A simple way to describe dependencies that can be replaced at test time.
If available in Hex, the package can be installed as:
- Add
injexto your list of dependencies inmix.exs:
```elixir
def deps do
[{:injex, "~> 0.1.0"}]
end
```
In modules, instead of:
defmodule MyModule do
def process(data) do
changeset = # ...
Repo.insert(changeset)
end
endYou write:
defmodule MyModule do
import Injex
inject :repo, Repo
def process(data) do
changeset = # ...
repo.insert(changeset)
end
endThen, in your tests, you can replace Repo with a different one to simplify testing.
defmodule MyModuleTest do
use ExUnit.Case
import Injex.Test
defmodule Repo do
def insert(changeset), do: send(self, {:insert, changeset})
end
describe ".process" do
test "inserts data" do
override MyModule, repo: MyModuleTest.Repo do
MyModule.process(%{})
assert_received {:insert, changeset}
end
end
end
endThe inject macro will only include overriding capabilities when Mix.env is :test. Otherwise, it hardcodes the default dependency.