Add support for Tailwind v3.1

README.md

@@ -16,7 +16,7 @@ twMerge('px-2 py-1 bg-red hover:bg-dark-red', 'p-3 bg-[#B91C1C]')
 // → 'hover:bg-dark-red p-3 bg-[#B91C1C]'
 ```
 
--   Supports Tailwind v3.0 (if you use Tailwind v2, use [tailwind-merge v0.9.0](https://github.com/dcastil/tailwind-merge/tree/v0.9.0))
+-   Supports Tailwind v3.0 up to v3.1 (if you use Tailwind v2, use [tailwind-merge v0.9.0](https://github.com/dcastil/tailwind-merge/tree/v0.9.0))
 -   Works in Node >=12 and all modern browsers
 -   Fully typed
 -   [Check bundle size on Bundlephobia](https://bundlephobia.com/package/tailwind-merge)
@@ -114,6 +114,19 @@ twMerge('[padding:1rem] p-8') // → '[padding:1rem] p-8'
 
 Watch out for mixing arbitrary properties which could be expressed as Tailwind classes. tailwind-merge does not resolve conflicts between arbitrary properties and their matching Tailwind classes to keep the bundle size small.
 
+### Supports arbitrary variants
+
+```ts
+twMerge('[&:nth-child(3)]:py-0 [&:nth-child(3)]:py-4') // → '[&:nth-child(3)]:py-4'
+twMerge('dark:hover:[&:nth-child(3)]:py-0 hover:dark:[&:nth-child(3)]:py-4')
+// → 'hover:dark:[&:nth-child(3)]:py-4'
+
+// Don't do this!
+twMerge('[&:focus]:ring focus:ring-4') // → '[&:focus]:ring focus:ring-4'
+```
+
+Similarly to arbitrary properties, tailwind-merge does not resolve conflicts between arbitrary variants and their matching predefined modifiers for bundle size reasons.
+
 ### Supports important modifier
 
 ```ts

src/lib/default-config.ts

@@ -20,6 +20,7 @@ export function getDefaultConfig() {
     const brightness = fromTheme('brightness')
     const borderColor = fromTheme('borderColor')
     const borderRadius = fromTheme('borderRadius')
+    const borderSpacing = fromTheme('borderSpacing')
     const borderWidth = fromTheme('borderWidth')
     const contrast = fromTheme('contrast')
     const grayscale = fromTheme('grayscale')
@@ -74,6 +75,7 @@ export function getDefaultConfig() {
             'saturation',
             'color',
             'luminosity',
+            'plus-lighter',
         ] as const
     const getAlign = () => ['start', 'end', 'center', 'between', 'around', 'evenly'] as const
     const getZeroAndEmpty = () => ['', '0', isArbitraryValue] as const
@@ -89,6 +91,7 @@ export function getDefaultConfig() {
             brightness: [isInteger],
             borderColor: [colors],
             borderRadius: ['none', '', 'full', isTshirtSize, isArbitraryLength],
+            borderSpacing: [spacing],
             borderWidth: getLengthWithEmpty(),
             contrast: [isInteger],
             grayscale: getZeroAndEmpty(),
@@ -361,7 +364,7 @@ export function getDefaultConfig() {
              * Grid Auto Flow
              * @see https://tailwindcss.com/docs/grid-auto-flow
              */
-            'grid-flow': [{ 'grid-flow': ['row', 'col', 'row-dense', 'col-dense'] }],
+            'grid-flow': [{ 'grid-flow': ['row', 'col', 'dense', 'row-dense', 'col-dense'] }],
             /**
              * Grid Auto Columns
              * @see https://tailwindcss.com/docs/grid-auto-columns
@@ -689,7 +692,7 @@ export function getDefaultConfig() {
              * Text Alignment
              * @see https://tailwindcss.com/docs/text-align
              */
-            'text-alignment': [{ text: ['left', 'center', 'right', 'justify'] }],
+            'text-alignment': [{ text: ['left', 'center', 'right', 'justify', 'start', 'end'] }],
             /**
              * Text Color
              * @see https://tailwindcss.com/docs/text-color
@@ -1190,6 +1193,21 @@ export function getDefaultConfig() {
              * @see https://tailwindcss.com/docs/border-collapse
              */
             'border-collapse': [{ border: ['collapse', 'separate'] }],
+            /**
+             * Border Spacing
+             * @see https://tailwindcss.com/docs/border-spacing
+             */
+            'border-spacing': [{ 'border-spacing': [borderSpacing] }],
+            /**
+             * Border Spacing X
+             * @see https://tailwindcss.com/docs/border-spacing
+             */
+            'border-spacing-x': [{ 'border-spacing-x': [borderSpacing] }],
+            /**
+             * Border Spacing Y
+             * @see https://tailwindcss.com/docs/border-spacing
+             */
+            'border-spacing-y': [{ 'border-spacing-y': [borderSpacing] }],
             /**
              * Table Layout
              * @see https://tailwindcss.com/docs/table-layout
@@ -1561,6 +1579,7 @@ export function getDefaultConfig() {
             'rounded-r': ['rounded-tr', 'rounded-br'],
             'rounded-b': ['rounded-br', 'rounded-bl'],
             'rounded-l': ['rounded-tl', 'rounded-bl'],
+            'border-spacing': ['border-spacing-x', 'border-spacing-y'],
             'border-w': ['border-w-t', 'border-w-r', 'border-w-b', 'border-w-l'],
             'border-w-x': ['border-w-r', 'border-w-l'],
             'border-w-y': ['border-w-t', 'border-w-b'],

