Copyright	(c) 2015--2018 Michael Walker
License	MIT
Maintainer	Michael Walker <mike@barrucadu.co.uk>
Stability	stable
Portability	FlexibleContexts, FlexibleInstances, LambdaCase, TypeSynonymInstances
Safe Haskell	None
Language	Haskell2010

Test.HUnit.DejaFu

Contents

Unit testing
Unit testing
- Re-exports
Refinement property testing
- Re-exports
Deprecated
Orphan instances

Description

This module allows using Deja Fu predicates with HUnit to test the behaviour of concurrent systems.

Synopsis

Unit testing

This is supported by the Assertable and Testable instances for ConcIO. These instances try all executions, reporting as failures the cases which throw an HUnitFailure exception.

instance Testable (ConcIO ()) instance Assertable (ConcIO ())

These instances use defaultWay and defaultMemType.

Unit testing

testAuto #

Arguments

:: (Eq a, Show a)
=> ConcIO a	The computation to test.
-> Test

Automatically test a computation. In particular, look for deadlocks, uncaught exceptions, and multiple return values.

Since: 1.0.0.0

testDejafu #

Arguments

:: Show b
=> String	The name of the test.
-> ProPredicate a b	The predicate to check.
-> ConcIO a	The computation to test.
-> Test

Check that a predicate holds.

Since: 1.0.0.0

testDejafus #

Arguments

:: Show b
=> [(String, ProPredicate a b)]	The list of predicates (with names) to check.
-> ConcIO a	The computation to test.
-> Test

Variant of testDejafu which takes a collection of predicates to test. This will share work between the predicates, rather than running the concurrent computation many times for each predicate.

Since: 1.0.0.0

testAutoWay #

Arguments

:: (Eq a, Show a)
=> Way	How to execute the concurrent program.
-> MemType	The memory model to use for non-synchronised `CRef` operations.
-> ConcIO a	The computation to test.
-> Test

Variant of testAuto which tests a computation under a given execution way and memory model.

Since: 1.0.0.0

testDejafuWay #

Arguments

:: Show b
=> Way	How to execute the concurrent program.
-> MemType	The memory model to use for non-synchronised `CRef` operations.
-> String	The name of the test.
-> ProPredicate a b	The predicate to check.
-> ConcIO a	The computation to test.
-> Test

Variant of testDejafu which takes a way to execute the program and a memory model.

Since: 1.0.0.0

testDejafusWay #

Arguments

:: Show b
=> Way	How to execute the concurrent program.
-> MemType	The memory model to use for non-synchronised `CRef` operations.
-> [(String, ProPredicate a b)]	The list of predicates (with names) to check.
-> ConcIO a	The computation to test.
-> Test

Variant of testDejafus which takes a way to execute the program and a memory model.

Since: 1.0.0.0

testAutoWithSettings #

Arguments

:: (Eq a, Show a)
=> Settings IO a	The SCT settings.
-> ConcIO a	The computation to test.
-> Test

Variant of testAuto which takes a settings record.

Since: 1.1.0.0

testDejafuWithSettings #

Arguments

:: Show b
=> Settings IO a	The SCT settings.
-> String	The name of the test.
-> ProPredicate a b	The predicate to check.
-> ConcIO a	The computation to test.
-> Test

Variant of testDejafu which takes a settings record.

Since: 1.1.0.0

testDejafusWithSettings #

Arguments

:: Show b
=> Settings IO a	The SCT settings.
-> [(String, ProPredicate a b)]	The list of predicates (with names) to check.
-> ConcIO a	The computation to test.
-> Test

Variant of testDejafus which takes a settings record.

Since: 1.1.0.0

Re-exports

type Predicate a = ProPredicate a a #

A Predicate is a function which collapses a list of results into a Result, possibly discarding some on the way.

Predicate cannot be a functor as the type parameter is used both co- and contravariantly.

Since: 1.0.0.0

data ProPredicate a b :: * -> * -> * #

A ProPredicate is a function which collapses a list of results into a Result, possibly discarding some on the way.

Since: 1.0.0.0

Constructors

ProPredicate
Fields pdiscard :: Either Failure a -> Maybe Discard Selectively discard results before computing the result. peval :: [(Either Failure a, Trace)] -> Result b Compute the result with the un-discarded results.

Instances

Profunctor ProPredicate
Methods dimap :: (a -> b) -> (c -> d) -> ProPredicate b c -> ProPredicate a d # lmap :: (a -> b) -> ProPredicate b c -> ProPredicate a c # rmap :: (b -> c) -> ProPredicate a b -> ProPredicate a c # (#.) :: Coercible * c b => (b -> c) -> ProPredicate a b -> ProPredicate a c # (.#) :: Coercible * b a => ProPredicate b c -> (a -> b) -> ProPredicate a c #
Functor (ProPredicate x)
Methods fmap :: (a -> b) -> ProPredicate x a -> ProPredicate x b # (<$) :: a -> ProPredicate x b -> ProPredicate x a #

module Test.DejaFu.Settings

Refinement property testing

testProperty #

Arguments

:: (Testable p, Listable (X p), Eq (X p), Show (X p), Show (O p))
=> String	The name of the test.
-> p	The property to check.
-> Test

Check a refinement property with a variety of seed values and variable assignments.

