Parse alpha value from rgba/hsla colors when using variables

CHANGELOG.md

@@ -43,6 +43,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Ensure generated CSS is always sorted in the same order for a given set of templates ([#10382](https://github.com/tailwindlabs/tailwindcss/pull/10382))
 - Handle variants when the same class appears multiple times in a selector ([#10397](https://github.com/tailwindlabs/tailwindcss/pull/10397))
 - Handle group/peer variants with quoted strings ([#10400](https://github.com/tailwindlabs/tailwindcss/pull/10400))
+- Parse alpha value from rgba/hsla colors when using variables ([#10429](https://github.com/tailwindlabs/tailwindcss/pull/10429))
 
 ### Changed
 

src/util/color.js

@@ -8,10 +8,10 @@ let ALPHA_SEP = /\s*[,/]\s*/
 let CUSTOM_PROPERTY = /var\(--(?:[^ )]*?)\)/
 
 let RGB = new RegExp(
-  `^(rgb)a?\\(\\s*(${VALUE.source}|${CUSTOM_PROPERTY.source})(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${ALPHA_SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?\\s*\\)$`
+  `^(rgba?)\\(\\s*(${VALUE.source}|${CUSTOM_PROPERTY.source})(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${ALPHA_SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?\\s*\\)$`
 )
 let HSL = new RegExp(
-  `^(hsl)a?\\(\\s*((?:${VALUE.source})(?:deg|rad|grad|turn)?|${CUSTOM_PROPERTY.source})(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${ALPHA_SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?\\s*\\)$`
+  `^(hsla?)\\(\\s*((?:${VALUE.source})(?:deg|rad|grad|turn)?|${CUSTOM_PROPERTY.source})(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?(?:${ALPHA_SEP.source}(${VALUE.source}|${CUSTOM_PROPERTY.source}))?\\s*\\)$`
 )
 
 // In "loose" mode the color may contain fewer than 3 parts, as long as at least
@@ -52,6 +52,16 @@ export function parseColor(value, { loose = false } = {}) {
 
   let color = [match[2], match[3], match[4]].filter(Boolean).map((v) => v.toString())
 
+  // rgba(var(--my-color), 0.1)
+  // hsla(var(--my-color), 0.1)
+  if (color.length === 2 && color[0].startsWith('var(')) {
+    return {
+      mode: match[1],
+      color: [color[0]],
+      alpha: color[1],
+    }
+  }
+
   if (!loose && color.length !== 3) {
     return null
   }
@@ -69,5 +79,10 @@ export function parseColor(value, { loose = false } = {}) {
 
 export function formatColor({ mode, color, alpha }) {
   let hasAlpha = alpha !== undefined
+
+  if (mode === 'rgba' || mode === 'hsla') {
+    return `${mode}(${color.join(', ')}${hasAlpha ? `, ${alpha}` : ''})`
+  }
+
   return `${mode}(${color.join(' ')}${hasAlpha ? ` / ${alpha}` : ''})`
 }

