fix(ui): Throw error if response is undefined in api client

[scttcper]

Ignore the error if caught. I'm not sure how this happens but its probably some sort of browser extension or browser error. fetch should always return an object Response

fixes JAVASCRIPT-31AQ - Cannot destructure property 'status' of 'r' as it is undefined.

[cursor]

Bug: Error Handling Bypass Causes Memory Leak

The new if (response === undefined) check throws an error that is then ignored by the catch block. This bypasses the normal error handling flow, preventing the errorHandler from being called (leading to silent failures for callers) and the completeHandler from being called (causing a memory leak as requests are not removed from activeRequests). Furthermore, the check does not account for response === null, which would still cause a TypeError during destructuring, resulting in inconsistent error handling.

static/app/api.tsx#L535-L659

sentry/static/app/api.tsx

Lines 535 to 659 in d1836a2

	async response => {
	if (response === undefined) {
	// For some reason, response is undefined? Throw to the error path.
	throw new Error('Response is undefined');
	}
	// The Response's body can only be resolved/used at most once.
	// So we clone the response so we can resolve the body content as text content.
	// Response objects need to be cloned before its body can be used.
	let responseJSON: any;
	let responseText: any;
	const {status, statusText} = response;
	let {ok} = response;
	let errorReason = 'Request not OK'; // the default error reason
	let twoHundredErrorReason: string | undefined;
	// Try to get text out of the response no matter the status
	try {
	responseText = await response.text();
	} catch (error) {
	twoHundredErrorReason = 'Failed awaiting response.text()';
	ok = false;
	if (error.name === 'AbortError') {
	errorReason = 'Request was aborted';
	} else {
	errorReason = error.toString();
	}
	}
	const responseContentType = response.headers.get('content-type');
	const isResponseJSON = responseContentType?.includes('json');
	const wasExpectingJson =
	requestHeaders.get('Accept') === Client.JSON_HEADERS.Accept;
	const isStatus3XX = status >= 300 && status < 400;
	if (status !== 204 && !isStatus3XX) {
	try {
	responseJSON = JSON.parse(responseText);
	} catch (error) {
	twoHundredErrorReason = 'Failed trying to parse responseText';
	if (error.name === 'AbortError') {
	ok = false;
	errorReason = 'Request was aborted';
	} else if (isResponseJSON && error instanceof SyntaxError) {
	// If the MIME type is `application/json` but decoding failed,
	// this should be an error.
	ok = false;
	errorReason = 'JSON parse error';
	} else if (
	// Empty responses from POST 201 requests are valid
	responseText?.length > 0 &&
	wasExpectingJson &&
	error instanceof SyntaxError
	) {
	// Was expecting json but was returned something else. Possibly HTML.
	// Ideally this would not be a 200, but we should reject the promise
	ok = false;
	errorReason = 'JSON parse error. Possibly returned HTML';
	}
	}
	}
	const responseMeta: ResponseMeta = {
	status,
	statusText,
	responseJSON,
	responseText,
	getResponseHeader: (header: string) => response.headers.get(header),
	};
	// Respect the response content-type header
	const responseData = isResponseJSON ? responseJSON : responseText;
	if (ok) {
	successHandler(responseMeta, statusText, responseData);
	} else {
	// There's no reason we should be here with a 200 response, but we get
	// tons of events from this codepath with a 200 status nonetheless.
	// Until we know why, let's do what is essentially some very fancy print debugging.
	if (status === 200 && responseText) {
	const parameterizedPath = sanitizePath(path);
	const message = '200 treated as error';
	Sentry.withScope(scope => {
	scope.setTags({endpoint: `${method} ${parameterizedPath}`, errorReason});
	scope.setExtras({
	twoHundredErrorReason,
	responseJSON,
	responseText,
	responseContentType,
	errorReason,
	});
	// Make sure all of these errors group, so we don't produce a bunch of noise
	scope.setFingerprint([message]);
	Sentry.captureException(
	new Error(`${message}: ${method} ${parameterizedPath}`)
	);
	});
	}
	const shouldSkipErrorHandler = globalErrorHandlers
	.map(handler => handler(responseMeta, options))
	.some(Boolean);
	if (!shouldSkipErrorHandler) {
	errorHandler(responseMeta, statusText, errorReason);
	}
	}
	completeHandler(responseMeta, statusText);
	},
	() => {
	// Ignore failed fetch calls or errors in the fetch request itself (e.g. cancelled requests)
	// Not related to errors in responses
	}
	)
	.catch(error => {
	// eslint-disable-next-line no-console
	console.error(error);
	if (error?.name !== 'AbortError' && error?.message !== 'Response is undefined') {
	Sentry.captureException(error);
	}

Fix in Cursor

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