microsoft/playwright · error · Error

Empty "by" locator. Start with one of by.role(), by.text(),

Error message

Empty "by" locator. Start with one of by.role(), by.text(), by.testId() and friends.

What it means

Error "Empty "by" locator. Start with one of by.role(), by.text(), by.testId() and friends." thrown in microsoft/playwright.

Source

Thrown at packages/isomorphic/by.ts:143

    return this._append(name => getByTestIdSelector(name, testId));
  }

  text(text: string | RegExp, options?: { exact?: boolean }): By {
    return this._append(() => getByTextSelector(text, options));
  }

  title(text: string | RegExp, options?: { exact?: boolean }): By {
    return this._append(() => getByTitleSelector(text, options));
  }
}

export const by: By = new ByImpl(() => '');

// The test id attribute is only known once the By is bound to a page, hence the deferred build.
export function resolveBy(by: By, testIdAttributeName: string): string {
  const selector = (by as ByImpl)._build(testIdAttributeName);
  if (!selector)
    throw new Error(`Empty "by" locator. Start with one of by.role(), by.text(), by.testId() and friends.`);
  return selector;
}

View on GitHub (pinned to c8fc3bf8d3)

When it happens

Trigger: Thrown at packages/isomorphic/by.ts:143 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/playwright@c8fc3bf8d3 (2026-08-12). Data as JSON: /api/errors/657098d242dcce0b. Report an issue: GitHub.