@fly/cdn/lib/pipeline.js

Fly's TypeScript CDN

/**
 * A library for composing `fetch` generators into a single pipeline.
 *
 * @preferred
 * @module HTTP
 */
/**
 * Combine multiple fetches into a single function. Allows middleware type functionality
 *
 * Example:
 *
 * ```javascript
 * import { pipeline } from "@fly/fetch/pipeline"
 *
 * const addHeader = function(fetch){
 *   return function(req, init){
 *     if(typeof req === "string") req = new Request(req, init)
 *     req.headers.set("Superfly-Header", "shazam")
 *     return fetch(req, init)
 *   }
 * }
 *
 * const p = pipeline(fetch, addHeader)
 *
 * fly.http.respondWith(p)
 *
 * @param stages fetch generator functions that apply additional logic
 * @returns a combinedfunction that can be used anywhere that wants `fetch`
 */
export function pipeline(...stages) {
    /**
     * @param fetch the "origin" fetch function to call at the end of the pipeline
     */
    function pipelineFetch(fetch) {
        for (let i = stages.length - 1; i >= 0; i--) {
            const s = stages[i];
            const fn = typeof s === "function" ? s : s[0];
            const opts = s instanceof Array ? s[1] : [];
            fetch = fn(fetch, opts);
        }
        return Object.assign(fetch, { stages });
    }
    return Object.assign(pipelineFetch, { stages });
}
export default pipeline;
//# sourceMappingURL=data:application/json;base64,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