split.ts — tailwindcss Source File

Source Code

import postcss from 'postcss'
import { DefaultMap } from '../../../../tailwindcss/src/utils/default-map'
import { Stylesheet, type StylesheetId } from '../../stylesheet'
import { walk, WalkAction } from '../../utils/walk'

export async function split(stylesheets: Stylesheet[]) {
  let stylesheetsById = new Map<StylesheetId, Stylesheet>()
  let stylesheetsByFile = new Map<string, Stylesheet>()

  for (let sheet of stylesheets) {
    stylesheetsById.set(sheet.id, sheet)

    if (sheet.file) {
      stylesheetsByFile.set(sheet.file, sheet)
    }
  }

  // Keep track of sheets that contain `@utility` rules
  let requiresSplit = new Set<Stylesheet>()

  for (let sheet of stylesheets) {
    // Root files don't need to be split
    if (sheet.isTailwindRoot) continue

    let containsUtility = false
    let containsUnsafe = sheet.layers().size > 0

    walk(sheet.root, (node) => {
      if (node.type === 'atrule' && node.name === 'utility') {
        containsUtility = true
      }

      // Safe to keep without splitting
      else if (
        // An `@import "…" layer(…)` is safe
        (node.type === 'atrule' && node.name === 'import' && node.params.includes('layer(')) ||
        // @layer blocks are safe
        (node.type === 'atrule' && node.name === 'layer') ||
        // Comments are safe
        node.type === 'comment'
      ) {
        return WalkAction.Skip
      }

      // Everything else is not safe, and requires a split
      else {
        containsUnsafe = true
      }

      // We already know we need to split this sheet
      if (containsUtility && containsUnsafe) {
        return WalkAction.Stop
      }

      return WalkAction.Skip
    })

    if (containsUtility && containsUnsafe) {
      requiresSplit.add(sheet)
    }
// ... (198 more lines)