Intercept network activity (request / response) to run assertions

[holek10]

An idea to add feature for intercepting network activity - responses & requests - to enable tests that rely on these items.
Similar functionality that already exists in other automation tools out there, like Cypress for example.

[asafkorem]

Hey @holek10, thanks for suggesting this idea. I can see why this can be useful.
However, currently, that's something that can be achieved using mocking.

[jar0s]

Hi @asafkorem
Thank you for the suggestions. The one with getAttributes() sounds like it could work.
I also like the idea with WebSocket as it may result in a cleaner implementation.
We'll play with them both a bit and see.
Cheers.

[jar0s]

Hi @asafkorem ,
I just wanted to let you know (and for anyone else reading this thread in the future) that the solution with WebSocket worked for us.
We start a WS server in the Detox test process and connect to it from a mocked analytics module within the app. The mocked module sends all analytics events through the WebSocket so they can be verified within e2e tests.

The part with having the WebSocket server running in the same Node process as Detox tests seems pretty generic so I wonder if this might be something worth contributing back to the Detox itself to enable communication between the app and the test process in general? What do you think?
How we've done it is that the tests can subscribe to the topics of interest and WS server broadcasts the messages to specific subscribers based on the topics (and this mechanism is pretty generic as well).

[asafkorem]

Hi @jar0s, sorry for noticing this in such delay. Glad to hear that it worked out for you!
I'm not sure if such feature should be part of Detox itself. However, we already have some contribution that does that #3245, and based on the demand, I guess it worth thinking about this.

[jar0s]

Hi @asafkorem
I think #3245 solves a "reverse" challenge. It allows injecting something into the app (detox test process -> the app). What we needed and implemented with WebSocket is the app sending info to the Detox test process (the app -> detox test process).
I see both as supplementary solutions serving different use cases.

[asafkorem]

Thanks for letting us know that the issue has been resolved, @jar0s. If this is still relevant for you or anyone else reading this thread, you may want to consider using MSW as a solution. It seems that someone has successfully used it with Detox tests, as mentioned in this GitHub issue.