Draft: Tailwind config generation POC

What does this MR do?

POC implementation based on #2158 (comment 1420340750)

If we are able to generate a tailwind.config.js file with our existing utility classes then we can take advantage of the Tailwind CSS VSCode extension autocomplete. It also gets us closer to using Tailwind because we will have a list of supported classes and a list of unsupported classes.

We should be able to leverage the preset option to use this generated tailwind.config.js file in the gitlab-org/gitlab project.

This MR adds a script that does the following:

1. Generates all the possible Tailwind utility classes
2. Creates a tailwind.config.js file
3. Parses the GitLab UI utility classes and compares them against the Tailwind utility classes. The utility classes that are supported by Tailwind are added to the safelist in the tailwind.config.js file. The utility classes that are not supported are added via the addUtilities plugin function.

Local testing

1. Check out this branch
2. Run yarn install
3. Run yarn build to generate GitLab UI utility classes
4. Run npx tailwindcss -i ./tailwind/tailwind.css -o ./dist/tailwind.css --config ./tailwind/generate-tailwind.config.js to generate Tailwind utility classes
5. Run node ./tailwind/compare.js to generate tailwind.config.js
6. Install the Tailwind CSS VSCode extension
7. Go to any component, create a div and add a class attribute.
   • If the autocomplete isn't popping up you may need to do control + space. I think this has to do with a VSCode setting but haven't dug into it yet.

Pros and cons

Pros

1. Allows us to use the Tailwind CSS VSCode extension for autocomplete
2. Generates a list of utility classes that are supported or not supported by Tailwind
3. Get started on setting up the config so we could potentially generate the utility classes with Tailwind

Cons

1. Added time/complexity to the GitLab UI build task. Building all the Tailwind utility classes can take over a minute.

Screenshots or screen recordings

Utility class supported by Tailwind (added to safelist)

Utility class not supported by Tailwind (added via the addUtilities plugin function)

Color utility classes

Nice to have the color preview 🙂

Integration merge requests

• GitLab: mr_url
• CustomersDot: mr_url
• Status Page: mr_url

Does this MR meet the acceptance criteria?

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Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

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Accessibility

If this MR adds or modifies a component, take a few moments to review the following:

• All actions and functionality can be done with a keyboard.
• Links, buttons, and controls have a visible focus state.
• All content is presented in text or with a text equivalent. For example, alt text for SVG, or aria-label for icons that have meaning or perform actions.
• Changes in a component’s state are announced by a screen reader. For example, changing aria-expanded="false" to aria-expanded="true" when an accordion is expanded.
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