add arbitrary value support & tests

jest/customMatchers.js

@@ -0,0 +1,146 @@
+const prettier = require('prettier')
+const { diff } = require('jest-diff')
+
+function format(input) {
+  return prettier.format(input, {
+    parser: 'css',
+    printWidth: 100,
+  })
+}
+
+expect.extend({
+  // Compare two CSS strings with all whitespace removed
+  // This is probably naive but it's fast and works well enough.
+  toMatchCss(received, argument) {
+    function stripped(str) {
+      return str.replace(/\s/g, '').replace(/;/g, '')
+    }
+
+    const options = {
+      comment: 'stripped(received) === stripped(argument)',
+      isNot: this.isNot,
+      promise: this.promise,
+    }
+
+    const pass = stripped(received) === stripped(argument)
+
+    const message = pass
+      ? () => {
+        return (
+          this.utils.matcherHint('toMatchCss', undefined, undefined, options) +
+          '\n\n' +
+          `Expected: not ${this.utils.printExpected(format(received))}\n` +
+          `Received: ${this.utils.printReceived(format(argument))}`
+        )
+      }
+      : () => {
+        const actual = format(received)
+        const expected = format(argument)
+
+        const diffString = diff(expected, actual, {
+          expand: this.expand,
+        })
+
+        return (
+          this.utils.matcherHint('toMatchCss', undefined, undefined, options) +
+          '\n\n' +
+          (diffString && diffString.includes('- Expect')
+            ? `Difference:\n\n${diffString}`
+            : `Expected: ${this.utils.printExpected(expected)}\n` +
+            `Received: ${this.utils.printReceived(actual)}`)
+        )
+      }
+
+    return { actual: received, message, pass }
+  },
+  toIncludeCss(received, argument) {
+    const options = {
+      comment: 'stripped(received).includes(stripped(argument))',
+      isNot: this.isNot,
+      promise: this.promise,
+    }
+
+    const actual = format(received)
+    const expected = format(argument)
+
+    const pass = actual.includes(expected)
+
+    const message = pass
+      ? () => {
+        return (
+          this.utils.matcherHint('toIncludeCss', undefined, undefined, options) +
+          '\n\n' +
+          `Expected: not ${this.utils.printExpected(format(received))}\n` +
+          `Received: ${this.utils.printReceived(format(argument))}`
+        )
+      }
+      : () => {
+        const diffString = diff(expected, actual, {
+          expand: this.expand,
+        })
+
+        return (
+          this.utils.matcherHint('toIncludeCss', undefined, undefined, options) +
+          '\n\n' +
+          (diffString && diffString.includes('- Expect')
+            ? `Difference:\n\n${diffString}`
+            : `Expected: ${this.utils.printExpected(expected)}\n` +
+            `Received: ${this.utils.printReceived(actual)}`)
+        )
+      }
+
+    return { actual: received, message, pass }
+  },
+})
+
+expect.extend({
+  // Compare two CSS strings with all whitespace removed
+  // This is probably naive but it's fast and works well enough.
+  toMatchFormattedCss(received, argument) {
+    function format(input) {
+      return prettier.format(input.replace(/\n/g, ''), {
+        parser: 'css',
+        printWidth: 100,
+      })
+    }
+    const options = {
+      comment: 'stripped(received) === stripped(argument)',
+      isNot: this.isNot,
+      promise: this.promise,
+    }
+
+    let formattedReceived = format(received)
+    let formattedArgument = format(argument)
+
+    const pass = formattedReceived === formattedArgument
+
+    const message = pass
+      ? () => {
+        return (
+          this.utils.matcherHint('toMatchCss', undefined, undefined, options) +
+          '\n\n' +
+          `Expected: not ${this.utils.printExpected(formattedReceived)}\n` +
+          `Received: ${this.utils.printReceived(formattedArgument)}`
+        )
+      }
+      : () => {
+        const actual = formattedReceived
+        const expected = formattedArgument
+
+        const diffString = diff(expected, actual, {
+          expand: this.expand,
+        })
+
+        return (
+          this.utils.matcherHint('toMatchCss', undefined, undefined, options) +
+          '\n\n' +
+          (diffString && diffString.includes('- Expect')
+            ? `Difference:\n\n${diffString}`
+            : `Expected: ${this.utils.printExpected(expected)}\n` +
+            `Received: ${this.utils.printReceived(actual)}`)
+        )
+      }
+
+    return { actual: received, message, pass }
+  },
+})

