quot; | Array&lt;&quot;function-expression&quot; | &quot;arrow-function&quot;&gt;
  }]
  </code></pre>
  <p>However, I'm a bit confused by this. Some google'ing made me realize that  can be used to see the warning-error level. Other than that I figured out that plain values are also accepted:</p>
  <pre><code>'react/function-component-definition': [
      2,
      {
          namedComponents: 'function-declaration',
      },
   ],
  </code></pre>
  <p>The explanation also suggests that <code>namedComponents</code> can take an array but when I try to pass in values in brackets e. g. <code>['function-declaration', '...']</code> I get an error. I'd love to know if and how I can pass an Array to this file?</p>
  <p>I'd also love to know how I can learn more about the syntax of the explanation above if that is a standardized notation.</p>