File size: 1,360 Bytes
5fae594 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 |
import type { Nullable } from '../utils';
/**
* Transforms a domain name into a canonical domain name. The canonical domain name is a domain name
* that has been trimmed, lowercased, stripped of leading dot, and optionally punycode-encoded
* ({@link https://www.rfc-editor.org/rfc/rfc6265.html#section-5.1.2 | Section 5.1.2 of RFC 6265}). For
* the most part, this function is idempotent (calling the function with the output from a previous call
* returns the same output).
*
* @remarks
* A canonicalized host name is the string generated by the following
* algorithm:
*
* 1. Convert the host name to a sequence of individual domain name
* labels.
*
* 2. Convert each label that is not a Non-Reserved LDH (NR-LDH) label,
* to an A-label (see Section 2.3.2.1 of [RFC5890] for the former
* and latter), or to a "punycode label" (a label resulting from the
* "ToASCII" conversion in Section 4 of [RFC3490]), as appropriate
* (see Section 6.3 of this specification).
*
* 3. Concatenate the resulting labels, separated by a %x2E (".")
* character.
*
* @example
* ```
* canonicalDomain('.EXAMPLE.com') === 'example.com'
* ```
*
* @param domainName - the domain name to generate the canonical domain from
* @public
*/
export declare function canonicalDomain(domainName: Nullable<string>): string | undefined;
|