Test.Validity

To use the Spec functions in this module, you will need TypeApplications.

The most interesting functions in this module for most uses are:

• genValidSpec
• eqSpec
• ordSpec
• producesValidsOnValids
• forAllValid
• shouldBeValid

Writing properties

Cheap generation with shrinking

forAllValid :: (Show a, GenValid a, Testable prop) => (a -> prop) -> Property

Cheap assertions

shouldBeValid :: (Show a, Validity a) => a -> Expectation

shouldBeInvalid :: (Show a, Validity a) => a -> Expectation

Tests for GenValidity instances

genValidSpec :: forall a. (Typeable a, Show a, GenValid a) => Spec

A Spec that specifies that genValid only generates valid data.

In general it is a good idea to add this spec to your test suite if you write a custom implementation of genValid.

Example usage:

genValidSpec @Int

genValidGeneratesValid :: forall a. (Show a, GenValid a) => Property

genValid only generates valid data

genValidGeneratesValid @()

genValidGeneratesValid @Bool

genValidGeneratesValid @Ordering

genValidGeneratesValid @Char

genValidGeneratesValid @Int

genValidGeneratesValid @Float

genValidGeneratesValid @Double

genValidGeneratesValid @Integer

genValidGeneratesValid @(Maybe Int)

genValidGeneratesValid @[Int]

genGeneratesValid :: (Show a, Validity a) => Gen a -> Property

The given generator generates only valid data points

shrinkValidSpec :: forall a. (Show a, Eq a, Typeable a, GenValid a) => Spec

shrinkValidSpecWithLimit :: forall a. (Show a, Eq a, Typeable a, GenValid a) => Int -> Spec

shrinkValidPreservesValidOnGenValid :: forall a. (Show a, GenValid a) => Property

shrinkPreservesValidOnGenValid :: (Show a, GenValid a) => (a -> [a]) -> Property

shrinkPreservesValidOnGenValid ((:[]) :: Int -> [Int])

shrinkValidPreservesValid :: (Show a, GenValid a) => Gen a -> Property

shrinkValidPreservesValid (pure 5 :: Gen Rational)

shrinkingStaysValid :: (Show a, Validity a) => Gen a -> (a -> [a]) -> Property

shrinkingStaysValid (pure 5 :: Gen Double) (\d -> [d - 1, d - 2])

shrinkingPreserves :: Show a => Gen a -> (a -> [a]) -> (a -> Bool) -> Property

shrinkingPreserves (pure 5 :: Gen Int) (:[]) (== 5)

Tests for Arbitrary instances involving Validity

arbitrarySpec :: forall a. (Typeable a, Show a, Validity a, Arbitrary a) => Spec

A Spec that specifies that arbitrary only generates data that satisfy isValid

Example usage:

arbitrarySpec @Int

arbitraryGeneratesOnlyValid :: forall a. (Show a, Validity a, Arbitrary a) => Property

arbitrary only generates valid data

arbitraryGeneratesOnlyValid @Int

Standard tests involving functions

Standard tests involving validity

producesValidsOnGen :: (Show a, Show b, Validity b) => (a -> b) -> Gen a -> (a -> [a]) -> Property

The function produces valid output when the input is generated as specified by the given generator.

producesValid :: (Show a, Show b, GenValid a, Validity b) => (a -> b) -> Property

The function produces valid output when the input is generated by genValid

producesValidsOnArbitrary :: (Show a, Show b, Arbitrary a, Validity b) => (a -> b) -> Property

The function produces valid output when the input is generated by arbitrary

producesValidsOnGens2 :: (Show a, Show b, Show c, Validity c) => (a -> b -> c) -> Gen (a, b) -> ((a, b) -> [(a, b)]) -> Property

producesValid2 :: (Show a, Show b, Show c, GenValid a, GenValid b, Validity c) => (a -> b -> c) -> Property

producesValidsOnArbitrary2 :: (Show a, Show b, Show c, Arbitrary a, Arbitrary b, Validity c) => (a -> b -> c) -> Property

producesValidsOnGens3 :: (Show a, Show b, Show c, Show d, Validity d) => (a -> b -> c -> d) -> Gen (a, b, c) -> ((a, b, c) -> [(a, b, c)]) -> Property

producesValid3 :: (Show a, Show b, Show c, Show d, GenValid a, GenValid b, GenValid c, Validity d) => (a -> b -> c -> d) -> Property

producesValidsOnArbitrary3 :: (Show a, Show b, Show c, Show d, Arbitrary a, Arbitrary b, Arbitrary c, Validity d) => (a -> b -> c -> d) -> Property

