June 29th, 2022

golang testing

Finding flakey tests

Using teststat
- https://github.com/vearutop/teststat
- `go test -count 5 -race -json ./… | teststat -

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Metrics: map[cont:2 data_race:2 fail:6 flaky:6 output:826 pass:159 run:165 slow:100]
Elapsed: 7m5.169999999s
Slow: 7m3.559999999s
Test time distribution (seconds):
[  min   max] cnt total%    sum (165 events)
[ 0.00  0.00]  35 21.21%   0.00 .....................
[ 0.01  0.03]  15  9.09%   0.26 .........
[ 0.05  0.07]  10  6.06%   0.58 ......
[ 0.15  0.17]   5  3.03%   0.77 ...
[ 1.33  1.35]  10  6.06%  13.36 ......
[ 2.28  3.08]  55 33.33% 140.53 .................................
[ 3.75  4.00]  20 12.12%  77.48 ............
[ 8.15  8.49]   5  3.03%  41.31 ...
[12.22 12.74]   5  3.03%  61.86 ...
[17.66 18.20]   5  3.03%  89.02 ...

Race detection

Always test with -race
- Found two issues using this on my tests
  - First, I was running go routines and appending a slice of errors without waiting for the routines to finish before returning.
  - Second, the slice was being appened to without synchronisation.