JIT: Add exhaustive pseudo-class and pseudo-element variant support (#4482)

* Add first-line, first-letter, and marker variants

* Add selection variant

Co-Authored-By: Eric Rodrigues Pires <[email protected]>

* Add remaining pseudo-class variants

* Add target pseudo-class

Co-Authored-By: Peter Neupauer <[email protected]>

* add test for parallel variants

* implement parallel variants

Co-authored-by: Eric Rodrigues Pires <[email protected]>
Co-authored-by: Peter Neupauer <[email protected]>
Co-authored-by: Robin Malfait <[email protected]>

Author: 4 people

src/jit/corePlugins.js

@@ -11,7 +11,55 @@ import {
 } from '../util/pluginUtils'
 
 export default {
-  pseudoClassVariants: function ({ config, addVariant }) {
+  pseudoElementVariants: function ({ config, addVariant }) {
+    addVariant(
+      'first-letter',
+      transformAllSelectors((selector) => {
+        return updateAllClasses(selector, (className, { withPseudo }) => {
+          return withPseudo(`first-letter${config('separator')}${className}`, '::first-letter')
+        })
+      })
+    )
+
+    addVariant(
+      'first-line',
+      transformAllSelectors((selector) => {
+        return updateAllClasses(selector, (className, { withPseudo }) => {
+          return withPseudo(`first-line${config('separator')}${className}`, '::first-line')
+        })
+      })
+    )
+
+    addVariant('marker', [
+      transformAllSelectors((selector) => {
+        let variantSelector = updateAllClasses(selector, (className) => {
+          return `marker${config('separator')}${className}`
+        })
+
+        return `${variantSelector} *::marker`
+      }),
+      transformAllSelectors((selector) => {
+        return updateAllClasses(selector, (className, { withPseudo }) => {
+          return withPseudo(`marker${config('separator')}${className}`, '::marker')
+        })
+      }),
+    ])
+
+    addVariant('selection', [
+      transformAllSelectors((selector) => {
+        let variantSelector = updateAllClasses(selector, (className) => {
+          return `selection${config('separator')}${className}`
+        })
+
+        return `${variantSelector} *::selection`
+      }),
+      transformAllSelectors((selector) => {
+        return updateAllClasses(selector, (className, { withPseudo }) => {
+          return withPseudo(`selection${config('separator')}${className}`, '::selection')
+        })
+      }),
+    ])
+
     addVariant(
       'before',
       transformAllSelectors(
@@ -55,16 +103,40 @@ export default {
         }
       )
     )
-
+  },
+  pseudoClassVariants: function ({ config, addVariant }) {
     let pseudoVariants = [
+      // Positional
       ['first', 'first-child'],
       ['last', 'last-child'],
+      ['only', 'only-child'],
       ['odd', 'nth-child(odd)'],
       ['even', 'nth-child(even)'],
+      'first-of-type',
+      'last-of-type',
+      'only-of-type',
+
+      // State
       'visited',
+      'target',
+
+      // Forms
+      'default',
       'checked',
-      'empty',
+      'indeterminate',
+      'placeholder-shown',
+      'autofill',
+      'required',
+      'valid',
+      'invalid',
+      'in-range',
+      'out-of-range',
       'read-only',
+
+      // Content
+      'empty',
+
+      // Interactive
       'focus-within',
       'hover',
       'focus',

src/jit/lib/generateRules.js

@@ -100,7 +100,7 @@ function applyVariant(variant, matches, context) {
   }
 
   if (context.variantMap.has(variant)) {
-    let [variantSort, applyThisVariant] = context.variantMap.get(variant)
+    let variantFunctionTuples = context.variantMap.get(variant)
     let result = []
 
     for (let [{ sort, layer, options }, rule] of matches) {
@@ -112,36 +112,39 @@ function applyVariant(variant, matches, context) {
       let container = postcss.root()
       container.append(rule.clone())
 
-      function modifySelectors(modifierFunction) {
-        container.each((rule) => {
-          if (rule.type !== 'rule') {
-            return
-          }
-
-          rule.selectors = rule.selectors.map((selector) => {
-            return modifierFunction({
-              get className() {
-                return getClassNameFromSelector(selector)
-              },
-              selector,
+      for (let [variantSort, variantFunction] of variantFunctionTuples) {
+        let clone = container.clone()
+        function modifySelectors(modifierFunction) {
+          clone.each((rule) => {
+            if (rule.type !== 'rule') {
+              return
+            }
+
+            rule.selectors = rule.selectors.map((selector) => {
+              return modifierFunction({
+                get className() {
+                  return getClassNameFromSelector(selector)
+                },
+                selector,
+              })
             })
           })
+          return clone
+        }
+
+        let ruleWithVariant = variantFunction({
+          container: clone,
+          separator: context.tailwindConfig.separator,
+          modifySelectors,
         })
-        return container
-      }
 
-      let ruleWithVariant = applyThisVariant({
-        container,
-        separator: context.tailwindConfig.separator,
-        modifySelectors,
-      })
+        if (ruleWithVariant === null) {
+          continue
+        }
 
