Mocks and explicit contracts in Elixir
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axelson and josevalim Creating an allowance in global mode is now ignored (#48)
This can be useful if you create a shim to assist in testing. Now you can use
your shim all of the time without having to know if Mox is in global mode or not.

Fixes #46
Latest commit d1b102e Oct 9, 2018


Mox is a library for defining concurrent mocks in Elixir.

The library follows the principles outlined in "Mocks and explicit contracts", summarized below:

  1. No ad-hoc mocks. You can only create mocks based on behaviours

  2. No dynamic generation of modules during tests. Mocks are preferably defined in your test_helper.exs or in a setup_all block and not per test

  3. Concurrency support. Tests using the same mock can still use async: true

  4. Rely on pattern matching and function clauses for asserting on the input instead of complex expectation rules

See the documentation for more information.


Just add mox to your list of dependencies in mix.exs:

def deps do
    {:mox, "~> 0.4", only: :test}

Mox should be automatically started unless the :applications key is set inside def application in your mix.exs. In such cases, you need to remove the :applications key in favor of :extra_applications or call Application.ensure_all_started(:mox) in your test/test_helper.exs.


Copyright 2017 Plataformatec

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