migrateSimpleLegacyClasses() — tailwindcss Function Reference

Architecture documentation for the migrateSimpleLegacyClasses() function in migrate-simple-legacy-classes.ts from the tailwindcss codebase.

Function typescript MigrationSuite TemplateMigration calls 1

Entity Profile

MigrationSuite→ TemplateMigration→ migrateSimpleLegacyClasses() — tailwindcss Function Reference

Dependency Diagram

graph TD
  076e225f_0c49_c0b1_fd74_16773b08019f["migrateSimpleLegacyClasses()"]
  91c7b7d7_b75e_448f_492f_b7e96c0ac0c5["isMajor()"]
  076e225f_0c49_c0b1_fd74_16773b08019f -->|calls| 91c7b7d7_b75e_448f_492f_b7e96c0ac0c5
  style 076e225f_0c49_c0b1_fd74_16773b08019f fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/@tailwindcss-upgrade/src/codemods/template/migrate-simple-legacy-classes.ts lines 31–63

export function migrateSimpleLegacyClasses(
  designSystem: DesignSystem,
  _userConfig: Config | null,
  rawCandidate: string,
): string {
  // `outline-none` in v3 has the same meaning as `outline-hidden` in v4. However,
  // `outline-none` in v4 _also_ exists but has a different meaning.
  //
  // We can only migrate `outline-none` to `outline-hidden` if we are migrating a
  // v3 project to v4.
  if (version.isMajor(3)) {
    LEGACY_CLASS_MAP['outline-none'] = 'outline-hidden'
  }

  // Prepare design system with the unknown legacy classes
  if (!seenDesignSystems.has(designSystem)) {
    for (let old in LEGACY_CLASS_MAP) {
      designSystem.utilities.static(old, () => [])
    }
    seenDesignSystems.add(designSystem)
  }

  for (let candidate of designSystem.parseCandidate(rawCandidate)) {
    if (candidate.kind === 'static' && Object.hasOwn(LEGACY_CLASS_MAP, candidate.root)) {
      return designSystem.printCandidate({
        ...candidate,
        root: LEGACY_CLASS_MAP[candidate.root as keyof typeof LEGACY_CLASS_MAP],
      })
    }
  }

  return rawCandidate
}