src/lib/merge-classlist.ts

@@ -2,10 +2,6 @@ import { ConfigUtils } from './config-utils'
 
 const SPLIT_CLASSES_REGEX = /\s+/
 const IMPORTANT_MODIFIER = '!'
-// Regex is needed, so we don't match against colons in labels for arbitrary values like `text-[color:var(--mystery-var)]`
-// I'd prefer to use a negative lookbehind for all supported labels, but lookbehinds don't have good browser support yet. More info: https://caniuse.com/js-regexp-lookbehind
-const MODIFIER_SEPARATOR_REGEX = /:(?![^[]*\])/
-const MODIFIER_SEPARATOR = ':'
 
 export function mergeClassList(classList: string, configUtils: ConfigUtils) {
     const { getClassGroupId, getConflictingClassGroupIds } = configUtils
@@ -15,7 +11,7 @@ export function mergeClassList(classList: string, configUtils: ConfigUtils) {
      * `{importantModifier}{variantModifiers}{classGroupId}`
      * @example 'float'
      * @example 'hover:focus:bg-color'
-     * @example '!md:pr'
+     * @example 'md:!pr'
      */
     const classGroupsInConflict = new Set<string>()
 
@@ -24,16 +20,10 @@ export function mergeClassList(classList: string, configUtils: ConfigUtils) {
             .trim()
             .split(SPLIT_CLASSES_REGEX)
             .map((originalClassName) => {
-                const modifiers = originalClassName.split(MODIFIER_SEPARATOR_REGEX)
-                const classNameWithImportantModifier = modifiers.pop()!
+                const { modifiers, hasImportantModifier, baseClassName } =
+                    splitModifiers(originalClassName)
 
-                const hasImportantModifier =
-                    classNameWithImportantModifier.startsWith(IMPORTANT_MODIFIER)
-                const className = hasImportantModifier
-                    ? classNameWithImportantModifier.substring(1)
-                    : classNameWithImportantModifier
-
-                const classGroupId = getClassGroupId(className)
+                const classGroupId = getClassGroupId(baseClassName)
 
                 if (!classGroupId) {
                     return {
@@ -42,18 +32,15 @@ export function mergeClassList(classList: string, configUtils: ConfigUtils) {
                     }
                 }
 
-                const variantModifier =
-                    modifiers.length === 0
-                        ? ''
-                        : modifiers.sort().concat('').join(MODIFIER_SEPARATOR)
+                const variantModifier = sortModifiers(modifiers).join('')
 
-                const fullModifier = hasImportantModifier
-                    ? IMPORTANT_MODIFIER + variantModifier
+                const modifierId = hasImportantModifier
+                    ? variantModifier + IMPORTANT_MODIFIER
                     : variantModifier
 
                 return {
                     isTailwindClass: true as const,
-                    modifier: fullModifier,
+                    modifierId,
                     classGroupId,
                     originalClassName,
                 }
@@ -65,9 +52,9 @@ export function mergeClassList(classList: string, configUtils: ConfigUtils) {
                     return true
                 }
 