package.json

@@ -13,7 +13,20 @@
     "singleQuote": true,
     "trailingComma": "es5"
   },
+  "scripts": {
+    "test": "jest"
+  },
+  "devDependencies": {
+    "jest": "^27.4.4",
+    "postcss": "^8.2.2",
+    "prettier": "^2.5.1"
+  },
   "peerDependencies": {
     "tailwindcss": ">=2.0.0 || >=3.0.0 || >=3.0.0-alpha.1"
+  },
+  "jest": {
+    "setupFilesAfterEnv": [
+      "<rootDir>/jest/customMatchers.js"
+    ]
   }
 }

src/index.js

@@ -1,21 +1,27 @@
 const plugin = require('tailwindcss/plugin')
 
+const baseStyles = {
+  overflow: 'hidden',
+  display: '-webkit-box',
+  '-webkit-box-orient': 'vertical',
+}
+
 const lineClamp = plugin(
-  function ({ addUtilities, theme, variants, e }) {
+  function ({ matchUtilities, addUtilities, theme, variants, e }) {
     const values = theme('lineClamp')
 
+    matchUtilities(
+      {
+        'line-clamp': (value) => ({
+          ...baseStyles,
+          '-webkit-line-clamp': `${value}`,
+        })
+      },
+      { values }
+    )
+
     addUtilities(
       [
-        Object.entries(values).map(([key, value]) => {
-          return {
-            [`.${e(`line-clamp-${key}`)}`]: {
-              overflow: 'hidden',
-              display: '-webkit-box',
-              '-webkit-box-orient': 'vertical',
-              '-webkit-line-clamp': `${value}`,
-            },
-          }
-        }),
         {
           '.line-clamp-none': {
             '-webkit-line-clamp': 'unset',

src/index.test.js

@@ -0,0 +1,61 @@
+const path = require('path')
+const postcss = require('postcss')
+const tailwindcss = require('tailwindcss')
+const lineClampPlugin = require('.')
+
+function run(config, plugin = tailwindcss) {
+  let { currentTestName } = expect.getState()
+  config = {
+    ...{ plugins: [lineClampPlugin], corePlugins: { preflight: false } },
+    ...config,
+  }
+
+  return postcss(plugin(config)).process('@tailwind utilities', {
+    from: `${path.resolve(__filename)}?test=${currentTestName}`,
+  })
+}
+
+it('should add the `line-clamp-{n}` components', () => {
+  const config = {
+    content: [{ raw: String.raw`<div class="line-clamp-2 line-clamp-[33] line-clamp-[var(--line-clamp-variable)]"></div>` }],
+  }
+
+  return run(config).then((result) => {
+    expect(result.css).toMatchCss(String.raw`
+      .line-clamp-2 {
+        overflow: hidden;
+        display: -webkit-box;
+        -webkit-box-orient: vertical;
+        -webkit-line-clamp: 2;
+      }
+
+      .line-clamp-\[33\] {
+        overflow: hidden;
+        display: -webkit-box;
+        -webkit-box-orient: vertical;
+        -webkit-line-clamp: 33;
+      }
+
+      .line-clamp-\[var\(--line-clamp-variable\)\] {
+        overflow: hidden;
+        display: -webkit-box;
+        -webkit-box-orient: vertical;
+        -webkit-line-clamp: var(--line-clamp-variable);
+      }
+    `)
+  })
+})
+
+it('should add the `line-clamp-none` utility', () => {
+  const config = {
+    content: [{ raw: String.raw`<div class="line-clamp-none"></div>` }],
+  }
+
+  return run(config).then((result) => {
+    expect(result.css).toMatchCss(String.raw`
+      .line-clamp-none {
+        -webkit-line-clamp: unset;
+      }
+    `)
+  })
+})