diff options
Diffstat (limited to 'vanilla/node_modules/tldts-core/src')
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/domain-without-suffix.ts | 14 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/domain.ts | 100 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/extract-hostname.ts | 170 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/factory.ts | 163 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/is-ip.ts | 87 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/is-valid.ts | 79 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/lookup/fast-path.ts | 80 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/lookup/interface.ts | 10 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/options.ts | 39 | ||||
| -rw-r--r-- | vanilla/node_modules/tldts-core/src/subdomain.ts | 11 |
10 files changed, 753 insertions, 0 deletions
diff --git a/vanilla/node_modules/tldts-core/src/domain-without-suffix.ts b/vanilla/node_modules/tldts-core/src/domain-without-suffix.ts new file mode 100644 index 0000000..9607d4b --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/domain-without-suffix.ts @@ -0,0 +1,14 @@ +/** + * Return the part of domain without suffix. + * + * Example: for domain 'foo.com', the result would be 'foo'. + */ +export default function getDomainWithoutSuffix( + domain: string, + suffix: string, +): string { + // Note: here `domain` and `suffix` cannot have the same length because in + // this case we set `domain` to `null` instead. It is thus safe to assume + // that `suffix` is shorter than `domain`. + return domain.slice(0, -suffix.length - 1); +} diff --git a/vanilla/node_modules/tldts-core/src/domain.ts b/vanilla/node_modules/tldts-core/src/domain.ts new file mode 100644 index 0000000..640d33e --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/domain.ts @@ -0,0 +1,100 @@ +import { IOptions } from './options'; + +/** + * Check if `vhost` is a valid suffix of `hostname` (top-domain) + * + * It means that `vhost` needs to be a suffix of `hostname` and we then need to + * make sure that: either they are equal, or the character preceding `vhost` in + * `hostname` is a '.' (it should not be a partial label). + * + * * hostname = 'not.evil.com' and vhost = 'vil.com' => not ok + * * hostname = 'not.evil.com' and vhost = 'evil.com' => ok + * * hostname = 'not.evil.com' and vhost = 'not.evil.com' => ok + */ +function shareSameDomainSuffix(hostname: string, vhost: string): boolean { + if (hostname.endsWith(vhost)) { + return ( + hostname.length === vhost.length || + hostname[hostname.length - vhost.length - 1] === '.' + ); + } + + return false; +} + +/** + * Given a hostname and its public suffix, extract the general domain. + */ +function extractDomainWithSuffix( + hostname: string, + publicSuffix: string, +): string { + // Locate the index of the last '.' in the part of the `hostname` preceding + // the public suffix. + // + // examples: + // 1. not.evil.co.uk => evil.co.uk + // ^ ^ + // | | start of public suffix + // | index of the last dot + // + // 2. example.co.uk => example.co.uk + // ^ ^ + // | | start of public suffix + // | + // | (-1) no dot found before the public suffix + const publicSuffixIndex = hostname.length - publicSuffix.length - 2; + const lastDotBeforeSuffixIndex = hostname.lastIndexOf('.', publicSuffixIndex); + + // No '.' found, then `hostname` is the general domain (no sub-domain) + if (lastDotBeforeSuffixIndex === -1) { + return hostname; + } + + // Extract the part between the last '.' + return hostname.slice(lastDotBeforeSuffixIndex + 1); +} + +/** + * Detects the domain based on rules and upon and a host string + */ +export default function getDomain( + suffix: string, + hostname: string, + options: IOptions, +): string | null { + // Check if `hostname` ends with a member of `validHosts`. + if (options.validHosts !