Function isBuiltinFormatter

packages/cli-lib/compile.ts:115–119

(
  format: string | Formatter<unknown>
)

}

function isBuiltinFormatter(
  format: string | Formatter<unknown>
): format is string {
  return typeof format === 'string' && BUILTIN_FORMATTERS.has(format)
}

async function compileWithCustomFormatter(
  inputFiles: string[],