Question: How do I mock an empty response?

Today is the first time I am using this library. I am trying to mock an API for unit-testing using React Testing Library with CRA in TypeScript. The API takes a PUT request and gives 204 success response with empty payload in the response. So response looks like this in Chrome:

I tried this:

rest.put('/api', (req: MockedRequest<DefaultRequestBodyType, RequestParams>, res: ResponseComposition<any>, ctx: RestContext) => res(ctx.status(204))),

but got this error:

TypeError: Cannot read property 'length' of null
at node_modules/node-request-interceptor/src/interceptors/XMLHttpRequest/XMLHttpRequestOverride.ts:280:37

Apologies if its a silly question to ask. Also apologies if I am posting in wrong format, I have never posted a query before.

[indiansage]

It worked, thanks for the quick resolution @kettanaito!

[kettanaito]

@marcosvega91, I’ve addressed that in the fix pull request. There are two separate statements:

• Response JSON body parsing must be graceful. XHR doesn’t raise an exception if the response body is an invalid JSON. We should retain that behavior.
• The “progress” event, where we reference this.response.length was implemented incorrectly. Instead, I suggest we convert any existing mocked response body (basically, a string) into a Buffer and access its length.

Yes I think that before that request there is a not handled request that has a responseType equal to json that will persist in the next request

This would be truly peculiar, as responseType value is received from the request client, we are not setting it anywhere in the XMLHttpRequestOverride class.