== null) { + const validHosts = options.validHosts; + for (const vhost of validHosts) { + if (/*@__INLINE__*/ shareSameDomainSuffix(hostname, vhost)) { + return vhost; + } + } + } + + let numberOfLeadingDots = 0; + if (hostname.startsWith('.')) { + while ( + numberOfLeadingDots < hostname.length && + hostname[numberOfLeadingDots] === '.' + ) { + numberOfLeadingDots += 1; + } + } + + // If `hostname` is a valid public suffix, then there is no domain to return. + // Since we already know that `getPublicSuffix` returns a suffix of `hostname` + // there is no need to perform a string comparison and we only compare the + // size. + if (suffix.length === hostname.length - numberOfLeadingDots) { + return null; + } + + // To extract the general domain, we start by identifying the public suffix + // (if any), then consider the domain to be the public suffix with one added + // level of depth. (e.g.: if hostname is `not.evil.co.uk` and public suffix: + // `co.uk`, then we take one more level: `evil`, giving the final result: + // `evil.co.uk`). + return /*@__INLINE__*/ extractDomainWithSuffix(hostname, suffix); +} diff --git a/vanilla/node_modules/tldts-core/src/extract-hostname.ts b/vanilla/node_modules/tldts-core/src/extract-hostname.ts new file mode 100644 index 0000000..8211ff4 --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/extract-hostname.ts @@ -0,0 +1,170 @@ +/** + * @param url - URL we want to extract a hostname from. + * @param urlIsValidHostname - hint from caller; true if `url` is already a valid hostname. + */ +export default function extractHostname( + url: string, + urlIsValidHostname: boolean, +): string | null { + let start = 0; + let end: number = url.length; + let hasUpper = false; + + // If url is not already a valid hostname, then try to extract hostname. + if (!urlIsValidHostname) { + // Special handling of data URLs + if (url.startsWith('data:')) { + return null; + } + + // Trim leading spaces + while (start < url.length && url.charCodeAt(start) <= 32) { + start += 1; + } + + // Trim trailing spaces + while (end > start + 1 && url.charCodeAt(end - 1) <= 32) { + end -= 1; + } + + // Skip scheme. + if ( + url.charCodeAt(start) === 47 /* '/' */ && + url.charCodeAt(start + 1) === 47 /* '/' */ + ) { + start += 2; + } else { + const indexOfProtocol = url.indexOf(':/', start); + if (indexOfProtocol !== -1) { + // Implement fast-path for common protocols. We expect most protocols + // should be one of these 4 and thus we will not need to perform the + // more expansive validity check most of the time. + const protocolSize = indexOfProtocol - start; + const c0 = url.charCodeAt(start); + const c1 = url.charCodeAt(start + 1); + const c2 = url.charCodeAt(start + 2); + const c3 = url.charCodeAt(start + 3); + const c4 = url.charCodeAt(start + 4); + + if ( + protocolSize === 5 && + c0 === 104 /* 'h' */ && + c1 === 116 /* 't' */ && + c2 === 116 /* 't' */ && + c3 === 112 /* 'p' */ && + c4 === 115 /* 's' */ + ) { + // https + } else if ( + protocolSize === 4 && + c0 === 104 /* 'h' */ && + c1 === 116 /* 't' */ && + c2 === 116 /* 't' */ && + c3 === 112 /* 'p' */ + ) { + // http + } else if ( + protocolSize === 3 && + c0 === 119 /* 'w' */ && + c1 === 115 /* 's' */ && + c2 === 115 /* 's' */ + ) { + // wss + } else if ( + protocolSize === 2 && + c0 === 119 /* 'w' */ && + c1 === 115 /* 's' */ + ) { + // ws + } else { + // Check that scheme is valid + for (let i = start; i < indexOfProtocol; i += 1) { + const lowerCaseCode = url.charCodeAt(i) | 32; + if ( + !