Method fetch

js/http_fetcher.js:278–349

* Performs the HTTP fetch and emits appropriate events * @fires HTTPFetcher#response * @fires HTTPFetcher#error

()

	 * @fires HTTPFetcher#error
	 */
	async fetch () {
		this.clearTimer();

		let nextDelay = this.reloadInterval;
		const controller = new AbortController();
		const timeoutId = setTimeout(() => controller.abort(), this.timeout);

		try {
			const requestOptions = this.getRequestOptions();
			// Use undici.fetch when a custom dispatcher is present (e.g. selfSignedCert),
			// because Node's global fetch and npm undici@8 Agents are incompatible.
			// For regular requests, use globalThis.fetch so MSW and other interceptors work.
			const fetchFn = requestOptions.dispatcher ? undiciFetch : globalThis.fetch;
			const response = await fetchFn(this.url, {
				...requestOptions,
				signal: controller.signal
			});

			const isSuccessfulResponse = response.ok || response.status === 304;

			if (isSuccessfulResponse) {
				// Reset error counts on success
				this.serverErrorCount = 0;
				this.networkErrorCount = 0;

				/**
				 * Response event - fired when fetch succeeds (including 304)
				 * @event HTTPFetcher#response
				 * @type {Response}
				 */
				this.emit("response", response);
			} else {
				const { delay, errorInfo } = this.#getDelayForResponse(response);
				nextDelay = delay;
				this.emit("error", errorInfo);
			}
		} catch (error) {
			const isTimeout = error.name === "AbortError";
			const message = isTimeout ? `Request timeout after ${this.timeout}ms` : `Network error: ${error.message}`;

			this.networkErrorCount = Math.min(this.networkErrorCount + 1, this.maxRetries);
			const exhausted = this.networkErrorCount >= this.maxRetries;

			if (exhausted) {
				nextDelay = this.reloadInterval;
				Log.error(`${this.logContext}${this.#shortenUrl()} - ${message} Max retries reached, retrying at configured interval (${Math.round(nextDelay / 1000)}s).`);
			} else {
				nextDelay = HTTPFetcher.calculateBackoffDelay(this.networkErrorCount, {
					maxDelay: this.reloadInterval
				});
				const retryMsg = `${this.logContext}${this.#shortenUrl()} - ${message} Retry #${this.networkErrorCount} in ${Math.round(nextDelay / 1000)}s.`;
				if (this.networkErrorCount <= 2) {
					Log.warn(retryMsg);
				} else {
					Log.error(retryMsg);
				}
			}