Standard tests involving functions that can fail

class CanFail (f :: Type -> Type) where

A class of types that are the result of functions that can fail

Methods

hasFailed :: f a -> Bool

resultIfSucceeded :: f a -> Maybe a

Instances

CanFail Maybe

Defined in Test.Validity.Types

Methods

hasFailed :: Maybe a -> Bool

resultIfSucceeded :: Maybe a -> Maybe a

CanFail (Either e)

Defined in Test.Validity.Types

Methods

hasFailed :: Either e a -> Bool

resultIfSucceeded :: Either e a -> Maybe a

succeedsOnGen :: (Show a, Show (f b), CanFail f) => (a -> f b) -> Gen a -> (a -> [a]) -> Property

The function succeeds if the input is generated by the given generator

succeeds :: (Show a, Show (f b), GenValid a, CanFail f) => (a -> f b) -> Property

The function succeeds if the input is generated by genValid

succeedsOnArbitrary :: (Show a, Show (f b), Arbitrary a, CanFail f) => (a -> f b) -> Property

The function succeeds if the input is generated by arbitrary

succeedsOnGens2 :: (Show a, Show b, Show (f c), CanFail f) => (a -> b -> f c) -> Gen (a, b) -> ((a, b) -> [(a, b)]) -> Property

succeeds2 :: (Show a, Show b, Show (f c), GenValid a, GenValid b, CanFail f) => (a -> b -> f c) -> Property

succeedsOnArbitrary2 :: (Show a, Show b, Show (f c), Arbitrary a, Arbitrary b, CanFail f) => (a -> b -> f c) -> Property

failsOnGen :: (Show a, Show (f b), CanFail f) => (a -> f b) -> Gen a -> (a -> [a]) -> Property

The function fails if the input is generated by the given generator

failsOnGens2 :: (Show a, Show b, Show (f c), CanFail f) => (a -> b -> f c) -> Gen a -> (a -> [a]) -> Gen b -> (b -> [b]) -> Property

validIfSucceedsOnGen :: (Show a, Show b, Validity b, CanFail f) => (a -> f b) -> Gen a -> (a -> [a]) -> Property

The function produces output that satisfies isValid if it is given input that is generated by the given generator.

validIfSucceedsOnArbitrary :: (Show a, Show b, Arbitrary a, Validity b, CanFail f) => (a -> f b) -> Property

The function produces output that satisfies isValid if it is given input that is generated by arbitrary.

validIfSucceeds :: (Show a, Show b, GenValid a, Validity b, CanFail f) => (a -> f b) -> Property

The function produces output that satisfies isValid if it is given input that is generated by genValid.

validIfSucceedsOnGens2 :: (Show a, Show b, Show c, Validity c, CanFail f) => (a -> b -> f c) -> Gen (a, b) -> ((a, b) -> [(a, b)]) -> Property

validIfSucceeds2 :: (Show a, Show b, Show c, GenValid a, GenValid b, Validity c, CanFail f) => (a -> b -> f c) -> Property

validIfSucceedsOnArbitrary2 :: (Show a, Show b, Show c, Arbitrary a, Arbitrary b, Validity c, CanFail f) => (a -> b -> f c) -> Property

validIfSucceedsOnGens3 :: (Show a, Show b, Show c, Show d, Validity d, CanFail f) => (a -> b -> c -> f d) -> Gen (a, b, c) -> ((a, b, c) -> [(a, b, c)]) -> Property

validIfSucceeds3 :: (Show a, Show b, Show c, Show d, GenValid a, GenValid b, GenValid c, Validity d, CanFail f) => (a -> b -> c -> f d) -> Property

validIfSucceedsOnArbitrary3 :: (Show a, Show b, Show c, Show d, Arbitrary a, Arbitrary b, Arbitrary c, Validity d, CanFail f) => (a -> b -> c -> f d) -> Property

