Snippet how to mock GraphQL request in cypress

cypress_mockGraphQL.js

// --------------------------------------
// Mock GraphQL requests with stubs.
// Inspiration: https://github.com/cypress-io/cypress-documentation/issues/122
// --------------------------------------
Cypress.Commands.add('visitWithMockedGraphQL', (page, stubs) => {
  cy.visit(page, {
    onBeforeLoad: win => {
      cy.stub(win, 'fetch', handleFetch(stubs));
    },
  });
});

function handleFetch(stubs) {
  return (...args) => {
    const [url, request] = args;
    const postBody = JSON.parse(request.body);

    if (url.includes('graphql.kiwi.com')) {
      const stub = stubs.find(
        stub => postBody.operationName === stub.operation, // eslint-disable-line no-shadow
      );

      if (stub) {
        return Promise.resolve({
          ok: true,
          json: () => Promise.resolve(stub.response),
        });
      }
    }

    // either no GraphQL request or operation that wasn't stubbed
    return fetch(...args);
  };
}