Properly testing an OTP application after initialization

[Max Lapshin]

I have tried EUnit very long ago and found it too error prone, when I
understood that simply forgetting to put _ can lead to changing "list
of tests" to a "test that successfully returns a list".

And I don't see anything good in having 2000 lines of tests in the
same module which is only 300-400.


On Mon, Sep 14, 2020 at 2:25 PM Paulo F. Oliveira
<paulo.ferraz.oliveira@REDACTED> wrote:
>
> On Mon, 14 Sep 2020 at 06:07, Max Lapshin <max.lapshin@REDACTED> wrote:
>>
>> I do not understand what fixtures are for.
>
>
> It's explained in http://erlang.org/doc/apps/eunit/chapter.html#Fixtures: A "fixture" is some state that is necessary for a particular set of tests to run. EUnit's support for fixtures makes it easy to set up such state locally for a test set, and automatically tear it down again when the test set is finished, regardless of the outcome (success, failures, timeouts, etc.).
>
>>
>> We test our flussonic in this manner:
>>
>> init_per_suite(Config) ->
>>   application:ensure_all_started(flussonic)
>>   Config.
>>
>> ...
>>
>> end_per_suite(Config) ->
>>   application:stop(flussonic),
>>   Config.
>
>
> This is probably because you're using Common Test, and not EUnit.
>
> EUnit can be easily integrated into a module (without having to have a separate test/ folder and other "boilerplate" stuff), via -ifdef(TEST). fun_test() ..., and fixtures just make it that easy to keep all the code in the same place.