tailwindcss/tests/important-boolean.test.js

import fs from 'fs'
import path from 'path'
import * as sharedState from '../src/lib/sharedState'

import { crosscheck, run, html, css, defaults } from './util/run'

crosscheck(() => {
  test('important boolean', () => {
    let config = {
      important: true,
      darkMode: 'class',
      content: [
        {
          raw: html`
            <div class="container"></div>
            <div class="btn"></div>
            <div class="animate-spin"></div>
            <div class="custom-util"></div>
            <div class="custom-component"></div>
            <div class="custom-important-component"></div>
            <div class="font-bold"></div>
            <div class="md:hover:text-right"></div>
            <div class="motion-safe:hover:text-center"></div>
            <div class="dark:focus:text-left"></div>
            <div class="group-hover:focus-within:text-left"></div>
            <div class="rtl:active:text-center"></div>
          `,
        },
      ],
      corePlugins: { preflight: false },
      plugins: [
        function ({ addComponents, addUtilities }) {
          addComponents(
            {
              '.btn': {
                button: 'yes',
              },
            },
            { respectImportant: true }
          )
          addComponents(
            {
              '@font-face': {
                'font-family': 'Inter',
              },
              '@page': {
                margin: '1cm',
              },
            },
            { respectImportant: true }
          )
          addUtilities(
            {
              '.custom-util': {
                button: 'no',
              },
            },
            { respectImportant: false }
          )
        },
      ],
    }

    let input = css`
      @tailwind base;
      @tailwind components;
      @layer components {
        .custom-component {
          @apply font-bold;
        }
        .custom-important-component {
          @apply text-center !important;
        }
      }
      @tailwind utilities;
    `

    return run(input, config).then((result) => {
      expect(result.css).toMatchFormattedCss(css`
        ${defaults}
        .container {
          width: 100%;
        }
        @media (min-width: 640px) {
          .container {
            max-width: 640px;
          }
        }
        @media (min-width: 768px) {
          .container {
            max-width: 768px;
          }
        }
        @media (min-width: 1024px) {
          .container {
            max-width: 1024px;
          }
        }
        @media (min-width: 1280px) {
          .container {
            max-width: 1280px;
          }
        }
        @media (min-width: 1536px) {
          .container {
            max-width: 1536px;
          }
        }
        .btn {
          button: yes !important;
        }
        @font-face {
          font-family: Inter;
        }
        @page {
          margin: 1cm;
        }
        .custom-component {
          font-weight: 700;
        }
        .custom-important-component {
          text-align: center !important;
        }
        @keyframes spin {
          to {
            transform: rotate(360deg);
          }
        }
        .animate-spin {
          animation: 1s linear infinite spin !important;
        }
        .font-bold {
          font-weight: 700 !important;
        }
        .custom-util {
          button: no;
        }
        .group:hover .group-hover\:focus-within\:text-left:focus-within {
          text-align: left !important;
        }
        [dir='rtl'] .rtl\:active\:text-center:active {
          text-align: center !important;
        }
        @media (prefers-reduced-motion: no-preference) {
          .motion-safe\:hover\:text-center:hover {
            text-align: center !important;
          }
        }
        .dark .dark\:focus\:text-left:focus {
          text-align: left !important;
        }
        @media (min-width: 768px) {
          .md\:hover\:text-right:hover {
            text-align: right !important;
          }
        }
      `)
    })
  })

  // This is in a describe block so we can use `afterEach` :)
  describe('duplicate elision', () => {
    let filePath = path.resolve(__dirname, './important-boolean-duplicates.test.html')

    afterEach(async () => await fs.promises.unlink(filePath))

    test('important rules are not duplicated when rebuilding', async () => {
      let config = {
        important: true,
        content: [filePath],
      }

      await fs.promises.writeFile(
        config.content[0],
        html`
          <div class="ml-2"></div>
          <div class="ml-4"></div>
        `
      )

      let input = css`
        @tailwind utilities;
      `

      let result = await run(input, config)
      let allContexts = Array.from(sharedState.contextMap.values())

      let context = allContexts[allContexts.length - 1]

      let ruleCacheSize1 = context.ruleCache.size

      expect(result.css).toMatchFormattedCss(css`
        .ml-2 {
          margin-left: 0.5rem !important;
        }
        .ml-4 {
          margin-left: 1rem !important;
        }
      `)

      await fs.promises.writeFile(
        config.content[0],
        html`
          <div class="ml-2"></div>
          <div class="ml-6"></div>
        `
      )

      result = await run(input, config)

      let ruleCacheSize2 = context.ruleCache.size

      expect(result.css).toMatchFormattedCss(css`
        .ml-2 {
          margin-left: 0.5rem !important;
        }
        .ml-4 {
          margin-left: 1rem !important;
        }
        .ml-6 {
          margin-left: 1.5rem !important;
        }
      `)

      // The rule cache was effectively doubling in size previously
      // because the rule cache was never de-duped
      // This ensures this behavior doesn't return
      expect(ruleCacheSize2 - ruleCacheSize1).toBeLessThan(10)
    })
  })
})