commands.js

function zip(lists) {
    return lists[0].map((_, i) => lists.map(array => array[i]));
}

function addCommands() {
  Cypress.Commands.add("resetWsMessages", () => {
      cy.request("DELETE", "http://localhost:3000/__cypress/messages");
  });

  Cypress.Commands.add("overrideWsOptions", options => {
      cy.request({
        method: "POST",
        url: "http://localhost:3000/__cypress/options",
        body: options,
      );
  });

  Cypress.Commands.add("expectWsMessages", (expected, options) => {
      const sleepTime = 250;
      const maxInvocations = ((options && options.timeout) || 2500) / sleepTime;

      function waitForMessages(invocation) {
          if (invocation > 10) {
              throw "Giving up waiting after 2.5s";
          }

          return cy.wait(sleepTime).then(() => {
              return cy.request("GET", 'http://localhost:3000/__cypress/messages')
                .its("body")
                .then(body => {
                    if (body.length < expected.length) {
                        return waitForMessages(invocation + 1);
                    }
                    else {
                        return body;
                    }
                });
          });
      }

      waitForMessages(0).then(actual => {
          cy.expect(actual.map(JSON.stringify)).to.include.members(expected.map(JSON.stringify));
      });
  });
}

module.exports = {
    addCommands,
};