Since: 0.6.0.0

testPropertyFor #

Arguments

:: (Testable p, Listable (X p), Eq (X p), Show (X p), Show (O p))
=> Int	The number of seed values to try.
-> Int	The number of variable assignments per seed value to try.
-> String	The name of the test.
-> p	The property to check.
-> Test

Like testProperty, but takes a number of cases to check.

The maximum number of cases tried by testPropertyFor n m will be n * m.

Since: 0.7.1.0

Re-exports

data Sig s o x :: * -> * -> * -> * #

A concurrent function and some information about how to execute it and observe its effect.

s is the state type (MVar ConcIO a in the example)
o is the observation type (Maybe a in the example)
x is the seed type (Maybe a in the example)

Since: 0.7.0.0

Constructors

Sig
Fields initialise :: x -> ConcIO s Create a new instance of the state variable. observe :: s -> x -> ConcIO o The observation to make. interfere :: s -> x -> ConcIO () Set the state value. This doesn't need to be atomic, or even guaranteed to work, its purpose is to cause interference. expression :: s -> ConcIO () The expression to evaluate.

data RefinementProperty o x :: * -> * -> * #

A property which can be given to check.

Since: 0.7.0.0

Instances

Testable (RefinementProperty o x)
Associated Types type O (RefinementProperty o x) :: * # type X (RefinementProperty o x) :: * # Methods rpropTiers :: RefinementProperty o x -> [[([String], RefinementProperty (O (RefinementProperty o x)) (X (RefinementProperty o x)))]]
type X (RefinementProperty o x)
type X (RefinementProperty o x) = x
type O (RefinementProperty o x)
type O (RefinementProperty o x) = o

class Testable a #

Things which can be tested.

Since: 0.7.0.0

Minimal complete definition

rpropTiers

Associated Types

type O a :: * #

The observation value type. This is used to compare the results.

type X a :: * #

The seed value type. This is used to construct the concurrent states.

Instances

(Listable a, Show a, Testable b) => Testable (a -> b)
Associated Types type O (a -> b) :: * # type X (a -> b) :: * # Methods rpropTiers :: (a -> b) -> [[([String], RefinementProperty (O (a -> b)) (X (a -> b)))]]
Testable (RefinementProperty o x)
Associated Types type O (RefinementProperty o x) :: * # type X (RefinementProperty o x) :: * # Methods rpropTiers :: RefinementProperty o x -> [[([String], RefinementProperty (O (RefinementProperty o x)) (X (RefinementProperty o x)))]]

class Listable a where #

A type is Listable when there exists a function that is able to list (ideally all of) its values.

Ideally, instances should be defined by a tiers function that returns a (potentially infinite) list of finite sub-lists (tiers): the first sub-list contains elements of size 0, the second sub-list contains elements of size 1 and so on. Size here is defined by the implementor of the type-class instance.

For algebraic data types, the general form for tiers is

tiers = cons<N> ConstructorA
     \/ cons<N> ConstructorB
     \/ ...
     \/ cons<N> ConstructorZ

where N is the number of arguments of each constructor A...Z.

Instances can be alternatively defined by list. In this case, each sub-list in tiers is a singleton list (each succeeding element of list has +1 size).

The function deriveListable from Test.LeanCheck.Derive can automatically derive instances of this typeclass.

A Listable instance for functions is also available but is not exported by default. Import Test.LeanCheck.Function if you need to test higher-order properties.

