at-import.ts — tailwindcss Source File

Source Code

import { Features } from '.'
import { atRule, context, type AstNode } from './ast'
import * as CSS from './css-parser'
import * as ValueParser from './value-parser'
import { walk, WalkAction } from './walk'

type LoadStylesheet = (
  id: string,
  basedir: string,
) => Promise<{
  path: string
  base: string
  content: string
}>

export async function substituteAtImports(
  ast: AstNode[],
  base: string,
  loadStylesheet: LoadStylesheet,
  recurseCount = 0,
  track = false,
) {
  let features = Features.None
  let promises: Promise<void>[] = []

  walk(ast, (node) => {
    if (node.kind === 'at-rule' && (node.name === '@import' || node.name === '@reference')) {
      let parsed = parseImportParams(ValueParser.parse(node.params))
      if (parsed === null) return
      if (node.name === '@reference') {
        parsed.media = 'reference'
      }

      features |= Features.AtImport

      let { uri, layer, media, supports } = parsed

      // Skip importing data or remote URIs
      if (uri.startsWith('data:')) return
      if (uri.startsWith('http://') || uri.startsWith('https://')) return

      let contextNode = context({}, [])

      promises.push(
        (async () => {
          // Since we do not have fully resolved paths in core, we can't
          // reliably detect circular imports. Instead, we try to limit the
          // recursion depth to a number that is too large to be reached in
          // practice.
          if (recurseCount > 100) {
            throw new Error(
              `Exceeded maximum recursion depth while resolving \`${uri}\` in \`${base}\`)`,
            )
          }

          let loaded = await loadStylesheet(uri, base)
          let ast = CSS.parse(loaded.content, { from: track ? loaded.path : undefined })
          await substituteAtImports(ast, loaded.base, loadStylesheet, recurseCount + 1, track)

          contextNode.nodes = buildImportNodes(
// ... (119 more lines)