polytropos-quickcheck

Property-based testing integration connecting polytropos open records and variants to QuickCheck.

Overview

polytropos-quickcheck provides Arbitrary instances for Record and Variant, enabling automated test generation and slot-by-slot shrinking.

Features

• Slot-by-Slot Shrinking: Shrinks records one field at a time without Cartesian product state space blowup.
• Branch-Preserving Variant Shrinking: Generates constructor variants uniformly and shrinks values strictly within the active constructor branch.
• Heterogeneous Generation: Derives generators across all fields using AllFields Arbitrary r.

Quick Example

{-# LANGUAGE BlockArguments #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE OverloadedRecordDot #-}
{-# LANGUAGE TypeApplications #-}
{-# OPTIONS_GHC -fplugin=Polytropos.Plugin #-}

import Test.QuickCheck
import Polytropos
import Polytropos.QuickCheck

type User = Record '["id" ':= Int, "name" ':= String, "active" ':= Bool]

-- Slot-indexed shrinking shrinks one field at a time without Cartesian explosion
prop_roundtrip :: Property
prop_roundtrip = forAll (arbitrary @User) \u ->
  u.id == u.id && not (null u.name)

License

Dual-licensed under EUPL-1.2 OR Apache-2.0.