Getting TypeError: unusable when trying to read a binary request's body inside a test

[canrozanes]

For some reason, I'm able to read the binary msw response body but not the request body.

I have few response read & write helpers

export async function readProtoRequest(request: Request) {
  const arrayBuffer = await request.clone().arrayBuffer();
  return Decoder.decode(new Uint8Array(arrayBuffer));
}

export async function readProtoResponse(response: Response) {
  const arrayBuffer = await response.clone().arrayBuffer();
  return Decoder.decode(new Uint8Array(arrayBuffer));
}

And my test

describe('some module', () => {
  let handledRequestsAndResponses = [];
  beforeEach(() => {
    mswServer.events.on(
      'response:mocked',
      ({ request, response, requestId }) => {
        handledRequestsAndResponses.push({ request, response, requestId });
      },
    );
  });
  const { handledRequestsAndResponses } = setupMswTests();
    test('triggers the correct request', async () => {
      await renderComponent()
      const saveButton = screen.getByRole('button', { name: 'Save Item' });
      await clickElement(saveButton);

      await waitFor(() => expect(saveButton).not.toHaveAttribute('is-loading'));

      const reqAndRes = handledRequestsAndResponses.find((reqAndRes) =>
        reqAndRes.request.url.includes('UpsertObject'),
      );

      console.log(await readProtoResponse(reqAndRes.response) // this works
      console.log(await readProtoRequest(reqAndRes.request) // this throws and error TypeError: unusable
    });
  });
});

TypeError: unusable
 ❯ readProtoRequest src/pages/items/library/upsert.test.tsx:254:37
    252|
    253| export async function readProtoRequest(request: Request) {
    254|   const arrayBuffer = await request.clone().arrayBuffer();
       |                                     ^
    255|
    256|   return Decoder.decode(new Uint8Array(arrayBuffer));

I saw this issue but updating to latest msw didn't fix it for me.

Is this a bug? I'm happy to open an issue if we think so.

[kettanaito]

Hi. The error likely means that you are reading the request body elsewhere during this handling without calling .clone(). Take a look if that's the case. If not, share a minimal reproduction so I could take a look. Thanks.