This repository shows how to use QuviQ’s QuickCheck Mini in Elixir.
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Download QuickCheck Mini: http://www.quviq.com/downloads/
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Unpack zip somewhere ie. ~/eqcmini-2.01.0/
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Run iex in this directory
$ cd ~/eqcmini-2.01.0/ $ sudo iex
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Run following command in iex:
iex(1)> :eqc_install.install() Installation program for "Quviq QuickCheck Mini" version 2.01.0. Installing in directory /usr/lib/erlang/lib. Installing ["eqc-2.01.0"]. Quviq QuickCheck Mini is installed successfully. Bookmark the documentation at /usr/lib/erlang/lib/eqc-2.01.0/doc/index.html. :ok
QuickCheck Mini is now installed on your local Erlang VM. Do it once per development machine. You don't do it in production.
Add :eqc_ex dependency.
defp deps do
[
{:eqc_ex, "~> 1.2"}
]
end
Run mix deps.get and mix test. You will get following error:
== Compilation error on file lib/eqc/mocking.ex ==
** (RuntimeError) error parsing file /usr/lib/erlang/lib/eqc-2.01.0/include/eqc_mocking_api.hrl, got: {:error, :enoent}
Now, you will google and you will get this issue: Quviq/eqc_ex#3 Important part:
There is no free version with eqc_mocking in it, thus it won't work.
This means that :eqc_ex will not work with QuickCheck Mini. Or is it?
Edit deps/eqc_ex/lib/eqc/mocking.ex and comment lines 25-27:
#Record.defrecord :api_spec, Record.extract(:api_spec, from_lib: "eqc/include/eqc_mocking_api.hrl")
#Record.defrecord :api_module, Record.extract(:api_module, from_lib: "eqc/include/eqc_mocking_api.hrl")
#Record.defrecord :api_fun, Record.extract(:api_fun, from_lib: "eqc/include/eqc_mocking_api.hrl")
Compile deps using mix compile. Everything works now.
Check test/elixir_quickcheck_example.exs. This test was used on ElixirConf EU 2015:
https://www.youtube.com/watch?v=nbpZRm9gl50
Run mix test and... it fails:
** (CompileError) test/elixir_quickcheck_example_test.exs:8: function equals/2 undefined
After checking :eqc_ex sources, change equals/2 into ensure a == b:
# equals(:lists.seq(m, n), Enum.to_list(m..n))
ensure :lists.seq(m, n) == Enum.to_list(m..n)
Run mix test and it works:
$ mix test
....Failed! After 5 tests.
{1,0}
not ensured: [] == [1, 0]
Shrinking x(0 times)
{1,0}
not ensured: [] == [1, 0]
1) test Property Erlang sequence (ElixirQuickcheckExampleTest)
test/elixir_quickcheck_example_test.exs:6
forall({m, n} <- {int, int}) do
ensure(:lists.seq(m, n) == Enum.to_list(m .. n))
end
Failed for {1, 0}