Cypress POST handler template

cypress-modify-response.js

function handleRequestWith(makeResponse) {
  return (rawRequest) => {
    const { xhr } = rawRequest;
    Object.defineProperty(xhr.__proto__, 'response', { writable: true });
    xhr.response = JSON.stringify(makeResponse(rawRequest));
    return rawRequest;
  }
}

// sample usage:
cy.route({
  url: '/api/heroes',
  method: 'POST',
  response: '', // this will be overwritten by handleRequestWith

  onResponse: handleRequestWith(({ request }) => {
    // TODO(you): Put your handling logic here!
    const body = JSON.parse(request.body);

    // Return the response's body
    return { errorCode: 1337, message: "You hit the wrong button!" };
  })
});