rewire
===
[](https://travis-ci.org/stephanos/rewire)
Keep your code free from dependency injection and mocking concerns by using `rewire` in your unit tests to stub out any module dependencies:
```elixir
defmodule MyModule do
def do_something(), do: MyDep.foo()
end
defmodule MyTest do
use ExUnit.Case
use Rewire
defmodule MyMock do
def foo(), do: "bar"
end
test "my test" do
rewire MyModule, MyDep: MyMock do
assert MyModule.foo() == "bar"
end
end
end
```
## FAQ
**Witchcraft! How does this work??**
Simply put, `rewire` will create a copy of the module to rewire under a new name at runtime, replacing all hard-coded module references that should be changed in the process. Plus, it rewrites the test code in the `rewire` block to use the generated module instead.
**Will that slow down my tests?**
Possibly just a little? Conclusive data isn't in yet.
**Does it work with `mox`?**
It works great with [mox](https://github.com/dashbitco/mox) since `rewire` doesn't care about where the replacement module comes from. `rewire` and `mox` are a great pair!
