zone.js/fesm2015/zone-patch-fetch.js

Zones for JavaScript

'use strict';
/**
 * @license Angular v<unknown>
 * (c) 2010-2024 Google LLC. https://angular.io/
 * License: MIT
 */
/**
 * @fileoverview
 * @suppress {missingRequire}
 */
function patchFetch(Zone) {
    Zone.__load_patch('fetch', (global, Zone, api) => {
        let fetch = global['fetch'];
        if (typeof fetch !== 'function') {
            return;
        }
        const originalFetch = global[api.symbol('fetch')];
        if (originalFetch) {
            // restore unpatched fetch first
            fetch = originalFetch;
        }
        const ZoneAwarePromise = global.Promise;
        const symbolThenPatched = api.symbol('thenPatched');
        const fetchTaskScheduling = api.symbol('fetchTaskScheduling');
        const OriginalResponse = global.Response;
        const placeholder = function () { };
        const createFetchTask = (source, data, originalImpl, self, args, ac) => new Promise((resolve, reject) => {
            const task = Zone.current.scheduleMacroTask(source, placeholder, data, () => {
                // The promise object returned by the original implementation passed into the
                // function. This might be a `fetch` promise, `Response.prototype.json` promise,
                // etc.
                let implPromise;
                let zone = Zone.current;
                try {
                    zone[fetchTaskScheduling] = true;
                    implPromise = originalImpl.apply(self, args);
                }
                catch (error) {
                    reject(error);
                    return;
                }
                finally {
                    zone[fetchTaskScheduling] = false;
                }
                if (!(implPromise instanceof ZoneAwarePromise)) {
                    let ctor = implPromise.constructor;
                    if (!ctor[symbolThenPatched]) {
                        api.patchThen(ctor);
                    }
                }
                implPromise.then((resource) => {
                    if (task.state !== 'notScheduled') {
                        task.invoke();
                    }
                    resolve(resource);
                }, (error) => {
                    if (task.state !== 'notScheduled') {
                        task.invoke();
                    }
                    reject(error);
                });
            }, () => {
                ac?.abort();
            });
        });
        global['fetch'] = function () {
            const args = Array.prototype.slice.call(arguments);
            const options = args.length > 1 ? args[1] : {};
            const signal = options?.signal;
            const ac = new AbortController();
            const fetchSignal = ac.signal;
            options.signal = fetchSignal;
            args[1] = options;
            if (signal) {
                const nativeAddEventListener = signal[Zone.__symbol__('addEventListener')] ||
                    signal.addEventListener;
                nativeAddEventListener.call(signal, 'abort', function () {
                    ac.abort();
                }, { once: true });
            }
            return createFetchTask('fetch', { fetchArgs: args }, fetch, this, args, ac);
        };
        if (OriginalResponse?.prototype) {
            // https://fetch.spec.whatwg.org/#body-mixin
            ['arrayBuffer', 'blob', 'formData', 'json', 'text']
                // Safely check whether the method exists on the `Response` prototype before patching.
                .filter((method) => typeof OriginalResponse.prototype[method] === 'function')
                .forEach((method) => {
                api.patchMethod(OriginalResponse.prototype, method, (delegate) => (self, args) => createFetchTask(`Response.${method}`, undefined, delegate, self, args, undefined));
            });
        }
    });
}

patchFetch(Zone);