Standard tests involving equivalence of functions

Simple functions

One argument

equivalentOnGen :: (Show a, Show b, Eq b) => (a -> b) -> (a -> b) -> Gen a -> (a -> [a]) -> Property

equivalent :: (Show a, GenValid a, Show b, Eq b) => (a -> b) -> (a -> b) -> Property

equivalentOnArbitrary :: (Show a, Arbitrary a, Show b, Eq b) => (a -> b) -> (a -> b) -> Property

equivalentOnArbitrary ((* 2) . (+ 1)) ((+ 2) . (* 2) :: Int -> Int)

Two arguments

equivalentOnGens2 :: (Show a, Show b, Show c, Eq c) => (a -> b -> c) -> (a -> b -> c) -> Gen (a, b) -> ((a, b) -> [(a, b)]) -> Property

equivalent2 :: (Show a, GenValid a, Show b, GenValid b, Show c, Eq c) => (a -> b -> c) -> (a -> b -> c) -> Property

equivalentOnArbitrary2 :: (Show a, Arbitrary a, Show b, Arbitrary b, Show c, Eq c) => (a -> b -> c) -> (a -> b -> c) -> Property

equivalentOnArbitrary2 (+) ((+) :: Int -> Int -> Int)

Three arguments

equivalentOnGens3 :: (Show a, Show b, Show c, Show d, Eq d) => (a -> b -> c -> d) -> (a -> b -> c -> d) -> Gen (a, b, c) -> ((a, b, c) -> [(a, b, c)]) -> Property

equivalent3 :: (Show a, GenValid a, Show b, GenValid b, Show c, GenValid c, Show d, Eq d) => (a -> b -> c -> d) -> (a -> b -> c -> d) -> Property

equivalentOnArbitrary3 :: (Show a, Arbitrary a, Show b, Arbitrary b, Show c, Arbitrary c, Show d, Eq d) => (a -> b -> c -> d) -> (a -> b -> c -> d) -> Property

First function can fail

One argument

equivalentWhenFirstSucceedsOnGen :: (Show a, Show b, Eq b, CanFail f) => (a -> f b) -> (a -> b) -> Gen a -> (a -> [a]) -> Property

equivalentWhenFirstSucceeds :: (Show a, GenValid a, Show b, Eq b, CanFail f) => (a -> f b) -> (a -> b) -> Property

equivalentWhenFirstSucceedsOnArbitrary :: (Show a, Arbitrary a, Show b, Eq b, CanFail f) => (a -> f b) -> (a -> b) -> Property

Two arguments

equivalentWhenFirstSucceedsOnGens2 :: (Show a, Show b, Show c, Eq c, CanFail f) => (a -> b -> f c) -> (a -> b -> c) -> Gen (a, b) -> ((a, b) -> [(a, b)]) -> Property

equivalentWhenFirstSucceeds2 :: (Show a, GenValid a, Show b, GenValid b, Show c, Eq c, CanFail f) => (a -> b -> f c) -> (a -> b -> c) -> Property

equivalentWhenFirstSucceedsOnArbitrary2 :: (Show a, Arbitrary a, Show b, Arbitrary b, Show c, Eq c, CanFail f) => (a -> b -> f c) -> (a -> b -> c) -> Property

Second function can fail

One argument

equivalentWhenSecondSucceedsOnGen :: (Show a, Show b, Eq b, CanFail f) => (a -> b) -> (a -> f b) -> Gen a -> (a -> [a]) -> Property

equivalentWhenSecondSucceeds :: (Show a, GenValid a, Show b, Eq b, CanFail f) => (a -> b) -> (a -> f b) -> Property

equivalentWhenSecondSucceedsOnArbitrary :: (Show a, Arbitrary a, Show b, Eq b, CanFail f) => (a -> b) -> (a -> f b) -> Property

Two arguments

equivalentWhenSecondSucceedsOnGens2 :: (Show a, Show b, Show c, Eq c, CanFail f) => (a -> b -> c) -> (a -> b -> f c) -> Gen (a, b) -> ((a, b) -> [(a, b)]) -> Property

equivalentWhenSecondSucceeds2 :: (Show a, GenValid a, Show b, GenValid b, Show c, Eq c, CanFail f) => (a -> b -> c) -> (a -> b -> f c) -> Property

equivalentWhenSecondSucceedsOnArbitrary2 :: (Show a, Arbitrary a, Show b, Arbitrary b, Show c, Eq c, CanFail f) => (a -> b -> c) -> (a -> b -> f c) -> Property

