Hi all I am reading the phoenixframework book and says in the testing section, that we should avoid mocks for testing why? Thanks

José - the creator of Elixir - explained it beautifully here: Mocks and explicit contracts « Plataformatec Blog Our test tools often make it very easy to abuse mocks. This post provides some guidelines on using them properly by relying on explicit contracts. …

Even it is written by José I am not entirely agreeing with the gist of it. Don’t get me wrong, The abuse of mocking is there and especially a decade and more ago mocking was a fashion, had lots of traction and was - also helped by tools - “state of the art”. That we can abuse it should not let us t…

Hi Kujua, as far as I remember the general idea is that (to) mock, the verb, is bad and mock, the noun, is good. An example would be when we make an HTTP call to the GitHub-API to authorize a user via OAuth: If we mock (verb) the “calling an HTTP interface” part, that is bad design. If we wr…

Firstly, the “verb/noun” distinction has a root in OOP and I believe it is not relevant in Elixir, mocking or not. Secondly, José’s article is bringing the options of stubs (changing them in the configuration) and testing the real thing. (There is a discussion about the difference of mocks [the "no…

[image] kujua: we should aim at functions that are free of side effects and dependency injection is a side effect. Hard to argue with that.

@rrrene :slight_smile: Actually it is not to argue, I really would like to have a discussion about this. Testing itself (TDD or something else) is a good theory, in practice it falls foul of deadlines, project management demands and developer’s (my) own laziness. I think as an industry we don’t hav…

I would strongly disagree that dependency injection is an OO concept. In fact I will even say that dependency injection is bread and butter of functional programming. How? Higher order functions. What is a higher order function if not a function where we “inject” the dependency - the code that execu…

Firstly, the “verb/noun” distinction has a root in OOP and I believe it is not relevant in Elixir, mocking or not. That’s pointing to the wrong direction. First of all, OOP and FP are not mutually exclusive domains. They are properties shared by both paradigms. I will come back to this later on. …

[image] michalmuskala: Having said that, passing the dependency through application environment is indeed a side-effect and may be not considered a good style, but it’s very simple and convenient. I partially agree. If the value never changes, it will be side-effect free. That’s exactly what …

You cannot reassign values in Elixir. While it looks like rebinding it is not.

I would also say that avoiding side-effects is not the same thing as no side effects. Side effects are not bad. Unintentional side effects are bad.

Why avoid mocks

Questions & Help Questions

rrrene August 18, 2016, 8:04pm 2

José - the creator of Elixir - explained it beautifully here: