engine.io client in jest tests fails to connect with engine.io server

[jeduden]

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You want to:

• report a bug

Current behaviour

If running engine 3.1.3 ( and also socket.io 2 ) in jest, the client is not able to connect to the server.
Same test with jasmine works fine.

Steps to reproduce (if the current behaviour is a bug)

Since there are a couple of variants to consider; I created a repository:
https://github.com/jeduden/jest-issue

Expected behaviour

Be able to use engine.io 3 / socket.io 2 within jest test.

Setup

• OS: osx
• browser: node 8
• engine.io version: 3.1.3

Other information (e.g. stacktraces, related issues, suggestions how to fix)

Please refer to the repo: https://github.com/jeduden/jest-issue .
It includes logs, example code and variants of the issue.

Currently, I have no idea what the cause of this issue is. There was this issue socketio/socket.io#2381 but running socket.io 2 in a node sandboxe works just fine using jasmine.
uWS is also not the issue. It works fine in jest.

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Also filed this issue in the jest repo: jestjs/jest#4815

[darrachequesne]

Closed due to inactivity, please reopen if needed.