-      if (ruleWithVariant === null) {
-        continue
+        let withOffset = [{ sort: variantSort | sort, layer, options }, clone.nodes[0]]
+        result.push(withOffset)
       }
-
-      let withOffset = [{ sort: variantSort | sort, layer, options }, container.nodes[0]]
-      result.push(withOffset)
     }
 
     return result

src/jit/lib/setupContextUtils.js

@@ -13,6 +13,7 @@ import isPlainObject from '../../util/isPlainObject'
 import escapeClassName from '../../util/escapeClassName'
 import nameClass from '../../util/nameClass'
 import { coerceValue } from '../../util/pluginUtils'
+import bigSign from '../../util/bigSign'
 import corePlugins from '../corePlugins'
 import * as sharedState from './sharedState'
 import { env } from './sharedState'
@@ -152,9 +153,11 @@ function buildPluginApi(tailwindConfig, context, { variantList, variantMap, offs
   }
 
   return {
-    addVariant(variantName, applyThisVariant, options = {}) {
+    addVariant(variantName, variantFunctions, options = {}) {
+      variantFunctions = [].concat(variantFunctions)
+
       insertInto(variantList, variantName, options)
-      variantMap.set(variantName, applyThisVariant)
+      variantMap.set(variantName, variantFunctions)
     },
     postcss,
     prefix: applyConfiguredPrefix,
@@ -395,7 +398,7 @@ function resolvePlugins(context, tailwindDirectives, root) {
 
   // TODO: This is a workaround for backwards compatibility, since custom variants
   // were historically sorted before screen/stackable variants.
-  let beforeVariants = [corePlugins['pseudoClassVariants']]
+  let beforeVariants = [corePlugins['pseudoElementVariants'], corePlugins['pseudoClassVariants']]
   let afterVariants = [
     corePlugins['directionVariants'],
     corePlugins['reducedMotionVariants'],
@@ -445,17 +448,28 @@ function registerPlugins(plugins, context) {
   }
 
   reservedBits += 3n
-  context.variantOrder = variantList.reduce(
-    (map, variant, i) => map.set(variant, (1n << BigInt(i)) << reservedBits),
-    new Map()
+
+  let offset = 0
+  context.variantOrder = new Map(
+    variantList
+      .map((variant, i) => {
+        let variantFunctions = variantMap.get(variant).length
+        let bits = (1n << BigInt(i + offset)) << reservedBits
+        offset += variantFunctions - 1
+        return [variant, bits]
+      })
+      .sort(([, a], [, z]) => bigSign(a - z))
   )
 
   context.minimumScreen = [...context.variantOrder.values()].shift()
 
   // Build variantMap
-  for (let [variantName, variantFunction] of variantMap.entries()) {
+  for (let [variantName, variantFunctions] of variantMap.entries()) {
     let sort = context.variantOrder.get(variantName)
-    context.variantMap.set(variantName, [sort, variantFunction])
+    context.variantMap.set(
+      variantName,
+      variantFunctions.map((variantFunction, idx) => [sort << BigInt(idx), variantFunction])
+    )
   }
 }
 

tests/jit/parallel-variants.test.js

@@ -0,0 +1,70 @@
+import postcss from 'postcss'
+import path from 'path'
+import tailwind from '../../src/jit/index.js'
+import { transformAllSelectors, updateAllClasses } from '../../src/util/pluginUtils.js'
+
+function run(input, config = {}) {
+  const { currentTestName } = expect.getState()
+
+  return postcss(tailwind(config)).process(input, {
+    from: `${path.resolve(__filename)}?test=${currentTestName}`,
+  })
+}
+
+test('basic parallel variants', async () => {
+  let config = {
+    mode: 'jit',
+    purge: [
+      {
+        raw: '<div class="font-normal hover:test:font-black test:font-bold test:font-medium"></div>',
+      },
+    ],
+    theme: {},
+    plugins: [
+      function test({ addVariant, config }) {
+        addVariant('test', [
+          transformAllSelectors((selector) => {
+            let variantSelector = updateAllClasses(selector, (className) => {
+              return `test${config('separator')}${className}`
+            })
+
+            return `${variantSelector} *::test`
+          }),
+          transformAllSelectors((selector) => {
+            return updateAllClasses(selector, (className, { withPseudo }) => {
+              return withPseudo(`test${config('separator')}${className}`, '::test')
+            })
+          }),
+        ])
+      },
+    ],
+  }
+
+  let css = `@tailwind utilities`
+
+  return run(css, config).then((result) => {
+    expect(result.css).toMatchFormattedCss(`
+      .font-normal {
+        font-weight: 400;
+      }
+      .test\\:font-bold *::test {
+        font-weight: 700;
+      }
+      .test\\:font-medium *::test {
+        font-weight: 500;
+      }
+      .hover\\:test\\:font-black:hover *::test {
+        font-weight: 900;
+      }
+      .test\\:font-bold::test {
+        font-weight: 700;
+      }
+      .test\\:font-medium::test {
+        font-weight: 500;
+      }
+      .hover\\:test\\:font-black:hover::test {
+        font-weight: 900;
+      }
+    `)
+  })
+})