( + ( + (lowerCaseCode >= 97 && lowerCaseCode <= 122) || // [a, z] + (lowerCaseCode >= 48 && lowerCaseCode <= 57) || // [0, 9] + lowerCaseCode === 46 || // '.' + lowerCaseCode === 45 || // '-' + lowerCaseCode === 43 + ) // '+' + ) + ) { + return null; + } + } + } + + // Skip 0, 1 or more '/' after ':/' + start = indexOfProtocol + 2; + while (url.charCodeAt(start) === 47 /* '/' */) { + start += 1; + } + } + } + + // Detect first occurrence of '/', '?' or '#'. We also keep track of the + // last occurrence of '@', ']' or ':' to speed-up subsequent parsing of + // (respectively), identifier, ipv6 or port. + let indexOfIdentifier = -1; + let indexOfClosingBracket = -1; + let indexOfPort = -1; + for (let i = start; i < end; i += 1) { + const code: number = url.charCodeAt(i); + if ( + code === 35 || // '#' + code === 47 || // '/' + code === 63 // '?' + ) { + end = i; + break; + } else if (code === 64) { + // '@' + indexOfIdentifier = i; + } else if (code === 93) { + // ']' + indexOfClosingBracket = i; + } else if (code === 58) { + // ':' + indexOfPort = i; + } else if (code >= 65 && code <= 90) { + hasUpper = true; + } + } + + // Detect identifier: '@' + if ( + indexOfIdentifier !== -1 && + indexOfIdentifier > start && + indexOfIdentifier < end + ) { + start = indexOfIdentifier + 1; + } + + // Handle ipv6 addresses + if (url.charCodeAt(start) === 91 /* '[' */) { + if (indexOfClosingBracket !== -1) { + return url.slice(start + 1, indexOfClosingBracket).toLowerCase(); + } + return null; + } else if (indexOfPort !== -1 && indexOfPort > start && indexOfPort < end) { + // Detect port: ':' + end = indexOfPort; + } + } + + // Trim trailing dots + while (end > start + 1 && url.charCodeAt(end - 1) === 46 /* '.' */) { + end -= 1; + } + + const hostname: string = + start !== 0 || end !== url.length ? url.slice(start, end) : url; + + if (hasUpper) { + return hostname.toLowerCase(); + } + + return hostname; +} diff --git a/vanilla/node_modules/tldts-core/src/factory.ts b/vanilla/node_modules/tldts-core/src/factory.ts new file mode 100644 index 0000000..fe0880e --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/factory.ts @@ -0,0 +1,163 @@ +/** + * Implement a factory allowing to plug different implementations of suffix + * lookup (e.g.: using a trie or the packed hashes datastructures). This is used + * and exposed in `tldts.ts` and `tldts-experimental.ts` bundle entrypoints. + */ + +import getDomain from './domain'; +import getDomainWithoutSuffix from './domain-without-suffix'; +import extractHostname from './extract-hostname'; +import isIp from './is-ip'; +import isValidHostname from './is-valid'; +import { IPublicSuffix, ISuffixLookupOptions } from './lookup/interface'; +import { IOptions, setDefaults } from './options'; +import getSubdomain from './subdomain'; + +export interface IResult { + // `hostname` is either a registered name (including but not limited to a + // hostname), or an IP address. IPv4 addresses must be in dot-decimal + // notation, and IPv6 addresses must be enclosed in brackets ([]). This is + // directly extracted from the input URL. + hostname: string | null; + + // Is `hostname` an IP? (IPv4 or IPv6) + isIp: boolean | null; + + // `hostname` split between subdomain, domain and its public suffix (if any) + subdomain: string | null; + domain: string | null; + publicSuffix: string | null; + domainWithoutSuffix: string | null; + + // Specifies if `publicSuffix` comes from the ICANN or PRIVATE section of the list + isIcann: boolean | null; + isPrivate: boolean | null; +} + +export function getEmptyResult(): IResult { + return { + domain: null, + domainWithoutSuffix: null, + hostname: null, + isIcann: null, + isIp: null, + isPrivate: null, + publicSuffix: null, + subdomain: null, + }; +} + +export function resetResult(result: IResult): void { + result.domain = null; + result.domainWithoutSuffix = null; + result.hostname = null; + result.isIcann = null; + result.isIp = null; + result.isPrivate = null; + result.publicSuffix = null; + result.subdomain = null; +} + +// Flags representing steps in the `parse` function. They are used to implement +// an early stop mechanism (simulating some form of laziness) to avoid doing +// more work than necessary to perform a given action (e.g.: we don't need to +// extract the domain and subdomain if we are only interested in public suffix). +export const enum FLAG { + HOSTNAME, + IS_VALID, + PUBLIC_SUFFIX, + DOMAIN, + SUB_DOMAIN, + ALL, +} + +export function parseImpl( + url: string, + step: FLAG, + suffixLookup: ( + _1: string, + _2: ISuffixLookupOptions, + _3: IPublicSuffix, + ) => void, + partialOptions: Partial<IOptions>, + result: IResult, +): IResult { + const options: IOptions = /*@__INLINE__*/ setDefaults(partialOptions); + + // Very fast approximate check to make sure `url` is a string. This is needed + // because the library will not necessarily be used in a typed setup and + // values of arbitrary types might be given as argument. + if (typeof url !