/* Copyright 2019 Google LLC Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at https://opensource.org/licenses/MIT. */ import { canConstructResponseFromBodyStream } from './_private/canConstructResponseFromBodyStream.js'; import { WorkboxError } from './_private/WorkboxError.js'; import './_version.js'; /** * Allows developers to copy a response and modify its `headers`, `status`, * or `statusText` values (the values settable via a * [`ResponseInit`]{@link https://developer.mozilla.org/en-US/docs/Web/API/Response/Response#Syntax} * object in the constructor). * To modify these values, pass a function as the second argument. That * function will be invoked with a single object with the response properties * `{headers, status, statusText}`. The return value of this function will * be used as the `ResponseInit` for the new `Response`. To change the values * either modify the passed parameter(s) and return it, or return a totally * new object. * * This method is intentionally limited to same-origin responses, regardless of * whether CORS was used or not. * * @param {Response} response * @param {Function} modifier * @memberof workbox-core */ async function copyResponse(response, modifier) { let origin = null; // If response.url isn't set, assume it's cross-origin and keep origin null. if (response.url) { const responseURL = new URL(response.url); origin = responseURL.origin; } if (origin !== self.location.origin) { throw new WorkboxError('cross-origin-copy-response', { origin }); } const clonedResponse = response.clone(); // Create a fresh `ResponseInit` object by cloning the headers. const responseInit = { headers: new Headers(clonedResponse.headers), status: clonedResponse.status, statusText: clonedResponse.statusText, }; // Apply any user modifications. const modifiedResponseInit = modifier ? modifier(responseInit) : responseInit; // Create the new response from the body stream and `ResponseInit` // modifications. Note: not all browsers support the Response.body stream, // so fall back to reading the entire body into memory as a blob. const body = canConstructResponseFromBodyStream() ? clonedResponse.body : await clonedResponse.blob(); return new Response(body, modifiedResponseInit); } export { copyResponse };