Great, I chose (1), as it’s a bit more explicit. This also removed the need for the Code.load_file. Thanks!

Excellent question! I am assuming you are using Elixir v1.2 as since this version Elixir consolidate protocols by default during compilation, which means that any protocol defined during tests won’t be part of the consolidation. You have two options here.

1. The first is to include “test/support” in your compilation paths for the test environment. Phoenix for examples does it for new applications: https://github.com/phoenixframework/phoenix/blob/master/installer/templates/new/mix.exs#L30-L31

2. The second option is to disable protocol consolidation for tests. Just set “consolidate_protocols: Mix.env != :test” in def project in your mix.exs.

You mention using data structures and defining protocols. On day one of learning Elixir this was what I reached for, but ran into a problem loading the fake implementation in test.

I created my project with ‘mix new’. It has a protocol named RemoteCaller, and I’m passing in a %FakeRemoteCaller{} to a function. That fake looks like this:


defmodule FakeRpcCaller do
defstruct []
end

defimpl RemoteCaller, for: FakeRpcCaller do
def call(node, mod, fun, args) do
[0, [:something], nil]
end
end


The test is doing Code.load_file("test/fake_remote_caller.ex"). With fake_remote_caller.ex (or .exs) in the test/ dir, I get:

** (Protocol.UndefinedError) protocol RemoteCaller not implemented for %FakeRpcCaller{}

However, when it’s in the lib/ dir, all works fine. What’s going on here? Thanks!

How exactly would the pipeline definition look in the Phoenix Router. For example, I have the following two pipelines defined which functioned correctly before adding in this test mock config:

pipeline :secure do
plug :fetch_access_token
plug :authenticate_user
plug :fetch_user
plug :validate_permission, [level: :user, action: :edit]
plug :validate_permission, [level: :user, action: :view]
end

pipeline :admin_edit do
plug :validate_permission, [level: :admin, action: :edit]
end

That’s because import works at expansion/compile time and the Application.get_env is performed at runtime. You won’t be able to use import. You will need to use the `module.function(args)` syntax.