How can I stub a server side response via cypress?

I'm running a react project that returns html in the response of the network call (server side rendering). I wanted to stub the html response for testing however I'm not sure how that would work.

Here's what I've tried:

it("Example test", () => {
cy.intercept('GET', '/some-network-call', {
  statusCode: 200,
  body: html
}).as('mockedResponse');
cy.visit("http://localhost:3000");
cy.wait('@mockedResponse').then(() => {
  cy.screenshot("Test Screenshot");
 });
});

The intercept indeed does its job, however, the output just breaks the rendered app.
The Cypress docs mention you can stub things like the header, body, statuscode, etc. Is there a good way to simulate server side calls that return html responses?

If the intercept is working (cy.wait('@mockedResponse') is not timing out), then strictly speaking it's not server-side rendering - at least not that particular call.

But semantics aside, it looks like body: html is not correct, whatever html is.

To find out exactly what the server is serving up, temporarily remove the mock response and capture the server's response via cy.wait('@mockedResponse'), then modify your stub accordingly.

it("Example test", () => {
cy.intercept('GET', '/some-network-call').as('mockedResponse');
cy.visit("http://localhost:3000");
cy.wait('@mockedResponse').then(interception => {
  console.log(interception.response)  // take a look at what the app sees 
                                      // from the live server, base your mock on that
});