Upgrade codemod (v4.0.6) does not cover deprecated utilities for opacity

[alexmkio]

What version of Tailwind CSS are you using?

For example: v3.4.1

What build tool (or framework if it abstracts the build tool) are you using?

For example: Next.js 15.1.7

What version of Node.js are you using?

For example: v22.14.0

What browser are you using?

For example: Chrome

What operating system are you using?

For example: macOS

Reproduction URL
alexmkio/v3-tailwind@c498823#diff-73d7a23e5015801b9bcc9db601d6ec9594d3eb34e5bb23154e0ae4b0c30f1a3bR6
See line 6 of /src/app/page.tsx

Describe your issue

Using the latest upgrade codemod (v4.0.6) when upgrading from version 3 (3.4.1) to version 4 the utilities for bg-opacity-, text-opacity-, border-opacity-, divide-opacity-, ring-opacity-, placeholder-opacity- are not updated or ported to their v4 counterparts. For example, I'd expect that if I have a string of classes which contains "bg-indigo-600 bg-opacity-75" that it would become "bg-indigo-600/75".

[philipp-spiess]

@alexmkio Yeah this is unfortunately a limitation of the current setup of the migration tool. The reason for this is that the tool currently operates on individual class names only and doesn't understand connections between them when they are applied to the same element I reckon.

We have some ideas how to improve this but I can't promise you when we will get to it. I definitely recommend manually reviewing the changes by the codemod though.

I've moved this into the idea section since it's not something we'll have time to investigate and improve immediately I'm afraid, however we'd love to get to it!

[alexmkio]

@philipp-spiess That all makes sense, and I wonder if in the meantime it would be helpful to explicitly mention the breaking changes that are not covered by the codemod in the documentation. Those changes being: bg-opacity-, text-opacity-, border-opacity-, divide-opacity-, ring-opacity-, placeholder-opacity-, corePlugins (there being no coverage for this in v4), and resolveConfig (there being several options for this in v4, but with the codemod not covering it results in broken builds).