1

I would like to use meck in different ExUnit test file.

For example,

[x_test.exs]

def setup do
  :meck.new(Hoge, [:passthrough])
　on_exit(fn -> :meck.unload end)
　:ok
end

def teardown do
  :meck.unload
end

test "foo" do
  :meck.expect(Hoge, :foo, fn -> 1 end)
  assert Hoge.foo == 1
end

[y_test.exs]

def setup do
  :meck.new(Hoge, [:passthrough])
　on_exit(fn -> :meck.unload end)
　:ok
end

def teardown do
  :meck.unload
end

test "foo" do
  :meck.expect(Hoge, :foo, fn -> 2 end)
  assert Hoge.foo == 2
end

Sometimes, x_test.exs is fail, but sometimes, x_test.exs is success... (y_test.exs is same)

Can I use mock to same function in another test file?

tamagohan2
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1 Answers1

2

meck currently compiles and loads code you specified with your expectations. As only one current version of the code could be loaded inside the beam you should execute all tests that race for the same mocked function sequentially.

As ExUnit documentation states that test cases are executed in parallel, you probably have to merge all the tests that should be executed serially in the single test case (i.e. single test module).

Alternatively, you could set number of test cases that could be executed in parallel to 1. However it could slow down your test run

ExUnit supports the following options:

  • :max_cases - maximum number of cases to run in parallel; defaults to :erlang.system_info(:schedulers_online)
Community
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Lol4t0
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  • Thank you! I understand that test cases are executed in parallel. So, I try to call "meck.new" in each test case. (not call in setup) In that case, test is not failed. – tamagohan2 Oct 22 '15 at 12:28
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    @user4252489 you get classic race condition over the resource (code) here. You _have to_ synchronize, otherwise your test will be **unreliable**. Calling `meck:new` in every test is not enough – Lol4t0 Oct 22 '15 at 12:31
  • Or just bypass mocking altogether. http://blog.plataformatec.com.br/2015/10/mocks-and-explicit-contracts/ – Onorio Catenacci Oct 22 '15 at 17:36
  • Thank you for reply. > you get classic race condition over the resource (code) here. You have to > synchronize, otherwise your test will be unreliable. Calling meck:new in > > every test is not enough Oh... > Or just bypass mocking altogether I would like to mock System.cmd ... I try to use "async" option of exunit. But, failed.. – tamagohan2 Oct 24 '15 at 14:14