Usage of --host argument in the npm script throws error, How do we resolve the issue?

[nithincspnr]

Hey!

As per the instruction, if we put --host argument in the npm run dev script it should expose the IP in the network, but I am getting an error in console.

Instruction in the console

What Error I am getting

Questions

1. How do resolve this error?
2. I feel that instruction in the first place itself is misleading. could we please improve the instruction/fix the issue?

[CoderDeltaLAN]

Context

• Remix 2.17
• Cypress E2E tests fail when using a single fetch call
• Works in browser, breaks in Cypress runner

Why
Cypress runs in its own browser context and intercepts network. Common pitfalls:

• Server-side fetch not mocked → Cypress waits for a response that never comes
• Requests go to localhost but app/test server mismatch (port or protocol)
• Cypress default chromeWebSecurity blocks cross-origin fetch
• Data loaded via Remix loader might be cached, but Cypress reload breaks it

Fix (minimum viable)

1. Ensure same origin in tests
   In cypress.config.js:

   export default defineConfig({
     e2e: {
       baseUrl: "http://localhost:3000",
       chromeWebSecurity: false, // allow cross-origin fetch if needed
     },
   });

2. Mock fetch in Cypress if you want deterministic results

   // cypress/e2e/example.cy.js
   it("stubs API", () => {
     cy.intercept("GET", "/api/data", { fixture: "data.json" }).as("data")
     cy.visit("/")
     cy.wait("@data")
     cy.contains("Hello world")
   })

3. Check Remix loader usage

   • If your loader calls await fetch("http://localhost:3000/api/..."), it may hang under Cypress because that URL is not accessible.
   • Prefer relative URLs: await fetch("/api/...").

4. Add test server health check
   Before Cypress runs, ensure app is running on same port:

   npm run dev & npx wait-on http://localhost:3000
   npx cypress run

Docs

• Cypress network stubbing: https://docs.cypress.io/api/commands/intercept
• Remix loaders: https://remix.run/docs/en/main/route/loaders
• Cypress baseUrl: https://docs.cypress.io/guides/references/configuration#e2e

If this helps, please Mark as answer so others can find it.