unexpected result type while getting document element: %T

Error message

unexpected result type while getting document element: %T

What it means

Internal invariant failure inside ElementHandle.ownerFrame(): the injected getDocumentElement evaluation returned a result, but it was not an *ElementHandle (e.g. null/undefined or a non-node remote object). This indicates the injected script could not resolve a document element from the given node - usually a protocol/version mismatch or a k6 bug rather than script misuse.

Source

Thrown at internal/js/modules/k6/browser/common/element_handle.go:1140

		(node, injected) => {
			return injected.getDocumentElement(node);
		}
	`
	opts := evalOptions{
		forceCallable: true,
		returnByValue: false,
	}
	res, err := h.evalWithScript(h.ctx, opts, fn)
	if err != nil {
		return nil, fmt.Errorf("getting document element: %w", err)
	}
	if res == nil {
		return nil, errors.New("getting document element: nil document")
	}

	documentHandle, ok := res.(*ElementHandle)
	if !ok {
		return nil, fmt.Errorf("unexpected result type while getting document element: %T", res)
	}
	defer func() {
		if err := documentHandle.Dispose(); err != nil {
			err = fmt.Errorf("disposing document element: %w", err)
			rerr = errors.Join(err, rerr)
		}
	}()

	if documentHandle.remoteObject.ObjectID == "" {
		return nil, err
	}

	var node *cdp.Node
	action := dom.DescribeNode().WithObjectID(documentHandle.remoteObject.ObjectID)
	if node, err = action.Do(cdp.WithExecutor(h.ctx, h.session)); err != nil {
		return nil, fmt.Errorf("getting node in frame: %w", err)
	}
	if node == nil || node.FrameID == "" {

View on GitHub (pinned to 93accf6570)

Solutions

Upgrade k6 to the latest release
Pin a Chromium version compatible with your k6 release
Work around by getting the frame via evaluate on contentWindow/frameElement
Report to k6 with the script and browser version

Example fix

// before
const f = await h.ownerFrame();
// after
await page.waitForLoadState('load');
const f = await h.ownerFrame();
if (!f) throw new Error('ownerFrame returned no frame');

Defensive patterns

Strategy: try-catch

Validate before calling

await page.waitForLoadState('load');
const el = await page.$('#in-frame');
const frame = el ? await el.ownerFrame() : null;
if (!frame) throw new Error('no frame resolved');

Try / catch

try {
  return await handle.ownerFrame();
} catch (e) {
  if (String(e).includes('unexpected result type')) {
    return null; // signal caller to fall back to evaluate-based frame detection
  }
  throw e;
}

Prevention

Keep k6 and Chromium versions aligned
Check the returned frame for null before using it
Report persistent occurrences to k6 maintainers

When it happens

Trigger: The evaluation returns a non-node value for getDocumentElement - seen with Chromium/CDP versions mismatched to the k6 release, handles on unusual nodes (e.g. already-collected documents), or k6 regressions. Rare in normal use.

Common situations: Canary/newer Chromium against an older k6; custom browser executables; calling ownerFrame on document-level handles.

Related errors

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/e63c8166b732fb60. Report an issue: GitHub.