Subsequently write to an intercepted SSE stream

[joergplewe]

Hi Community!

This is my first question to the forum, please bear with me.

I can establish an intercepted SSE stream as shown below.
What I'd like to do is write consecutive message to the stream kept open. But it seems that reply() closes the stream. I tried to get hold of the IncomingHTTPResponse object, but calling send() on it leads to the same result.

So is there a way to reply()/send() keeping the connection open?

Thanks for any help!

import { StaticResponse } from "cypress/types/net-stubbing";

const headers = {
  "Content-Type": "text/event-stream",
  Connection: "keep-alive",
  "Cache-Control": "no-cache"
};

function createSSEbody(dates: number[]) {
  let body = `data: Here I am!\n\n`;
  dates.forEach((d) => {
    body += `event: currentDate\ndata: ${d}\n\n`
  })
  return body;
}

describe("SSE testing", () => {
  it("displays sse date", () => {
    let body = createSSEbody([1000, 2000]);

    cy.intercept("GET", "/sseevents", (req) => {
      const resp: StaticResponse = {headers, statusCode: 200, body};
      req.on("response", (resp) => {
        console.log(resp);
      });
      req.reply(resp);
    }).as("sseconnection");
    
    cy.visit("localhost:4000");
    cy.get("#sse").should("have.text", "--");
    
    cy.wait("@sseconnection");
    cy.get("#sse").should("have.text", "01:00:02");    
  });
});

[bluepioupiou]

Hi, I ran into the same issue. No answer from community or Cypress team ?