Protocol not implemented in tests

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1

I have some modules that I want to implement a protocol for:

defmodule A do
end

defmodule B do
end

defmodule Foo do
  def all(), do: [A, B]
end

defprotocol Fooer do
  def x(f)
end

defimpl Fooer, for: A do
  def x(_), do: ""
end

defimpl Fooer, for: B do
  def x(_), do: ""
end

and a simple test

defmodule FooerTest do
  use ExUnit.Case, async: false

  for fooer <- Foo.all() do
    test "protocol implemented for #{inspect(fooer)}" do
      assert "" == Fooer.x(unquote(fooer))
    end
  end
end

but running this test, I get:

  1) test protocol implemented for A (FooerTest)
     test/foo_test.exs:5
     ** (Protocol.UndefinedError) protocol Fooer not implemented for A of
 type Atom. This protocol is implemented for the following type(s): B, A
     code: assert "" == Fooer.x(unquote(fooer))
     stacktrace:
       (dashboard) lib/foo.ex:11: Fooer.impl_for!/1
       (dashboard) lib/foo.ex:12: Fooer.x/1
       test/foo_test.exs:6: (test)



  2) test protocol implemented for B (FooerTest)
     test/foo_test.exs:5
     ** (Protocol.UndefinedError) protocol Fooer not implemented for B of
 type Atom. This protocol is implemented for the following type(s): B, A
     code: assert "" == Fooer.x(unquote(fooer))
     stacktrace:
       (dashboard) lib/foo.ex:11: Fooer.impl_for!/1
       (dashboard) lib/foo.ex:12: Fooer.x/1
       test/foo_test.exs:6: (test)

I guess I’m running into some issues with the dynamic generation of the test or something similar? Anyone has an idea on how to fix this?

2

Well, let’s just ignore this. It’s been a while since I’ve used protocols, and kinda forgot that it works with structs instead of modules…
So the question is invalid.

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