Pass the CSS entrypoint to canonicalize as --css

[leoherbie]

tailwindcss canonicalize names its CSS entrypoint --css. It has done so since the subcommand was introduced (tailwindlabs/tailwindcss#19783) and has never accepted --input — it drops the flag silently and exits 0. CanonicalTailwind.Config.resolve_input/2 emits --input=<path> on both branches, so the entrypoint never reaches the CLI and every canonicalization runs against the stock @import "tailwindcss" design system instead of the project's — whether the path came from canonical_tailwind: [input: ...] or was discovered in a tailwind profile's args.

That is the same symptom v0.3.1 fixed for the split --input path form ("canonicalization ran without the project's @theme and plugins"): the path is now found, but it is still handed over under a flag the CLI ignores, so the theme stays out of reach through every path.

What it looks like

Our assets/css/app.css drops the default sm breakpoint and redefines sm as a max-width variant:

@theme { --breakpoint-sm: initial; }
@custom-variant sm (@media (width <= 40rem));

With that entrypoint, min-[40rem]: is a min-width query and sm: is a max-width one — not spellings of each other. mix format rewrote

<div class="min-[40rem]:flex p-4">

to class="p-4 sm:flex", inverting the breakpoint. Running the pinned CLI by hand:

$ printf 'min-[40rem]:flex p-4\n' | tailwindcss canonicalize --stream --input=assets/css/app.css
p-4 sm:flex
$ printf 'min-[40rem]:flex p-4\n' | tailwindcss canonicalize --stream --css=assets/css/app.css
p-4 min-[40rem]:flex

canonicalize --help on 4.3.3 lists --css, --format, --stream, -h and nothing else.

The change

resolve_input/2 and the two find_profile_input/1 head clauses emit --css= instead of --input=. The profile's entrypoint still arrives spelled --input, because that is the flag tailwindcss takes when building — only the flag handed to canonicalize changes. Since canonicalize has taken --css for its whole existence, this is safe across the supported range rather than version-dependent.

Why the suite did not catch it

test/fixtures/input.css and test/fixtures/other.css are both stock @import "tailwindcss", under which a dropped --input and an honoured --css produce byte-identical output — so the tests could only assert the argv, which was self-consistently wrong. This adds test/fixtures/themed.css with the @theme/@custom-variant above and a test that canonicalizes min-[40rem]:flex p-4 through it; collapsing to sm:flex now fails the suite. Green against both the supported floor (4.2.2) and the current CLI (4.3.3).

Happy to drop the CHANGELOG entry or reword it if you'd rather keep that yours.

[aptinio]

Thanks for catching this and adding the regression test, @leoherbie. Merged!