-                const { modifier, classGroupId } = parsed
+                const { modifierId, classGroupId } = parsed
 
-                const classId = `${modifier}:${classGroupId}`
+                const classId = `${modifierId}${classGroupId}`
 
                 if (classGroupsInConflict.has(classId)) {
                     return false
@@ -76,7 +63,7 @@ export function mergeClassList(classList: string, configUtils: ConfigUtils) {
                 classGroupsInConflict.add(classId)
 
                 getConflictingClassGroupIds(classGroupId).forEach((group) =>
-                    classGroupsInConflict.add(`${modifier}:${group}`)
+                    classGroupsInConflict.add(`${modifierId}${group}`)
                 )
 
                 return true
@@ -86,3 +73,66 @@ export function mergeClassList(classList: string, configUtils: ConfigUtils) {
             .join(' ')
     )
 }
+
+function splitModifiers(className: string) {
+    const modifiers = []
+
+    let bracketDepth = 0
+    let modifierStart = 0
+
+    for (const match of className.matchAll(/[:[\]]/g)) {
+        if (match[0] === ':') {
+            if (bracketDepth === 0) {
+                const nextModifierStart = match.index! + 1
+                modifiers.push(className.substring(modifierStart, nextModifierStart))
+                modifierStart = nextModifierStart
+            }
+        } else if (match[0] === '[') {
+            bracketDepth++
+        } else if (match[0] === ']') {
+            bracketDepth--
+        }
+    }
+
+    const baseClassNameWithImportantModifier =
+        modifiers.length === 0 ? className : className.substring(modifierStart)
+    const hasImportantModifier = baseClassNameWithImportantModifier.startsWith(IMPORTANT_MODIFIER)
+    const baseClassName = hasImportantModifier
+        ? baseClassNameWithImportantModifier.substring(1)
+        : baseClassNameWithImportantModifier
+
+    return {
+        modifiers,
+        hasImportantModifier,
+        baseClassName,
+    }
+}
+
+/**
+ * Sorts modifiers according to following schema:
+ * - Predefined modifiers are sorted alphabetically
+ * - When an arbitrary variant appears, it's important to preserve which modifiers are before and after it
+ */
+function sortModifiers(modifiers: string[]) {
+    if (modifiers.length <= 1) {
+        return modifiers
+    }
+
+    const sortedModifiers = []
+    let unsortedModifiers: string[] = []
+
+    modifiers.forEach((modifier) => {
+        const isArbitraryVariant = modifier[0] === '['
+
+        if (isArbitraryVariant) {
+            sortedModifiers.push(...unsortedModifiers.sort(), modifier)
+            unsortedModifiers = []
+        } else {
+            unsortedModifiers.push(modifier)
+        }
+    })
+
+    sortedModifiers.push(...unsortedModifiers.sort())
+
+    return sortedModifiers
+}

