StreamdataDemo

Just a demo of the Elixir streamdata module. It implements the first example from https://propertesting.com/book_stateless_properties.html in Elixir.

Example run

$ mix test
Compiling 1 file (.ex)
GENERATED LIST: [-1]
GENERATED LIST: [1, -1]
GENERATED LIST: [-2]
GENERATED LIST: [-3]
GENERATED LIST: [3, -1, 1, 1, 3]
GENERATED LIST: [-1, 1, 1, 3]
GENERATED LIST: [1, 1, 3]
GENERATED LIST: [1, 3]
GENERATED LIST: [1, 3]
GENERATED LIST: [1, 1]
GENERATED LIST: [1]
GENERATED LIST: [1]


  1) property Find biggest number in list (StreamdataDemoTest)
     test/streamdata_demo_test.exs:5
     ** (ExUnitProperties.Error) failed with generated values (after 4 successful run(s)):

     list <- nonempty(list_of(integer()))
     #=> [1, 1]

         ** (FunctionClauseError) no function clause matching in StreamdataDemo.biggest/2
     code: check all list <- nonempty(list_of(integer())) do
     stacktrace:
       (streamdata_demo) lib/streamdata_demo.ex:3: StreamdataDemo.biggest([1], 1)
       test/streamdata_demo_test.exs:8: anonymous fn/2 in StreamdataDemoTest."property Find biggest number in list"/1
       (stream_data) lib/stream_data.ex:1974: StreamData.shrink_failure/6
       (stream_data) lib/stream_data.ex:1938: StreamData.check_all/6
       test/streamdata_demo_test.exs:6: (test)



Finished in 0.07 seconds
1 property, 1 failure

Randomized with seed 219726