I’m using using mox to help me with my unit testing (for now, I want to mock a function that fetches external API). my mix.exs : {:mox, "~> 1.0", only: :test} My test_helper.exs : ExUnit.start() Mox.defmock(MyApp.MockExternalSources, for: MyApp.MyModule.ExternalSources) My module code (MyApp.M…

Did you clear / trigger application rebuilt after introducing the Mox mock? I think I was having similar problem and I had to trigger application recompilation, by either mix clear or even removing the whole _build dir and rebuilding it from scratch.

Hi @hubertlepicki , yes I did but the same result. I think there is something missing (an implementation or something ?) to detect the mocked function

Hi! You are missing env variables. In test_helpers you need to put Application.put_env(:app_name, :external, MyApp.MockExternalSources) and in test you need to call it in this way: Application.get_env(:app_name, :external).fetch_one_external_resource and mock in test fetch_one_external_resour…

Hi @karlosmid , I have this error : ** (Mox.UnexpectedCallError) no expectation defined for MyApp.MockExternalSources.fetch_one_external_resource/1 in process #PID<0.529.0> with args Maybe I didn’t get it right, can you please help me add your proposition to my code ?

Mox was expecting fetch_one_external_resource/1 as the name of the function to be called, but your expectation is calling another function.

Yes because I mocked the http_get_resource/2 which does the HTTP call, I just need to simulate that behaviour not the entire fetch_one_external_resource/1 function Can anyone please show me what’s wrong ? Here is the updates that I did based on @karlosmid answer. in test_helper.ex : I added ; …

[image] karlosmid: and mock in test fetch_one_external_resource function instead of http_get_resource. If I mock fetch_one_external_resource there will not be a real test, It will be a static verification of the result

The core problem is that it’s not enough to create a mock from a behaviour, you should also tell your implementation to use it in tests. Right now, your fetch_one_external_resource is always calling http_get_resource . The implementation is fixed. As others have already pointed out: Refactor http…

Or you could just use Patch :wink:

@trisolaran , here is all the updates that I did by I always get an empty left in assertion (left: %{}) In ExternalSources module, I added : @api_client Application.compile_env!(:app_name, :api_client) The call to the http_get_resource became : @api_client.http_get_resource(url, headers) In te…

Mox is ignoring my Mocked module and calling the real function

Questions & Help Questions

dorgan January 11, 2023, 9:25am 10

Or you could just use Patch