Both functions can fail

One argument

equivalentWhenSucceedOnGen :: (Show a, Show b, Eq b, CanFail f) => (a -> f b) -> (a -> f b) -> Gen a -> (a -> [a]) -> Property

equivalentWhenSucceed :: (Show a, GenValid a, Show b, Eq b, CanFail f) => (a -> f b) -> (a -> f b) -> Property

equivalentWhenSucceedOnArbitrary :: (Show a, Arbitrary a, Show b, Eq b, CanFail f) => (a -> f b) -> (a -> f b) -> Property

Two arguments

equivalentWhenSucceedOnGens2 :: (Show a, Show b, Show c, Eq c, CanFail f) => (a -> b -> f c) -> (a -> b -> f c) -> Gen (a, b) -> ((a, b) -> [(a, b)]) -> Property

equivalentWhenSucceed2 :: (Show a, GenValid a, Show b, GenValid b, Show c, Eq c, CanFail f) => (a -> b -> f c) -> (a -> b -> f c) -> Property

equivalentWhenSucceedOnArbitrary2 :: (Show a, Arbitrary a, Show b, Arbitrary b, Show c, Eq c, CanFail f) => (a -> b -> f c) -> (a -> b -> f c) -> Property

Standard tests involving inverse functions

inverseFunctionsOnGen :: (Show a, Eq a) => (a -> b) -> (b -> a) -> Gen a -> (a -> [a]) -> Property

inverseFunctions :: (Show a, Eq a, GenValid a) => (a -> b) -> (b -> a) -> Property

inverseFunctionsOnArbitrary :: (Show a, Eq a, Arbitrary a) => (a -> b) -> (b -> a) -> Property

id is its own inverse function for every type: prop> inverseFunctionsOnArbitrary id (id :: Int -> Int)

inverseFunctionsIfFirstSucceedsOnGen :: (Show a, Eq a, CanFail f) => (a -> f b) -> (b -> a) -> Gen a -> (a -> [a]) -> Property

inverseFunctionsIfFirstSucceeds :: (Show a, Eq a, GenValid a, CanFail f) => (a -> f b) -> (b -> a) -> Property

inverseFunctionsIfFirstSucceedsOnArbitrary :: (Show a, Eq a, Arbitrary a, CanFail f) => (a -> f b) -> (b -> a) -> Property

inverseFunctionsIfSecondSucceedsOnGen :: (Show a, Eq a, CanFail f) => (a -> b) -> (b -> f a) -> Gen a -> (a -> [a]) -> Property

inverseFunctionsIfSecondSucceeds :: (Show a, Eq a, GenValid a, CanFail f) => (a -> b) -> (b -> f a) -> Property

inverseFunctionsIfSecondSucceedsOnArbitrary :: (Show a, Eq a, Arbitrary a, CanFail f) => (a -> b) -> (b -> f a) -> Property

inverseFunctionsIfSucceedOnGen :: (Show a, Eq a, CanFail f, CanFail g) => (a -> f b) -> (b -> g a) -> Gen a -> (a -> [a]) -> Property

inverseFunctionsIfSucceed :: (Show a, Eq a, GenValid a, CanFail f, CanFail g) => (a -> f b) -> (b -> g a) -> Property

inverseFunctionsIfSucceedOnArbitrary :: (Show a, Eq a, Arbitrary a, CanFail f, CanFail g) => (a -> f b) -> (b -> g a) -> Property

Properties involving idempotence

idempotentOnGen :: (Show a, Eq a) => (a -> a) -> Gen a -> (a -> [a]) -> Property

idempotent :: (Show a, Eq a, GenValid a) => (a -> a) -> Property

idempotentOnArbitrary :: (Show a, Eq a, Arbitrary a) => (a -> a) -> Property

id is idempotent for any type:

idempotentOnArbitrary (id :: Int -> Int)

const, given any input, is idempotent for any type as well:

\int -> idempotentOnArbitrary (const int :: Int -> Int)

Properties of relations

Reflexivity

reflexiveOnElem

Arguments

:: (a -> a -> