hedgehog-inline-csharp-testing

Example of using haskell-hedgehog's model-based state machine testing together with clr-inline (C#).

Points of Interest

• The code under test, a circular buffer implemented in C#: CircularBuffer.hs (clr-inline provides a quasiquoter to inline F# and C# code in Haskell modules)
• The code wrapping our circular buffer class, providing a Haskell API: CircularBuffer.hs
• The tests, test.hs, including:
  • A simplified model of a circular buffer (the Model data type)
  • The commands of the API (New, Get, Put, Size), with generators, pre and post-conditions, and model update functions
  • A Hedgehog property running sequential generative tests on the model and the C#-implemented CircularBuffer to verify that they behave the same

References

Translated from Oskar Wickström's example:

The example used, the circular buffer and its model, is based on the paper Experiences with QuickCheck: Testing the Hard Stuff and Staying Sane, by John Hughes. In the original paper the code under test in written C, and the tests in Erlang and Quviq QuickCheck; in this example testing a Java implementation using Haskell and the Hedgehog library.

That example is licensed under BSD3, and so is this code.

Build Requirements

This has only been tested and hacked on using Stack and .NET Framework. Adding support for .NET Core in clr-inline is something I consider working on.

Make sure csc.exe and fsc.exe are in PATH; for the Community edition of Microsoft Visual Studio this means:

• C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\bin\Roslyn
• C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\FSharp

You should be able to run the following using a recent Stack version:

$ stack build --test
hedgehog-inline-csharp-testing-0: unregistering (local file changes: README.md)
hedgehog-inline-csharp-testing-0: configure (lib + test)
Configuring hedgehog-inline-csharp-testing-0...
hedgehog-inline-csharp-testing-0: build (lib + test)
Preprocessing library for hedgehog-inline-csharp-testing-0..
Building library for hedgehog-inline-csharp-testing-0..
[1 of 1] Compiling CircularBuffer <...>
Microsoft (R) Visual C# Compiler version 2.9.0.63208 (958f2354)
Copyright (C) Microsoft Corporation. All rights reserved.

Preprocessing test suite 'test' for hedgehog-inline-csharp-testing-0..
Building test suite 'test' for hedgehog-inline-csharp-testing-0..
[1 of 1] Compiling Main <...>
Linking .stack-work\dist\5c8418a7\build\test\test.exe ...
hedgehog-inline-csharp-testing-0: copy/register
Installing library in <...>
Registering library for hedgehog-inline-csharp-testing-0..
hedgehog-inline-csharp-testing-0: test (suite: test)

━━━ Main ━━━
  ✓ prop_circular_buffer_sequential passed 25 tests.
  ✓ 1 succeeded.

hedgehog-inline-csharp-testing-0: Test suite test passed
Completed 2 action(s).