Parse Link Header

## Source Code File: `src/utils/functions/parse-link-header.ts` ````typescript type LinkInfo = { url: string; rel: string; [key: string]: string; }; type ParsedLinks = { [rel: string]: LinkInfo; }; /** * Parses HTTP Link header according to RFC 5988 * @param linkHeader - The Link header string to parse * @returns Parsed links object with rel as key and link info as value * * @example * ```ts * const linkHeader = '; rel="next"'; * const parsed = parseLinkHeader(linkHeader); * // Returns: { next: { url: 'https://api.github.com/repos?page=2', rel: 'next' } } * ``` */ export function parseLinkHeader(linkHeader: string): ParsedLinks { if (!linkHeader || typeof linkHeader !== 'string') { return {}; } const result: ParsedLinks = {}; // Split by comma to get individual link entries const linkEntries = linkHeader.split(','); for (const entry of linkEntries) { const trimmedEntry = entry.trim(); if (!trimmedEntry) continue; // Parse URL (between < and >) const urlMatch = trimmedEntry.match(/^<([^>]+)>/); if (!urlMatch) continue; const url = urlMatch[1]; const parametersString = trimmedEntry.substring(urlMatch[0].length); // Parse parameters after the URL const linkInfo: LinkInfo = { url, rel: '' }; // Extract URL parameters from the URL itself try { const urlObj = new URL(url); urlObj.searchParams.forEach((value, key) => { linkInfo[key] = value; }); } catch { // If URL parsing fails, continue without URL parameters } // Parse link parameters (after the URL, separated by semicolons) const paramMatches = parametersString.matchAll( /;\s*([^=]+)=(?:"([^"]*)"|([^;,\s]+))/g ); for (const match of paramMatches) { const key = match[1].trim(); const value = match[2] || match[3] || ''; linkInfo[key] = value; } // Use rel as the key in the result object if (linkInfo.rel) { result[linkInfo.rel] = linkInfo; } } return result; } ```` ## Description The `parseLinkHeader` function parses HTTP Link headers commonly used in REST APIs for pagination. It: - Extracts URLs and their relationship types (rel) - Parses URL query parameters - Parses link metadata parameters - Returns an object keyed by relationship type (e.g., "next", "prev", "first", "last") This is particularly useful for handling paginated API responses from services like GitHub, GitLab, and other REST APIs that follow RFC 5988.