Add support for polyfill configuration in Vite plugin

[lubomirblazekcz]

As discussed in PR #19942, it would be great if the Vite plugin exposed an option to configure polyfills.

Currently, when optimize: false is set and the project targets browsers through Vite instead, there does not seem to be a way to disable Tailwind’s generated polyfills.

I’d like to propose adding a polyfills option alongside optimize in the Vite plugin configuration. This would allow users to either disable polyfills entirely during compilation, or selectively keep only the ones they need.

[wongjn]

Oops, didn't read the end comments in the linked PR - reopened your #20035 issue as #20038. Sorry!

[yudin-s]

I think the important design question is whether Tailwind's polyfills are part of the Tailwind output contract or part of the downstream browser-targeting pipeline.

If a project sets optimize: false because it wants Vite/Browserslist/Lightning CSS/etc. to own the target, then having Tailwind still emit mandatory compatibility transforms can be surprising. In that mode, a separate option makes sense:

tailwindcss({
  optimize: false,
  polyfills: false,
})

or a more future-proof shape:

tailwindcss({
  optimize: false,
  polyfills: {
    colorMix: false,
    logicalProperties: true,
  },
})

I would prefer a coarse false | true | object API over tying it only to optimize, because optimization and compatibility are related but not the same concern. Some teams may want unminified output with polyfills; others may want optimized output without certain polyfills because their own build target handles it.

The main risk is support burden: once this is configurable, bug reports need to include both browser target and Tailwind polyfill settings. But from a Vite plugin perspective, giving advanced users explicit ownership of compatibility transforms feels reasonable.