== 'string') { + return result; + } + + // Extract hostname from `url` only if needed. This can be made optional + // using `options.extractHostname`. This option will typically be used + // whenever we are sure the inputs to `parse` are already hostnames and not + // arbitrary URLs. + // + // `mixedInput` allows to specify if we expect a mix of URLs and hostnames + // as input. If only hostnames are expected then `extractHostname` can be + // set to `false` to speed-up parsing. If only URLs are expected then + // `mixedInputs` can be set to `false`. The `mixedInputs` is only a hint + // and will not change the behavior of the library. + if (!options.extractHostname) { + result.hostname = url; + } else if (options.mixedInputs) { + result.hostname = extractHostname(url, isValidHostname(url)); + } else { + result.hostname = extractHostname(url, false); + } + + // Check if `hostname` is a valid ip address + if (options.detectIp && result.hostname !== null) { + result.isIp = isIp(result.hostname); + if (result.isIp) { + return result; + } + } + + // Perform hostname validation if enabled. If hostname is not valid, no need to + // go further as there will be no valid domain or sub-domain. This validation + // is applied before any early returns to ensure consistent behavior across + // all API methods including getHostname(). + if ( + options.validateHostname && + options.extractHostname && + result.hostname !== null && + !isValidHostname(result.hostname) + ) { + result.hostname = null; + return result; + } + + if (step === FLAG.HOSTNAME || result.hostname === null) { + return result; + } + + // Extract public suffix + suffixLookup(result.hostname, options, result); + if (step === FLAG.PUBLIC_SUFFIX || result.publicSuffix === null) { + return result; + } + + // Extract domain + result.domain = getDomain(result.publicSuffix, result.hostname, options); + if (step === FLAG.DOMAIN || result.domain === null) { + return result; + } + + // Extract subdomain + result.subdomain = getSubdomain(result.hostname, result.domain); + if (step === FLAG.SUB_DOMAIN) { + return result; + } + + // Extract domain without suffix + result.domainWithoutSuffix = getDomainWithoutSuffix( + result.domain, + result.publicSuffix, + ); + + return result; +} diff --git a/vanilla/node_modules/tldts-core/src/is-ip.ts b/vanilla/node_modules/tldts-core/src/is-ip.ts new file mode 100644 index 0000000..33151c1 --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/is-ip.ts @@ -0,0 +1,87 @@ +/** + * Check if a hostname is an IP. You should be aware that this only works + * because `hostname` is already garanteed to be a valid hostname! + */ +function isProbablyIpv4(hostname: string): boolean { + // Cannot be shorted than 1.1.1.1 + if (hostname.length < 7) { + return false; + } + + // Cannot be longer than: 255.255.255.255 + if (hostname.length > 15) { + return false; + } + + let numberOfDots = 0; + + for (let i = 0; i < hostname.length; i += 1) { + const code = hostname.charCodeAt(i); + + if (code === 46 /* '.' */) { + numberOfDots += 1; + } else if (code < 48 /* '0' */ || code > 57 /* '9' */) { + return false; + } + } + + return ( + numberOfDots === 3 && + hostname.charCodeAt(0) !== 46 /* '.' */ && + hostname.charCodeAt(hostname.length - 1) !== 46 /* '.' */ + ); +} + +/** + * Similar to isProbablyIpv4. + */ +function isProbablyIpv6(hostname: string): boolean { + if (hostname.length < 3) { + return false; + } + + let start = hostname.startsWith('[') ? 