react-testing-library queryByTestId returning NULL

Question

I'm making the switch from using enzyme to react-testing-library for testing my components.

I have a simple component CustomModal which acts much like a wrapper around the Modal from reactstrap. I am trying to test that my CustomModal includes the child elements that it ought to.

Taking my cues from this article and this article, I am adding data-testid attributes to my children, and then I am using getByTestId and queryByTestId. But, for some reason, my queries are not finding the child nodes that, as far as I can tell, are there.

Is there something I am doing wrong in my test setup, or am I misunderstanding how react-testing-library should be used?

The basic code, along with the test (which is failing), can be found in this CodeSandbox:

My basic CustomModal component looks like this:

/*
 * src/components/CustomModal/index.js
 */

import React from "react";
import { Button, Modal, ModalHeader, ModalBody, ModalFooter } from "reactstrap";

const getSanitizedModalProps = props => {
  let modalProps = { ...props };
  delete modalProps.onConfirm;
  delete modalProps.onCancel;
  delete modalProps.headerText;
  delete modalProps.children;
  modalProps.isOpen = modalProps.isOpen === true;
  return modalProps;
};

export default props => {
  return (
    <Modal data-testid="modal" {...getSanitizedModalProps(props)}>
      <ModalHeader data-testid="modal-header">{props.headerText}</ModalHeader>
      <ModalBody data-testid="modal-body">{props.children}</ModalBody>
      <ModalFooter data-testid="modal-footer">
        <Button data-testid="confirm-button" onClick={props.onConfirm}>
          Confirm
        </Button>
        <Button data-testid="cancel-button" onClick={props.onCancel}>
          Cancel
        </Button>
      </ModalFooter>
    </Modal>
  );
};

My test file looks like this:

/*
 * src/components/CustomModal/CustomModal.test.js
 */

import React from "react";
import { render } from "react-testing-library";
import CustomModal from "./index";

const TEST_IDS = {
  modal: "modal",
  header: "modal-header",
  body: "modal-body",
  footer: "modal-footer",
  cancel: "cancel-button",
  confirm: "confirm-button"
};

describe("<Modal />", () => {
  const headerText = "hello world";
  it("renders all of the children", () => {
    const { queryByTestId } = render(<CustomModal headerText={headerText} />);

    // The following assertions all fail
    expect(queryByTestId(TEST_IDS.modal)).toBeTruthy(); 
    expect(queryByTestId(TEST_IDS.header)).toBeTruthy();
    expect(queryByTestId(TEST_IDS.body)).toBeTruthy();
    expect(queryByTestId(TEST_IDS.footer)).toBeTruthy();
    expect(queryByTestId(TEST_IDS.cancel)).toBeTruthy();
    expect(queryByTestId(TEST_IDS.confirm)).toBeTruthy();
  });
});

Answer 1

Your modal is closed, you need to pass isOpen to it:

render(<CustomModal headerText={headerText} isOpen />);