Collapse more utilities by expanding their declarations

CHANGELOG.md

@@ -16,7 +16,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Improve canonicalizations for `tracking-*` utilities ([#19827](https://github.com/tailwindlabs/tailwindcss/pull/19827))
 - Fix crash due to invalid characters in candidate ([#19829](https://github.com/tailwindlabs/tailwindcss/pull/19829))
 - Ensure query params in imports are considered unique resources when using `@tailwindcss/webpack` ([#19723](https://github.com/tailwindlabs/tailwindcss/pull/19723))
-- Collapse arbitrary values into shorthand utilities during canonicalization ([#19837](https://github.com/tailwindlabs/tailwindcss/pull/19837))
+- Canonicalization: collapse arbitrary values into shorthand utilities (e.g. `px-[1.2rem] py-[1.2rem]` → `p-[1.2rem]`) ([#19837](https://github.com/tailwindlabs/tailwindcss/pull/19837))
+- Canonicalization: collapse `border-{t,b}-*` into `border-y-*`, `border-{l,r}-*` into `border-x-*`, and `border-{t,r,b,l}-*` into `border-*` ([#19842](https://github.com/tailwindlabs/tailwindcss/pull/19842))
+- Canonicalization: collapse `scroll-m{t,b}-*` into `scroll-my-*`, `scroll-m{l,r}-*` into `scroll-mx-*`, and `scroll-m{t,r,b,l}-*` into `scroll-m-*` ([#19842](https://github.com/tailwindlabs/tailwindcss/pull/19842))
+- Canonicalization: collapse `scroll-p{t,b}-*` into `scroll-py-*`, `scroll-p{l,r}-*` into `scroll-px-*`, and `scroll-p{t,r,b,l}-*` into `scroll-p-*` ([#19842](https://github.com/tailwindlabs/tailwindcss/pull/19842))
+- Canonicalization: collapse `overflow-{x,y}-*` into `overflow-*` ([#19842](https://github.com/tailwindlabs/tailwindcss/pull/19842))
+- Canonicalization: collapse `overscroll-{x,y}-*` into `overscroll-*` ([#19842](https://github.com/tailwindlabs/tailwindcss/pull/19842))
 
 ## [4.2.2] - 2026-03-18
 

packages/tailwindcss/src/canonicalize-candidates.test.ts

@@ -1044,9 +1044,21 @@ describe.each([['default'], ['with-variant'], ['important'], ['prefix']])('%s',
     test.each([
       // 4 to 1
       ['mt-1 mr-1 mb-1 ml-1', 'm-1'],
+      ['border-t-123 border-r-123 border-b-123 border-l-123', 'border-123'],
+      ['border-t-1 border-r-1 border-b-1 border-l-1', 'border'], // `border` is shorter than `border-1`
+      ['border-t-red-500 border-r-red-500 border-b-red-500 border-l-red-500', 'border-red-500'],
+      ['scroll-mt-1 scroll-mr-1 scroll-mb-1 scroll-ml-1', 'scroll-m-1'],
+      ['scroll-pt-1 scroll-pr-1 scroll-pb-1 scroll-pl-1', 'scroll-p-1'],
 
       // 2 to 1
       ['mt-1 mb-1', 'my-1'],
+      ['border-t-123 border-b-123', 'border-y-123'],
+      ['border-t-1 border-b-1', 'border-y'], // `border-y` is shorter than `border-y-1`
+      ['border-t-red-500 border-b-red-500', 'border-y-red-500'],
+      ['scroll-mt-1 scroll-mb-1', 'scroll-my-1'],
+      ['scroll-pt-1 scroll-pb-1', 'scroll-py-1'],
+      ['overflow-x-hidden overflow-y-hidden', 'overflow-hidden'],
+      ['overscroll-x-contain overscroll-y-contain', 'overscroll-contain'],
 
       // Different order as above
       ['mb-1 mt-1', 'my-1'],