1 : 0; + let end = hostname.length; + + if (hostname[end - 1] === ']') { + end -= 1; + } + + // We only consider the maximum size of a normal IPV6. Note that this will + // fail on so-called "IPv4 mapped IPv6 addresses" but this is a corner-case + // and a proper validation library should be used for these. + if (end - start > 39) { + return false; + } + + let hasColon = false; + + for (; start < end; start += 1) { + const code = hostname.charCodeAt(start); + + if (code === 58 /* ':' */) { + hasColon = true; + } else if ( + !( + ( + (code >= 48 && code <= 57) || // 0-9 + (code >= 97 && code <= 102) || // a-f + (code >= 65 && code <= 90) + ) // A-F + ) + ) { + return false; + } + } + + return hasColon; +} + +/** + * Check if `hostname` is *probably* a valid ip addr (either ipv6 or ipv4). + * This *will not* work on any string. We need `hostname` to be a valid + * hostname. + */ +export default function isIp(hostname: string): boolean { + return isProbablyIpv6(hostname) || isProbablyIpv4(hostname); +} diff --git a/vanilla/node_modules/tldts-core/src/is-valid.ts b/vanilla/node_modules/tldts-core/src/is-valid.ts new file mode 100644 index 0000000..03cc384 --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/is-valid.ts @@ -0,0 +1,79 @@ +/** + * Implements fast shallow verification of hostnames. This does not perform a + * struct check on the content of labels (classes of Unicode characters, etc.) + * but instead check that the structure is valid (number of labels, length of + * labels, etc.). + * + * If you need stricter validation, consider using an external library. + */ + +function isValidAscii(code: number): boolean { + return ( + (code >= 97 && code <= 122) || (code >= 48 && code <= 57) || code > 127 + ); +} + +/** + * Check if a hostname string is valid. It's usually a preliminary check before + * trying to use getDomain or anything else. + * + * Beware: it does not check if the TLD exists. + */ +export default function (hostname: string): boolean { + if (hostname.length > 255) { + return false; + } + + if (hostname.length === 0) { + return false; + } + + if ( + /*@__INLINE__*/ !isValidAscii(hostname.charCodeAt(0)) && + hostname.charCodeAt(0) !== 46 && // '.' (dot) + hostname.charCodeAt(0) !== 95 // '_' (underscore) + ) { + return false; + } + + // Validate hostname according to RFC + let lastDotIndex = -1; + let lastCharCode = -1; + const len = hostname.length; + + for (let i = 0; i < len; i += 1) { + const code = hostname.charCodeAt(i); + if (code === 46 /* '.' */) { + if ( + // Check that previous label is < 63 bytes long (64 = 63 + '.') + i - lastDotIndex > 64 || + // Check that previous character was not already a '.' + lastCharCode === 46 || + // Check that the previous label does not end with a '-' (dash) + lastCharCode === 45 || + // Check that the previous label does not end with a '_' (underscore) + lastCharCode === 95 + ) { + return false; + } + + lastDotIndex = i; + } else if ( + !(/*@__INLINE__*/ (isValidAscii(code) || code === 45 || code === 95)) + ) { + // Check if there is a forbidden character in the label + return false; + } + + lastCharCode = code; + } + + return ( + // Check that last label is shorter than 63 chars + len - lastDotIndex - 1 <= 63 && + // Check that the last character is an allowed trailing label character. + // Since we already checked that the char is a valid hostname character, + // we only need to check that it's different from '-'. + lastCharCode !