Unhandled AbortError causes Unhandled Rejection

[zhzLuke96]

Description of the bug:

When an AbortController is triggered (e.g., via timeout or manual abort), the SDK throws an AbortError that cannot be caught using try...catch. This results in an Unhandled Rejection, forcing developers to handle it globally with process.on('unhandledRejection', ...).

Here is the error log:

[Unhandled rejection]
DOMException [AbortError]: This operation was aborted
    at new DOMException (node:internal/per_context/domexception:53:5)
    at AbortController.abort (node:internal/abort_controller:401:18)
    at EventTarget.<anonymous> (O:\work_space\github.com\@lenML\project1\node_modules\.pnpm\@google+generative-ai@0.21.0\node_modules\@google\generative-ai\dist\index.js:430:28)         
    at [nodejs.internal.kHybridDispatch] (node:internal/event_target:786:20)
    at EventTarget.dispatchEvent (node:internal/event_target:721:26)
    at abortSignal (node:internal/abort_controller:369:10)
    at AbortController.abort (node:internal/abort_controller:403:5)

Suspected problematic code:

generative-ai-js/src/requests/stream-reader.ts

Lines 78 to 128 in 2df2af0

	/**
	* Reads a raw stream from the fetch response and join incomplete
	* chunks, returning a new stream that provides a single complete
	* GenerateContentResponse in each iteration.
	*/
	export function getResponseStream<T>(
	inputStream: ReadableStream<string>,
	): ReadableStream<T> {
	const reader = inputStream.getReader();
	const stream = new ReadableStream<T>({
	start(controller) {
	let currentText = "";
	return pump();
	function pump(): Promise<(() => Promise<void>) | undefined> {
	return reader.read().then(({ value, done }) => {
	if (done) {
	if (currentText.trim()) {
	controller.error(
	new GoogleGenerativeAIError("Failed to parse stream"),
	);
	return;
	}
	controller.close();
	return;
	}
	currentText += value;
	let match = currentText.match(responseLineRE);
	let parsedResponse: T;
	while (match) {
	try {
	parsedResponse = JSON.parse(match[1]);
	} catch (e) {
	controller.error(
	new GoogleGenerativeAIError(
	`Error parsing JSON response: "${match[1]}"`,
	),
	);
	return;
	}
	controller.enqueue(parsedResponse);
	currentText = currentText.substring(match[0].length);
	match = currentText.match(responseLineRE);
	}
	return pump();
	});
	}
	},
	});
	return stream;
	}

Actual vs expected behavior:

• Actual:
  AbortError is not catchable by try...catch, causing unhandled promise rejections.

• Expected:
  AbortError should be catchable within try...catch in user code, without requiring global error handlers.

Any other information you'd like to share?

none

[arnab710]

Facing the same issue.
@zhzLuke96 did you find any solution?

[zhzLuke96]

@arnab710 In fact, I mentioned the solution above—using process.on('unhandledRejection', ...) to handle it (DOMException).

Specifically, the code would look something like this:

process.on("unhandledRejection", (err) => {
  if (err instanceof DOMException && err.name === "AbortError") {
    console.log(`[Abort] ${err.message}`);
    return;
  }

  console.error(`[Unhandled rejection]`);
  console.error(err);
});

This is one way to address it. However, it’s obvious that you won’t be able to identify where this error originated. You can’t tell whether it’s an error from your system or from generative-ai-js.

Of course, you can also choose to use a package patch and fix the stream-reader.ts code yourself. Simply put:

(I haven't actually used this method; it's just a guess that it might work, though there may be additional conditions to consider.)

stream-reader.ts 91 line

function pump(): Promise<(() => Promise<void>) | undefined> {
  return reader.read().then(({ value, done }) => {
    // ...
  }).catch(err => {
    // ... catch Abort Error here
  });
}

[danny-avila]

This is affecting me now, handling this at the global process level is not ideal. Would like to see some proper handling here at the SDK-level.

[KiGamji]

I don't really know how this error is occuring, but it often happens with Gemini completions in Russian language. If that internally is not related to the SDK itself, perhaps some of the SDK developers could report that to Google?

[danny-avila]

I updated the package for the fix, but catching the error is still necessary at the global level, though I am also able to catch it from the stream now.

[hkt74]

@danny-avila interesting, would you mind sharing the stack trace? maybe we need to catch the abort error beyond the stream reader.