Write to socket only if it is open

[cardil]

Partially fixes cypress-io/cypress#17288

This patch ensures that we write to a socket that is, in fact, open. This prevents exceptions from being thrown, like evidenced in cypress-io/cypress#17288.

After merge, this needs to be bundled into cypress to fix cypress-io/cypress#17288 fully.

[cardil]

/cc @flotwig

[flotwig]

Hey @cardil thanks for opening this. Sorry that this flew under the radar. We're working on improving our issue management processes on the team so this happens less often.

Can you please go ahead and create a PR to the cypress-io/cypress repo that points http-proxy to cardil/node-http-proxy#eec6ed5f0d65d34faf8bf90a1727764ebc334e81? That way we can run this change with the existing proxy tests.

packages/server/test/integration/websockets_spec.js is an excellent place to add a test for this. cypress-io/cypress#6945 should have had tests but didn't, because I wasn't sure what steps could reproduce this. These tests can be run via yarn test-integration websockets inside of packages/server

If the PR to cypress-io/cypress is passing, then this LGTM.

[cardil]

I'm not sure either what setup would be necessary to reproduce conditions in which the error occurs.

What I can assure that this change helps. After applying openshift-knative/serverless-operator#1099, we've stopped seeing the Error: This socket has been ended by the other party on our project.

[flotwig]

@cardil having a PR in cypress-io/cypress to point to this branch would let us know if this affects any of the existing websocket tests that we have in that repo before cutting a new release of @cypress/http-proxy that may break the actual cypress tests.

I'm not sure either what setup would be necessary to reproduce conditions in which the error occurs.

I'll try to add tests to your PR there if it doesn't break any of the CI in that repo, but if it ends up being a rabbithole, we can get this merged without it.

[nanek]

Thanks @cardil for this fix! I can also confirm after manually applying this change, I have stopped seeing Error: This socket has been ended by the other party in cypress.

[akshaygupta5233]

Hi @nanek . Need your help in setting this up,

[JamesNimlos]

This is still an issue so I went ahead and made a PR to the main Cypress repository to validate this doesn't break existing proxy workflows here: cypress-io/cypress#29453

[jennifer-shehane]

@JamesNimlos Thanks, we'll take a new look at this again.

[AtofStryker]

closing in favor of cypress-io/cypress#29499