Minimal complete definition

list | tiers

Methods

tiers :: [[a]] #

list :: [a] #

Instances

Listable Bool	tiers :: [[Bool]] = [[False,True]] list :: [[Bool]] = [False,True]
Methods tiers :: [[Bool]] # list :: [Bool] #
Listable Char
Methods tiers :: [[Char]] # list :: [Char] #
Listable Double
Methods tiers :: [[Double]] # list :: [Double] #
Listable Float
Methods tiers :: [[Float]] # list :: [Float] #
Listable Int	tiers :: [[Int]] = [[0], [1], [-1], [2], [-2], [3], [-3], ...] list :: [Int] = [0, 1, -1, 2, -2, 3, -3, 4, -4, 5, -5, 6, ...]
Methods tiers :: [[Int]] # list :: [Int] #
Listable Integer
Methods tiers :: [[Integer]] # list :: [Integer] #
Listable Ordering
Methods tiers :: [[Ordering]] # list :: [Ordering] #
Listable ()
Methods tiers :: [[()]] # list :: [()] #
Listable a => Listable [a]	tiers :: [[ [Int] ]] = [ [ [] ] , [ [0] ] , [ [0,0], [1] ] , [ [0,0,0], [0,1], [1,0], [-1] ] , ... ] list :: [ [Int] ] = [ [], [0], [0,0], [1], [0,0,0], ... ]
Methods tiers :: [[[a]]] # list :: [[a]] #
Listable a => Listable (Maybe a)	tiers :: [[Maybe Int]] = [[Nothing], [Just 0], [Just 1], ...] tiers :: [[Maybe Bool]] = [[Nothing], [Just False, Just True]]
Methods tiers :: [[Maybe a]] # list :: [Maybe a] #
(Listable a, Listable b) => Listable (Either a b)
Methods tiers :: [[Either a b]] # list :: [Either a b] #
(Listable a, Listable b) => Listable (a, b)	tiers :: [[(Int,Int)]] = [ [(0,0)] , [(0,1),(1,0)] , [(0,-1),(1,1),(-1,0)] , ...] list :: [(Int,Int)] = [ (0,0), (0,1), (1,0), (0,-1), (1,1), ...]
Methods tiers :: [[(a, b)]] # list :: [(a, b)] #
(Listable a, Listable b, Listable c) => Listable (a, b, c)
Methods tiers :: [[(a, b, c)]] # list :: [(a, b, c)] #
(Listable a, Listable b, Listable c, Listable d) => Listable (a, b, c, d)
Methods tiers :: [[(a, b, c, d)]] # list :: [(a, b, c, d)] #
(Listable a, Listable b, Listable c, Listable d, Listable e) => Listable (a, b, c, d, e)	Instances for `Listable` sixtuples up to 12-tuples are exported by default form Test.LeanCheck but are hidden from Haddock documentation. These instances are defined in Test.LeanCheck.Basic.
Methods tiers :: [[(a, b, c, d, e)]] # list :: [(a, b, c, d, e)] #

expectFailure :: RefinementProperty o x -> RefinementProperty o x #

Indicates that the property is supposed to fail.

refines :: Ord o => Sig s1 o x -> Sig s2 o x -> RefinementProperty o x #

Observational refinement.

True iff the result-set of the left expression is a subset (not necessarily proper) of the result-set of the right expression.

The two signatures can have different state types, this lets you compare the behaviour of different data structures. The observation and seed types must match, however.

Since: 0.7.0.0

(=>=) :: Ord o => Sig s1 o x -> Sig s2 o x -> RefinementProperty o x #

Infix synonym for refines.

You might think this should be =<=, so it looks kind of like a funny subset operator, with A =<= B meaning "the result-set of A is a subset of the result-set of B". Unfortunately you would be wrong. The operator used in the literature for refinement has the open end pointing at the LESS general term and the closed end at the MORE general term. It is read as "is refined by", not "refines". So for consistency with the literature, the open end of =>= points at the less general term, and the closed end at the more general term, to give the same argument order as refines.

Since: 0.7.0.0

strictlyRefines :: Ord o => Sig s1 o x -> Sig s2 o x -> RefinementProperty o x #

Strict observational refinement.

True iff the result-set of the left expression is a proper subset of the result-set of the right expression.

The two signatures can have different state types, this lets you compare the behaviour of different data structures. The observation and seed types must match, however.

Since: 0.7.0.0

(->-) :: Ord o => Sig s1 o x -> Sig s2 o x -> RefinementProperty o x #

Infix synonym for strictlyRefines

Since: 0.7.0.0

equivalentTo :: Ord o => Sig s1 o x -> Sig s2 o x -> RefinementProperty o x #

Observational equivalence.

True iff the result-set of the left expression is equal to the result-set of the right expression.

The two signatures can have different state types, this lets you compare the behaviour of different data structures. The observation and seed types must match, however.

Since: 0.7.0.0

(===) :: Ord o => Sig s1 o x -> Sig s2 o x -> RefinementProperty o x #

Infix synonym for equivalentTo.

Since: 0.7.0.0

Deprecated

testDejafuDiscard #

Arguments

:: Show b
=> (Either Failure a -> Maybe Discard)	Selectively discard results.
-> Way	How to execute the concurrent program.
-> MemType	The memory model to use for non-synchronised `CRef` operations.
-> String	The name of the test.
-> ProPredicate a b	The predicate to check.
-> ConcIO a	The computation to test.
-> Test

Deprecated: Use testDejafuWithSettings instead

Variant of testDejafuWay which can selectively discard results.

Since: 1.0.0.0

testDejafusDiscard #

Arguments

:: Show b
=> (Either Failure a -> Maybe Discard)	Selectively discard results.
-> Way	How to execute the concurrent program.
-> MemType	The memory model to use for non-synchronised `CRef` operations.
-> [(String, ProPredicate a b)]	The list of predicates (with names) to check.
-> ConcIO a	The computation to test.
-> Test

Deprecated: Use testDejafusWithSettings instead

Variant of testDejafusWay which can selectively discard results, beyond what each predicate already discards.

Since: 1.0.1.0

Orphan instances

Assertable (ConcIO ()) #	Since: 0.3.0.0
Methods assert :: ConcIO () -> Assertion #
Testable (ConcIO ()) #	Since: 0.3.0.0
Methods test :: ConcIO () -> Test #