tests/color.test.js

@@ -11,7 +11,7 @@ crosscheck(() => {
       ${'#0088cc99'}                               | ${{ mode: 'rgb', color: ['0', '136', '204'], alpha: '0.6' }}
       ${'#08c9'}                                   | ${{ mode: 'rgb', color: ['0', '136', '204'], alpha: '0.6' }}
       ${'rgb(0, 30, 60)'}                          | ${{ mode: 'rgb', color: ['0', '30', '60'], alpha: undefined }}
-      ${'rgba(0, 30, 60, 0.5)'}                    | ${{ mode: 'rgb', color: ['0', '30', '60'], alpha: '0.5' }}
+      ${'rgba(0, 30, 60, 0.5)'}                    | ${{ mode: 'rgba', color: ['0', '30', '60'], alpha: '0.5' }}
       ${'rgb(0 30 60)'}                            | ${{ mode: 'rgb', color: ['0', '30', '60'], alpha: undefined }}
       ${'rgb(0 30 60 / 0.5)'}                      | ${{ mode: 'rgb', color: ['0', '30', '60'], alpha: '0.5' }}
       ${'rgb(var(--foo), 30, 60)'}                 | ${{ mode: 'rgb', color: ['var(--foo)', '30', '60'], alpha: undefined }}
@@ -31,11 +31,11 @@ crosscheck(() => {
       ${'hsl(0rad, 30%, 60%)'}                     | ${{ mode: 'hsl', color: ['0rad', '30%', '60%'], alpha: undefined }}
       ${'hsl(0grad, 30%, 60%)'}                    | ${{ mode: 'hsl', color: ['0grad', '30%', '60%'], alpha: undefined }}
       ${'hsl(0turn, 30%, 60%)'}                    | ${{ mode: 'hsl', color: ['0turn', '30%', '60%'], alpha: undefined }}
-      ${'hsla(0, 30%, 60%, 0.5)'}                  | ${{ mode: 'hsl', color: ['0', '30%', '60%'], alpha: '0.5' }}
-      ${'hsla(0deg, 30%, 60%, 0.5)'}               | ${{ mode: 'hsl', color: ['0deg', '30%', '60%'], alpha: '0.5' }}
-      ${'hsla(0rad, 30%, 60%, 0.5)'}               | ${{ mode: 'hsl', color: ['0rad', '30%', '60%'], alpha: '0.5' }}
-      ${'hsla(0grad, 30%, 60%, 0.5)'}              | ${{ mode: 'hsl', color: ['0grad', '30%', '60%'], alpha: '0.5' }}
-      ${'hsla(0turn, 30%, 60%, 0.5)'}              | ${{ mode: 'hsl', color: ['0turn', '30%', '60%'], alpha: '0.5' }}
+      ${'hsla(0, 30%, 60%, 0.5)'}                  | ${{ mode: 'hsla', color: ['0', '30%', '60%'], alpha: '0.5' }}
+      ${'hsla(0deg, 30%, 60%, 0.5)'}               | ${{ mode: 'hsla', color: ['0deg', '30%', '60%'], alpha: '0.5' }}
+      ${'hsla(0rad, 30%, 60%, 0.5)'}               | ${{ mode: 'hsla', color: ['0rad', '30%', '60%'], alpha: '0.5' }}
+      ${'hsla(0grad, 30%, 60%, 0.5)'}              | ${{ mode: 'hsla', color: ['0grad', '30%', '60%'], alpha: '0.5' }}
+      ${'hsla(0turn, 30%, 60%, 0.5)'}              | ${{ mode: 'hsla', color: ['0turn', '30%', '60%'], alpha: '0.5' }}
       ${'hsl(0 30% 60%)'}                          | ${{ mode: 'hsl', color: ['0', '30%', '60%'], alpha: undefined }}
       ${'hsl(0deg 30% 60%)'}                       | ${{ mode: 'hsl', color: ['0deg', '30%', '60%'], alpha: undefined }}
       ${'hsl(0rad 30% 60%)'}                       | ${{ mode: 'hsl', color: ['0rad', '30%', '60%'], alpha: undefined }}
@@ -58,6 +58,10 @@ crosscheck(() => {
       ${'hsl(0 30% var(--foo) / 0.5)'}             | ${{ mode: 'hsl', color: ['0', '30%', 'var(--foo)'], alpha: '0.5' }}
       ${'hsl(var(--foo) 30% var(--bar))'}          | ${{ mode: 'hsl', color: ['var(--foo)', '30%', 'var(--bar)'], alpha: undefined }}
       ${'hsl(var(--foo) var(--bar) var(--baz))'}   | ${{ mode: 'hsl', color: ['var(--foo)', 'var(--bar)', 'var(--baz)'], alpha: undefined }}
+      ${'rgba(var(--foo), 0.1)'}                   | ${{ mode: 'rgba', color: ['var(--foo)'], alpha: '0.1' }}
+      ${'rgba(var(--foo), var(--alpha))'}          | ${{ mode: 'rgba', color: ['var(--foo)'], alpha: 'var(--alpha)' }}
+      ${'hsla(var(--foo), 0.1)'}                   | ${{ mode: 'hsla', color: ['var(--foo)'], alpha: '0.1' }}
+      ${'hsla(var(--foo), var(--alpha))'}          | ${{ mode: 'hsla', color: ['var(--foo)'], alpha: 'var(--alpha)' }}
       ${'transparent'}                             | ${{ mode: 'rgb', color: ['0', '0', '0'], alpha: '0' }}
     `('should parse "$color" to the correct value', ({ color, output }) => {
       expect(parseColor(color)).toEqual(output)

tests/opacity.test.js

@@ -1031,4 +1031,27 @@ crosscheck(() => {
       `)
     })
   })
+
+  it('can replace the potential alpha value in rgba/hsla syntax', async () => {
+    let config = {
+      content: [{ raw: html` <div class="text-primary-rgba/50 text-primary-hsla/50"></div> ` }],
+      theme: {
+        colors: {
+          'primary-rgba': 'rgba(var(--color), 0.1)',
+          'primary-hsla': 'hsla(var(--color), 0.1)',
+        },
+      },
+    }
+
+    let result = await run('@tailwind utilities', config)
+
+    expect(result.css).toMatchCss(css`
+      .text-primary-hsla\/50 {
+        color: hsla(var(--color), 0.5);
+      }
+      .text-primary-rgba\/50 {
+        color: rgba(var(--color), 0.5);
+      }
+    `)
+  })
 })