grafana/k6 · error

missing required argument 'title'

Error message

missing required argument 'title'

What it means

FrameLocator.getByTitle(title) in the k6 browser module requires a non-nullish first argument; the mapping layer rejects absent, null, or undefined values up front. The title (string or RegExp) matches elements' title attribute and is the method's only selector input. This mirrors Playwright's mandatory-argument contract.

Source

Thrown at internal/js/modules/k6/browser/browser/frame_locator_mapping.go:71

				return nil, errors.New("missing required argument 'testId'")
			}
			ptestID := parseStringOrRegex(testID, false)

			ml := mapLocator(vu, fl.GetByTestID(ptestID))
			return rt.ToValue(ml).ToObject(rt), nil
		},
		"getByText": func(text sobek.Value, opts sobek.Value) (*sobek.Object, error) {
			if k6common.IsNullish(text) {
				return nil, errors.New("missing required argument 'text'")
			}
			ptext, popts := parseGetByBaseOptions(vu.Context(), text, true, opts)

			ml := mapLocator(vu, fl.GetByText(ptext, popts))
			return rt.ToValue(ml).ToObject(rt), nil
		},
		"getByTitle": func(title sobek.Value, opts sobek.Value) (*sobek.Object, error) {
			if k6common.IsNullish(title) {
				return nil, errors.New("missing required argument 'title'")
			}
			ptitle, popts := parseGetByBaseOptions(vu.Context(), title, false, opts)

			ml := mapLocator(vu, fl.GetByTitle(ptitle, popts))
			return rt.ToValue(ml).ToObject(rt), nil
		},
		"locator": func(selector string, opts sobek.Value) mapping {
			return mapLocator(vu, fl.Locator(selector, parseLocatorOptions(rt, opts)))
		},
		"frameLocator": func(selector string) *sobek.Object {
			mfl := mapFrameLocator(vu, fl.FrameLocator(selector))
			return rt.ToValue(mfl).ToObject(rt)
		},
	}
}

View on GitHub (pinned to 93accf6570)

Solutions

1. Pass the title string or RegExp: frameLocator.getByTitle('Close dialog')
2. Validate or default the data-sourced title before the call
3. Fix the property name or export supplying the value
4. Use a RegExp for dynamic titles, e.g. getByTitle(/^Error \(\d+\)$/)

Example fix

// before
const closeBtn = page.frameLocator('#modal-frame').getByTitle(tooltipVar); // tooltipVar is undefined

// after
const tooltipVar = 'Close this dialog';
const closeBtn = page.frameLocator('#modal-frame').getByTitle(tooltipVar);

const title = tips.close;
if (!isTextSelector(title)) throw new Error('tips.close is required for getByTitle');
frameLocator.getByTitle(title);

function isTextSelector(v) {
  return (typeof v === 'string' && v.length > 0) || v instanceof RegExp;
}

try {
  loc = frameLocator.getByTitle(maybeTitle);
} catch (e) {
  if (/missing required argument 'title'/.test(String(e.message))) {
    throw new Error(`title missing; check tooltip data for key='${key}'`);
  }
  throw e;
}

When it happens

Trigger: Calling page.frameLocator('iframe').getByTitle() with no argument, passing null/undefined, or forwarding a tooltip-text variable that resolved to undefined from test data.

Common situations: Tooltip/aria-title assertions where the expected string lives in external data, refactors renaming title variables, or helper functions with optional parameters passed through directly.

Related errors

• missing required argument 'altText'
• missing required argument 'label'
• missing required argument 'placeholder'
• missing required argument 'role'
• missing required argument 'testId'

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/261a8eb571bfdb2b. Report an issue: GitHub.