Refactor unit tests with hardcoded ports

[ccoVeille]

The tests are using hardcoded port, it's not a good pattern. Unit tests cannot be launched in parallel.

Any of these packages could be used

https://github.com/facebookarchive/freeport
https://github.com/projectdiscovery/freeport
https://github.com/phayes/freeport
https://github.com/Konstantin8105/FreePort
https://github.com/jamielxcarter/dort
https://github.com/prithviramesh/free-port-finder

Of course, as the feature is very basic, it could be added via a simple helper. By copy pasting something like this.

https://gist.github.com/sevkin/96bdae9274465b2d09191384f86ef39d

From a library with a copyleft license

[ccoVeille]

Here is an example

https://github.com/gofr-dev/gofr/blob/development/pkg%2Fgofr%2Fhttp%2Frouter_test.go

All the tests are using the 8080 port.

I didn't check further, and maybe it's a bad example as calls are mocked, but there are unit tests, that expect ports to be available.

Imagine code expecting the 8080 port to be available, but the developer has a webserver, proxy, whatsoever.

The unit tests will fail and the developer will become nuts before thinking about the local webserver hosted on :8080

[vikash]

This is a great idea - whenever we are actually testing a call over a port.