Addon-a11y: Remove story-root reference

[shilman]

Originally posted by @kaelig in #16129 (comment)

By the way, what's this code supposed to do?

storybook/addons/a11y/src/a11yRunner.ts

Line 20 in 4750c6b

const storyRoot = document.getElementById('story-root');

Is #story-root a thing?

If this is only related to this addon, should it be documented?

[jam-awake]

I believe this was supposed to look up the element parameter value, if it is provided. I just specified the element parameter on Storybook 6.3.12 and I get "The scan encountered an error: {}" in the panel. When I dropped the element parameter, the addon works fine. So, I explored the source code to see the control flow:

1. axe is run on the element identifier
2. the element identifier refers to the element specified in input or the return of getElement if it isn't provided
3. getElement refers to an HTML element, either #root, the top-level div that contains a story by default when no decorators are used, or #story-root, a mysterious value.
4. input is the value returned by getParams
5. getParams either returns the element parameter if specified or null.

So, your real problem is that the element parameter's docs are incorrect. That parameter currently seems to do nothing.

[jsomsanith]

Hi 👋
Fixed proposed here: #17989
Thanks @jam-awake for the investigation

[jsomsanith]

PR merged

[shilman]

w00t!! I just released https://github.com/storybookjs/storybook/releases/tag/v6.5.0-beta.4 containing PR #17989 that references this issue. Upgrade today to the @next NPM tag to try it out!

npx sb upgrade --prerelease