Split :has rules when using experimental.optimizeUniversalDefaults

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Ensure max specificity of `0,0,1` for button and input Preflight rules  ([#12735](https://github.com/tailwindlabs/tailwindcss/pull/12735))
 - Improve glob handling for folders with `(`, `)`, `[` or `]` in the file path ([#12715](https://github.com/tailwindlabs/tailwindcss/pull/12715))
+- Split `:has` rules when using `experimental.optimizeUniversalDefaults` ([#12736](https://github.com/tailwindlabs/tailwindcss/pull/12736))
 
 ### Added
 

src/lib/resolveDefaultsAtRules.js

@@ -104,8 +104,12 @@ export default function resolveDefaultsAtRules({ tailwindConfig }) {
             // we consider them separately because merging the declarations into
             // a single rule will cause browsers that do not understand the
             // vendor prefix to throw out the whole rule
+            // Additionally if a selector contains `:has` we also consider
+            // it separately because FF only recently gained support for it
             let selectorGroupName =
-              selector.includes(':-') || selector.includes('::-') ? selector : '__DEFAULT__'
+              selector.includes(':-') || selector.includes('::-') || selector.includes(':has')
+                ? selector
+                : '__DEFAULT__'
 
             let selectors = selectorGroups.get(selectorGroupName) ?? new Set()
             selectorGroups.set(selectorGroupName, selectors)

tests/resolve-defaults-at-rules.test.js

@@ -842,3 +842,58 @@ test('no defaults and apply without @tailwind base', () => {
     `)
   })
 })
+
+test('optimize universal defaults groups :has separately', () => {
+  let config = {
+    experimental: { optimizeUniversalDefaults: true },
+    content: [
+      { raw: html`<div class="ring-1"></div>` },
+      { raw: html`<div class="has-[:checked]:ring-1"></div>` },
+    ],
+    corePlugins: { preflight: false },
+  }
+
+  let input = css`
+    @tailwind base;
+    @tailwind utilities;
+  `
+
+  return run(input, config).then((result) => {
+    return expect(result.css).toMatchFormattedCss(css`
+      .ring-1 {
+        --tw-ring-inset: ;
+        --tw-ring-offset-width: 0px;
+        --tw-ring-offset-color: #fff;
+        --tw-ring-color: #3b82f680;
+        --tw-ring-offset-shadow: 0 0 #0000;
+        --tw-ring-shadow: 0 0 #0000;
+        --tw-shadow: 0 0 #0000;
+        --tw-shadow-colored: 0 0 #0000;
+      }
+      .has-\[\:checked\]\:ring-1:has(:checked) {
+        --tw-ring-inset: ;
+        --tw-ring-offset-width: 0px;
+        --tw-ring-offset-color: #fff;
+        --tw-ring-color: #3b82f680;
+        --tw-ring-offset-shadow: 0 0 #0000;
+        --tw-ring-shadow: 0 0 #0000;
+        --tw-shadow: 0 0 #0000;
+        --tw-shadow-colored: 0 0 #0000;
+      }
+      .ring-1 {
+        --tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width)
+          var(--tw-ring-offset-color);
+        --tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(1px + var(--tw-ring-offset-width))
+          var(--tw-ring-color);
+        box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow), var(--tw-shadow, 0 0 #0000);
+      }
+      .has-\[\:checked\]\:ring-1:has(:checked) {
+        --tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width)
+          var(--tw-ring-offset-color);
+        --tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(1px + var(--tw-ring-offset-width))
+          var(--tw-ring-color);
+        box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow), var(--tw-shadow, 0 0 #0000);
+      }
+    `)
+  })
+})