migratePrefix() — tailwindcss Function Reference

Source Code

packages/@tailwindcss-upgrade/src/codemods/template/migrate-prefix.ts lines 10–62

export function migratePrefix(
  designSystem: DesignSystem,
  userConfig: Config | null,
  rawCandidate: string,
): string {
  if (!designSystem.theme.prefix) return rawCandidate
  if (!userConfig) return rawCandidate
  if (!version.isMajor(3)) return rawCandidate

  if (!seenDesignSystems.has(designSystem)) {
    designSystem.utilities.functional('group', (value) => [
      // To ensure that `@apply group` works when computing a signature
      decl('--phantom-class', 'group'),
      // To ensure `group` and `group/foo` are considered different classes
      decl('--phantom-modifier', value.modifier?.value),
    ])
    designSystem.utilities.functional('peer', (value) => [
      // To ensure that `@apply peer` works when computing a signature
      decl('--phantom-class', 'peer'),
      // To ensure `peer` and `peer/foo` are considered different classes
      decl('--phantom-modifier', value.modifier?.value),
    ])
    seenDesignSystems.add(designSystem)
  }

  let v3Base = extractV3Base(designSystem, userConfig, rawCandidate)

  if (!v3Base) return rawCandidate

  // Only migrate candidates which are valid in v4
  let originalPrefix = designSystem.theme.prefix
  let candidate: Candidate | null = null
  try {
    designSystem.theme.prefix = null

    let unprefixedCandidate =
      rawCandidate.slice(0, v3Base.start) + v3Base.base + rawCandidate.slice(v3Base.end)

    // Note: This is not a valid candidate in the original DesignSystem, so we
    // can not use the `DesignSystem#parseCandidate` API here or otherwise this
    // invalid candidate will be cached.
    let candidates = [...parseCandidate(unprefixedCandidate, designSystem)]
    if (candidates.length > 0) {
      candidate = candidates[0]
    }
  } finally {
    designSystem.theme.prefix = originalPrefix
  }

  if (!candidate) return rawCandidate

  return designSystem.printCandidate(candidate)
}