== 45 + ); +} diff --git a/vanilla/node_modules/tldts-core/src/lookup/fast-path.ts b/vanilla/node_modules/tldts-core/src/lookup/fast-path.ts new file mode 100644 index 0000000..f80898f --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/lookup/fast-path.ts @@ -0,0 +1,80 @@ +import { IPublicSuffix, ISuffixLookupOptions } from './interface'; + +export default function ( + hostname: string, + options: ISuffixLookupOptions, + out: IPublicSuffix, +): boolean { + // Fast path for very popular suffixes; this allows to by-pass lookup + // completely as well as any extra allocation or string manipulation. + if (!options.allowPrivateDomains && hostname.length > 3) { + const last: number = hostname.length - 1; + const c3: number = hostname.charCodeAt(last); + const c2: number = hostname.charCodeAt(last - 1); + const c1: number = hostname.charCodeAt(last - 2); + const c0: number = hostname.charCodeAt(last - 3); + + if ( + c3 === 109 /* 'm' */ && + c2 === 111 /* 'o' */ && + c1 === 99 /* 'c' */ && + c0 === 46 /* '.' */ + ) { + out.isIcann = true; + out.isPrivate = false; + out.publicSuffix = 'com'; + return true; + } else if ( + c3 === 103 /* 'g' */ && + c2 === 114 /* 'r' */ && + c1 === 111 /* 'o' */ && + c0 === 46 /* '.' */ + ) { + out.isIcann = true; + out.isPrivate = false; + out.publicSuffix = 'org'; + return true; + } else if ( + c3 === 117 /* 'u' */ && + c2 === 100 /* 'd' */ && + c1 === 101 /* 'e' */ && + c0 === 46 /* '.' */ + ) { + out.isIcann = true; + out.isPrivate = false; + out.publicSuffix = 'edu'; + return true; + } else if ( + c3 === 118 /* 'v' */ && + c2 === 111 /* 'o' */ && + c1 === 103 /* 'g' */ && + c0 === 46 /* '.' */ + ) { + out.isIcann = true; + out.isPrivate = false; + out.publicSuffix = 'gov'; + return true; + } else if ( + c3 === 116 /* 't' */ && + c2 === 101 /* 'e' */ && + c1 === 110 /* 'n' */ && + c0 === 46 /* '.' */ + ) { + out.isIcann = true; + out.isPrivate = false; + out.publicSuffix = 'net'; + return true; + } else if ( + c3 === 101 /* 'e' */ && + c2 === 100 /* 'd' */ && + c1 === 46 /* '.' */ + ) { + out.isIcann = true; + out.isPrivate = false; + out.publicSuffix = 'de'; + return true; + } + } + + return false; +} diff --git a/vanilla/node_modules/tldts-core/src/lookup/interface.ts b/vanilla/node_modules/tldts-core/src/lookup/interface.ts new file mode 100644 index 0000000..495a642 --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/lookup/interface.ts @@ -0,0 +1,10 @@ +export interface IPublicSuffix { + isIcann: boolean | null; + isPrivate: boolean | null; + publicSuffix: string | null; +} + +export interface ISuffixLookupOptions { + allowIcannDomains: boolean; + allowPrivateDomains: boolean; +} diff --git a/vanilla/node_modules/tldts-core/src/options.ts b/vanilla/node_modules/tldts-core/src/options.ts new file mode 100644 index 0000000..520e21c --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/options.ts @@ -0,0 +1,39 @@ +export interface IOptions { + allowIcannDomains: boolean; + allowPrivateDomains: boolean; + detectIp: boolean; + extractHostname: boolean; + mixedInputs: boolean; + validHosts: string[] | null; + validateHostname: boolean; +} + +function setDefaultsImpl({ + allowIcannDomains = true, + allowPrivateDomains = false, + detectIp = true, + extractHostname = true, + mixedInputs = true, + validHosts = null, + validateHostname = true, +}: Partial<IOptions>): IOptions { + return { + allowIcannDomains, + allowPrivateDomains, + detectIp, + extractHostname, + mixedInputs, + validHosts, + validateHostname, + }; +} + +const DEFAULT_OPTIONS = /*@__INLINE__*/ setDefaultsImpl({}); + +export function setDefaults(options?: Partial<IOptions>): IOptions { + if (options === undefined) { + return DEFAULT_OPTIONS; + } + + return /*@__INLINE__*/ setDefaultsImpl(options); +} diff --git a/vanilla/node_modules/tldts-core/src/subdomain.ts b/vanilla/node_modules/tldts-core/src/subdomain.ts new file mode 100644 index 0000000..bbb9c97 --- /dev/null +++ b/vanilla/node_modules/tldts-core/src/subdomain.ts @@ -0,0 +1,11 @@ +/** + * Returns the subdomain of a hostname string + */ +export default function getSubdomain(hostname: string, domain: string): string { + // If `hostname` and `domain` are the same, then there is no sub-domain + if (domain.length === hostname.length) { + return ''; + } + + return hostname.slice(0, -domain.length - 1); +} |
