toBeDisabled should match against web components / custom elements

[astorije]

• @testing-library/jest-dom version: 5.12.0
• @testing-library/react version: 11.2.7
• node version: 14.16.1
• yarn version: 1.22.5

Relevant code or config:

I used @cds/core (Clarity) which is a library of web components + @cds/react which is a bunch of React wrappers for said web components. Pretty much everything else is default config.

What you did:

This is the failing test:

  render(<CdsButton disabled>Foo</CdsButton>);
  expect(await screen.findByText("Foo")).toBeDisabled();

CdsButton under the hood renders a cds-button web component. It uses an async test because Clarity fills a bunch of props asynchronously, including disabled, aria-disabled, role, etc.

What happened:

Text version

FAIL  ./index.test.tsx
  ✕ should make sure the button is disabled (43 ms)

  ● should make sure the button is disabled

    expect(element).toBeDisabled()

    Received element is not disabled:
      <cds-button _nfg="" action="solid" aria-disabled="true" disabled="" loading-state="default" role="button" size="md" status="primary" tabindex="-1" />

      5 | test("should make sure the button is disabled", async () => {
      6 |   render(<CdsButton disabled>Foo</CdsButton>);
    > 7 |   expect(await screen.findByText("Foo")).toBeDisabled();
        |                                          ^
      8 | });
      9 |

      at index.test.tsx:7:42
      at step (index.test.tsx:33:23)
      at Object.next (index.test.tsx:14:53)
      at fulfilled (index.test.tsx:5:58)

Reproduction:

A minimal reproduction repo can be found at https://github.com/astorije/repro-web-component-tobedisabled.

Steps to reproduce:

• Clone the repo
• Run yarn install
• Run yarn test
• The error above will be thrown

Problem description:

I scratched my head for a bit as I initially thought Clarity was doing something unwanted, but as soon as I opened the toBeDisabled source, I realized that it filters again a hardcoded list).
Since no web components would ever be found in this list, toBeDisabled would not support them.

Suggested solution:

The doc says:

According to the specification, the following elements can be actually disabled: button, input, select, textarea, optgroup, option, fieldset.

However, that WHATWG spec lists an extra bullet point that is missing from that list:

a form-associated custom element that is disabled

So the hardcoded list needs to support web components aka custom elements.

According to MDN:

A DOMString representing the name you are giving to the element. Note that custom element names require a dash to be used in them (kebab-case); they can't be single words.

So my suggested solution is to add elements whose tags contain a hyphen to the list of elements that can actually be disabled.

[nickserv]

Are these still form elements though? As far as I remember, the disabled role is specifically for form elements, or at least our usage of it.

[astorije]

They can be! In the example described above, CdsButton is essentially indistinguishable from a styled button. I think the .toBeDisabled() assertion should honor the HTML spec in that regard.

We resorted to use .toHaveAttribute('disabled') and .not.toHaveAttribute('disabled') for now, but it's rather worrisome because if any of our developers misses this detail and accidentally uses .not.toBeDisabled() (which we initially enforced with https://github.com/testing-library/eslint-plugin-jest-dom/blob/master/docs/rules/prefer-enabled-disabled.md but we had to disable this rule from our ESLint config) instead of .not.toHaveAttribute('disabled'), that could give a false negative (aka .not.toBeDisabled() would not fail with, e.g., <CdsButton disabled />).

[tolgahanacar]

i had the same problem. I will create a new issue with details.

[tolgahanacar]

I solved the problem.
./app.js/
button data-testid="r_button" type="submit" disabled>r_sub /button
./app.test.js/
const rbutton = screen.getByTestId("r_button"); //get id
expect(rbutton).toBeDisabled();

[astorije]

This has been fixed by #368, thanks all!