tests/arbitrary-variants.test.ts

@@ -0,0 +1,83 @@
+import { twMerge } from '../src'
+
+test('basic arbitrary variants', () => {
+    expect(twMerge('[&>*]:underline [&>*]:line-through')).toBe('[&>*]:line-through')
+    expect(twMerge('[&>*]:underline [&>*]:line-through [&_div]:line-through')).toBe(
+        '[&>*]:line-through [&_div]:line-through'
+    )
+})
+
+test('arbitrary variants with modifiers', () => {
+    expect(twMerge('dark:lg:hover:[&>*]:underline dark:lg:hover:[&>*]:line-through')).toBe(
+        'dark:lg:hover:[&>*]:line-through'
+    )
+    expect(twMerge('dark:lg:hover:[&>*]:underline dark:hover:lg:[&>*]:line-through')).toBe(
+        'dark:hover:lg:[&>*]:line-through'
+    )
+    // Whether a modifier is before or after arbitrary variant matters
+    expect(twMerge('hover:[&>*]:underline [&>*]:hover:line-through')).toBe(
+        'hover:[&>*]:underline [&>*]:hover:line-through'
+    )
+    expect(
+        twMerge(
+            'hover:dark:[&>*]:underline dark:hover:[&>*]:underline dark:[&>*]:hover:line-through'
+        )
+    ).toBe('dark:hover:[&>*]:underline dark:[&>*]:hover:line-through')
+})
+
+test('arbitrary variants with complex syntax in them', () => {
+    expect(
+        twMerge(
+            '[@media_screen{@media(hover:hover)}]:underline [@media_screen{@media(hover:hover)}]:line-through'
+        )
+    ).toBe('[@media_screen{@media(hover:hover)}]:line-through')
+    expect(
+        twMerge(
+            'hover:[@media_screen{@media(hover:hover)}]:underline hover:[@media_screen{@media(hover:hover)}]:line-through'
+        )
+    ).toBe('hover:[@media_screen{@media(hover:hover)}]:line-through')
+})
+
+test('arbitrary variants with attribute selectors', () => {
+    expect(twMerge('[&[data-open]]:underline [&[data-open]]:line-through')).toBe(
+        '[&[data-open]]:line-through'
+    )
+})
+
+test('arbitrary variants with multiple attribute selectors', () => {
+    expect(
+        twMerge(
+            '[&[data-foo][data-bar]:not([data-baz])]:underline [&[data-foo][data-bar]:not([data-baz])]:line-through'
+        )
+    ).toBe('[&[data-foo][data-bar]:not([data-baz])]:line-through')
+})
+
+test('multiple arbitrary variants', () => {
+    expect(twMerge('[&>*]:[&_div]:underline [&>*]:[&_div]:line-through')).toBe(
+        '[&>*]:[&_div]:line-through'
+    )
+    expect(twMerge('[&>*]:[&_div]:underline [&_div]:[&>*]:line-through')).toBe(
+        '[&>*]:[&_div]:underline [&_div]:[&>*]:line-through'
+    )
+    expect(
+        twMerge(
+            'hover:dark:[&>*]:focus:disabled:[&_div]:underline dark:hover:[&>*]:disabled:focus:[&_div]:line-through'
+        )
+    ).toBe('dark:hover:[&>*]:disabled:focus:[&_div]:line-through')
+    expect(
+        twMerge(
+            'hover:dark:[&>*]:focus:[&_div]:disabled:underline dark:hover:[&>*]:disabled:focus:[&_div]:line-through'
+        )
+    ).toBe(
+        'hover:dark:[&>*]:focus:[&_div]:disabled:underline dark:hover:[&>*]:disabled:focus:[&_div]:line-through'
+    )
+})
+
+test('arbitrary variants with arbitrary properties', () => {
+    expect(twMerge('[&>*]:[color:red] [&>*]:[color:blue]')).toBe('[&>*]:[color:blue]')
+    expect(
+        twMerge(
+            '[&[data-foo][data-bar]:not([data-baz])]:nod:noa:[color:red] [&[data-foo][data-bar]:not([data-baz])]:noa:nod:[color:blue]'
+        )
+    ).toBe('[&[data-foo][data-bar]:not([data-baz])]:noa:nod:[color:blue]')
+})

tests/class-map.test.ts

@@ -61,6 +61,9 @@ test('class map has correct class groups at first part', () => {
             'border-color-x',
             'border-color-y',
             'border-opacity',
+            'border-spacing',
+            'border-spacing-x',
+            'border-spacing-y',
             'border-style',
             'border-w',
             'border-w-b',

tests/readme-examples.test.ts

@@ -3,10 +3,10 @@ import fs from 'fs'
 import { twMerge } from '../src'
 
 const twMergeExampleRegex =
-    /twMerge\((?<arguments>[\w\s\-:[\]#(),!\n'"]+?)\)(?!.*(?<!\/\/.*)')\s*\n?\s*\/\/\s*→\s*['"](?<result>.+)['"]/g
+    /twMerge\((?<arguments>[\w\s\-:[\]#(),!&\n'"]+?)\)(?!.*(?<!\/\/.*)')\s*\n?\s*\/\/\s*→\s*['"](?<result>.+)['"]/g
 
 test('readme examples', () => {
-    expect.assertions(21)
+    expect.assertions(24)
 
     return fs.promises
         .readFile(`${__dirname}/../README.md`, { encoding: 'utf-8' })