Function parseOptions

source/rate-limit.ts:154–313

(passedOptions: Partial<Options>)

 * @returns {Configuration} - A complete configuration object.
 */
const parseOptions = (passedOptions: Partial<Options>): Configuration => {
	// Passing undefined should be equivalent to not passing an option at all, so we'll
	// omit all fields where their value is undefined.
	const notUndefinedOptions: Partial<Options> =
		omitUndefinedProperties<Partial<Options>>(passedOptions)

	const logger = passedOptions.logger ?? ConsoleLogger

	// Create the validator before even parsing the rest of the options.
	const validations = getValidations(
		notUndefinedOptions?.validate ?? true,
		logger,
	)
	validations.validationsConfig()

	// Warn on unknown options
	validations.knownOptions(passedOptions)

	// Warn for the deprecated options. Note that these options have been removed
	// from the type definitions in v7.
	validations.draftPolliHeaders(
		// @ts-expect-error see the note above.
		notUndefinedOptions.draft_polli_ratelimit_headers,
	)
	// @ts-expect-error see the note above.
	validations.onLimitReached(notUndefinedOptions.onLimitReached)

	// If ipv6Subnet is set to anything other than a function, check it now
	// (if it's a function, we'll check the output value later)
	if (
		notUndefinedOptions.ipv6Subnet !== undefined &&
		typeof notUndefinedOptions.ipv6Subnet !== 'function'
	) {
		validations.ipv6Subnet(notUndefinedOptions.ipv6Subnet)
	}

	// Warn for custom keyGenerator that uses req.ip without the ipKeyGenerator helper
	validations.keyGeneratorIpFallback(notUndefinedOptions.keyGenerator)

	// Warn for incompatible settings
	validations.ipv6SubnetOrKeyGenerator(notUndefinedOptions)

	// The default value for the `standardHeaders` option is `false`. If set to
	// `true`, it resolve to `draft-6`. `draft-7` and draft-8` (recommended) are
	// used only if explicitly set.
	let standardHeaders = notUndefinedOptions.standardHeaders ?? false
	if (standardHeaders === true) standardHeaders = 'draft-6'

	// See ./types.ts#Options for a detailed description of the options and their
	// defaults.
	const config: Configuration = {
		windowMs: 60 * 1000,
		limit: passedOptions.max ?? 5, // `max` is deprecated, but support it anyways.
		message: 'Too many requests, please try again later.',
		statusCode: 429,
		legacyHeaders: passedOptions.headers ?? true,
		identifier(request: Request, _response: Response): string {
			let duration = ''