Function createFormatValidator

packages/cli/src/utils/format-validator.ts:33–51

(
  allowedFormats: readonly T[],
  aliases?: Record<string, T>
)

  aliases?: Record<string, T>
): (value: string) => T
export function createFormatValidator<T extends string>(
  allowedFormats: readonly T[],
  aliases?: Record<string, T>
): (value: string) => T {
  return (value: string): T => {
    const resolved = aliases?.[value] ?? value

    if (!allowedFormats.includes(resolved as T)) {
      const aliasesForAllowed = aliases
        ? Object.entries(aliases)
            .filter(([_, canonical]) => allowedFormats.includes(canonical as T))
            .map(([alias]) => alias)
        : []
      const validValues = [...allowedFormats, ...aliasesForAllowed].join(', ')
      throw new Error(`Invalid output format: ${value}. Valid formats: ${validValues}`)
    }
    return resolved as T
  }
}