rtypes_propcheck
The library implements a PropCheck generator backend for the RTypes library.
Usage
Let's suppose you defined a type and you have a function f/1 which
takes a value of that type and returns a value of some other type
defmodule MyModule do
@type foo :: %{key1: integer(), key2: Keyword.t()}
@type goo :: 1..512
@spec f(foo) :: goo
def f(a_foo) do
# ...
end
endNow, you want to write a property to ensure that your function is
total, that is, for any value that belongs to type foo you expect
the function to return a value of type goo.
You can achieve this as follows
defmodule MyTest do
use PropCheck
use ExUnit.Case
require RTypes.Generator, as Generator
require RTypes
property "f(foo) always returns goo" do
gen = Generator.make(MyModule.foo(), Generator.PropCheck)
goo? = RTypes.make_predicate(MyModule.goo())
forall value <- gen() do
goo?.(MyModule.f(value))
end
end
endSee test/rtypes_propcheck_test.exs for some examples.
