microsoft/playwright · error · Error

Passing a function is not supported as an argument here

Error message

Passing a function is not supported as an argument here

What it means

Error "Passing a function is not supported as an argument here" thrown in microsoft/playwright.

Source

Thrown at packages/playwright-core/src/client/jsHandle.ts:121

  };
  const value = serializeValue(arg, value => {
    if (value instanceof JSHandle)
      return { h: pushHandle(value._channel) };
    if (typeof value === 'function' && registerCallback)
      return { fn: registerCallback(value as Function) };
    return { fallThrough: value };
  });
  return { value, handles };
}

export type EvaluateOptions = { exposeFunctions?: boolean };

export async function serializeArgumentWithCallbacks(owner: ChannelOwner<any>, page: Page | undefined, arg: any): Promise<channels.SerializedArgument> {
  return await owner._wrapApiCall(async () => {
    const exposePromises: Promise<void>[] = [];
    const serialized = serializeArgument(arg, callback => {
      if (!page)
        throw new Error('Passing a function is not supported as an argument here');
      const name = kFunctionBindingPrefix + createGuid();
      exposePromises.push(page._exposeEvaluateCallback(name, callback));
      return name;
    });
    await Promise.all(exposePromises);
    return serialized;
  }, { internal: true });
}

export function parseResult(value: channels.SerializedValue): any {
  return parseSerializedValue(value, undefined);
}

export function assertMaxArguments(count: number, max: number): asserts count {
  if (count > max)
    throw new Error('Too many arguments. If you need to pass more than 1 argument to the function wrap them in an object.');
}

View on GitHub (pinned to c8fc3bf8d3)

When it happens

Trigger: Thrown at packages/playwright-core/src/client/jsHandle.ts:121 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/15a64ebf987d0b00. Report an issue: GitHub.