Search code examples
mockingelixirphoenix-frameworkectostubbing

How to mock/stub methods in Elixir library Ecto/Repo?

Tell me please how to mock/stub methods of Repo module for my tests?

For ex.:

  link = Repo.get_by(Link, short_url: url)
  db_count = Repo.aggregate(Link, :count, :id)

I need that Repo.aggregate returns 10000000000 for my tests. The same with Repo.get_by.

How to do it?

And what is the best approach for module isolation in tests in Elixir?

Thanks!

Solution

  • Here's an example from https://github.com/gialib/ex_mock readme:

    defmodule MyTest do
  use ExUnit.Case, async: false

  import ExMock

  test "test_name" do
    with_mock HTTPotion, [get: fn(_url) -> "<html></html>" end] do
      HTTPotion.get("http://example.com")
      # Tests that make the expected call
      assert called HTTPotion.get("http://example.com")
    end
  end
end