Created
August 26, 2017 20:58
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POC for type spec tests with StreamData.
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defmodule Math do | |
@spec square(integer) :: integer | |
def square(a) do | |
a * a | |
end | |
end |
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defmodule TypeTest do | |
use ExUnit.Case | |
import PropertyTest | |
property "types" do | |
module = Math | |
specs = Kernel.Typespec.beam_specs(module) | |
for {{name, _}, _} = spec <- specs, name != :__info__ do | |
{{function_name, _arity}, specs} = spec | |
for {:type, _, :fun, types} <- specs do | |
[{:type, _, :product, arguments}, result] = types | |
result_type = type(result) | |
[argument] = arguments | |
argument_gen = argument | |
|> type | |
|> generator | |
check all a <- argument_gen do | |
result = :erlang.apply(module, function_name, [a]) | |
checker(result_type).(result) | |
end | |
end | |
end | |
end | |
def generator(:integer), do: StreamData.integer() | |
def checker(:integer), do: fn(result) -> | |
assert is_integer(result) | |
end | |
def type({:type, _, type, _}), do: type | |
end |
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