grafana/k6 · error

missing required argument 'testId'

Error message

missing required argument 'testId'

What it means

Thrown by the Page mapping's getByTestId method. Unlike other getBy* methods it takes a single mandatory argument (no options); the mapping checks it with k6common.IsNullish and parses it with parseStringOrRegex. Omitting it or passing null/undefined fails here.

Source

Thrown at internal/js/modules/k6/browser/browser/page_mapping.go:218

				return nil, errors.New("missing required argument 'placeholder'")
			}
			pplaceholder, popts := parseGetByBaseOptions(vu.Context(), placeholder, false, opts)

			ml := mapLocator(vu, p.GetByPlaceholder(pplaceholder, 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, p.GetByTitle(ptitle, popts))
			return rt.ToValue(ml).ToObject(rt), nil
		},
		"getByTestId": func(testID sobek.Value) (*sobek.Object, error) {
			if k6common.IsNullish(testID) {
				return nil, errors.New("missing required argument 'testId'")
			}
			ptestID := parseStringOrRegex(testID, false)

			ml := mapLocator(vu, p.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, p.GetByText(ptext, popts))
			return rt.ToValue(ml).ToObject(rt), nil
		},
		"goto": func(url string, opts sobek.Value) (*sobek.Promise, error) {
			gopts := common.NewFrameGotoOptions(
				p.Referrer(),

View on GitHub (pinned to 93accf6570)

Solutions

1. Pass the test id string or RegExp: page.getByTestId('submit-button')
2. Validate the id source: page.getByTestId(testId ?? 'submit-button'), or assert testId is truthy first
3. Note there is no options argument for getByTestId — the id must be the first and only argument

Example fix

// before
page.getByTestId();

// after
page.getByTestId('submit-button');

if (testId === undefined || testId === null) {
  throw new Error(`page.getByTestId: 'testId' is required, got ${testId}`);
}
const loc = page.getByTestId(testId);

function isTestId(v) {
  return typeof v === 'string' || v instanceof RegExp;
}

try {
  page.getByTestId(testId);
} catch (e) {
  if (!e.message.includes("missing required argument 'testId'")) throw e;
  throw new Error(`test id constant missing from constants module`);
}

When it happens

Trigger: page.getByTestId() with no arguments; page.getByTestId(undefined) when the test-id constant is misspelled or unset; calling it with (null, opts) assuming options exist.

Common situations: data-testid values maintained in a separate constants file with gaps; Playwright ports where getByTestId was given an empty string; refactors that pass the id via the wrong variable.

Related errors

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

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/e3f6c6990ad20586. Report an issue: GitHub.