Create a lint rule for disabled controls

[TylerJDev]

Summary

We often have to deal with disabled controls in Primer which are typically inaccessible to most users. If we could create a rule that would help stem that usage, then it might reduce the amount of inaccessible patterns that are commonly used with the disabled attribute.

Idea

We cannot restrict usage of the disabled attribute outright, as it may be a good option in some cases. Since there are many different nuances for how and when this attribute is used, we should restrict this rule to only be applied in specific cases.

In forms

We provide guidance against disabling save/submit buttons in forms and instead provide a reason as to why the submission isn't successful. We could potentially create a rule that throws a violation against disabled submit buttons used within a <form>, or similar form-based components.

Example of bad usage:

<form>
  <label>Name
    <input type="text" name="name" required />
  </label>

  <label>
    Bio
    <textarea name="bio" rows="5" />
  </label>
  
  <!-- The control is disabled, but provides no explanation as to why -->
  <button type="submit" disabled>Save</button>
</form>

We could warn in instances where disabled is used for the submit control, much like in the example above.

As suggestions

ESLint allows you to provide suggestions to patterns without throwing an error. We could utilize this to steer developers away from disabled, by encouraging them to look into using a more accessible pattern that will fits their needs.

[lesliecdubs]

@TylerJDev 👋🏻 I added this to the a11y eng Inbox for us to triage and prioritize, but if you were thinking this would be better addressed through avenue let me know!

[TylerJDev]

Yup, that's perfect @lesliecdubs! Thank you!