improve e2e test

[ortex]

fixes #101

[coveralls]

coverage: 95.037%. remained the same when pulling 5529624 on improve_e2e_test into c859e77 on main.

[gavv]

Nice!

I few suggestions:

• Test waits until it receives first non-zero sample, then receives 10000 samples, then checks that each one is either zero or has correct value; it means that if we received one non-zero sample, and then 10000 zeros, the test will pass. Instead of this, I suggest to remove upper limit for how much samples we receive, and instead place lower limit of how much non-zero samples we want. So we will receive samples, check that each one is either zero or correct, and repeat this until we accumulate N non-zero samples. This way the test will check that there are a lot (N) of good samples, and at the same time it won't be bound to a particular loss ratio. Losses may happen on a loaded CI worker.

• 100 samples is not very interesting number - they will fit in one packet. I suggest to wait until we receive something like 10K non-zero samples, so that it will be many packets.

• To avoid unintuitive part with 0.5, we can work with integers:

  valueL = int(samples[i*2] * 100)
  assert((prevValue + 1) % 100 == valueL)
  

• When assertions fails, it makes sense to report index and maybe dump the whole stream or block.

• Let's replace magical number 2 with a constant like NumChan(nel)s.

[ortex]

• When assertions fails, it makes sense to report index and maybe dump the whole stream or block.

--- FAIL: TestEnd2End_Default (0.42s)
    e2e_test.go:146: 
                Error Trace:    /Users/andreybushmin/workspace/roc/roc-go/roc/e2e_test.go:146
                Error:          Not equal: 
                                expected: 2
                                actual  : 3
                Test:           TestEnd2End_Default
                Messages:       prevL: 1, valueL: 2, index: 2, samples: [0=0.01, 1=-0.01, 2=0.02, 3=-0.02, 4=0.03, 5=-0.03, 6=0.04, 7=-0.04, 8=0.05, 9=-0.05, 10=0.06, 11=-0.06, 12=0.07, 13=-0.07, 14=0.08, 15=-0.08, 16=0.09, 17=-0.09, 18=0.10, 19=-0.10, 20=0.11, 21=-0.11, 22=0.12, 23=-0.12, 24=0.13, 25=-0.13, 26=0.14, 27=-0.14, 28=0.15, 29=-0.15, 30=0.16, 31=-0.16, 32=0.17, 33=-0.17, 34=0.18, 35=-0.18, 36=0.19, 37=-0.19, 38=0.20, 39=-0.20, 40=0.21, 41=-0.21, 42=0.22, 43=-0.22, 44=0.23, 45=-0.23, 46=0.24, 47=-0.24, 48=0.25, 49=-0.25, 50=0.26, 51=-0.26, 52=0.27, 53=-0.27, 54=0.28, 55=-0.28, 56=0.29, 57=-0.29, 58=0.30, 59=-0.30, 60=0.31, 61=-0.31, 62=0.32, 63=-0.32, 64=0.33, 65=-0.33, 66=0.34, 67=-0.34, 68=0.35, 69=-0.35, 70=0.36, 71=-0.36, 72=0.37, 73=-0.37, 74=0.38, 75=-0.38, 76=0.39, 77=-0.39, 78=0.40, 79=-0.40, 80=0.41, 81=-0.41, 82=0.42, 83=-0.42, 84=0.43, 85=-0.43, 86=0.44, 87=-0.44, 88=0.45, 89=-0.45, 90=0.46, 91=-0.46, 92=0.47, 93=-0.47, 94=0.48, 95=-0.48, 96=0.49, 97=-0.49, 98=0.50, 99=-0.50]

output example (changed assert to fail)

all other suggestions are fixed

[gavv]

Thanks!!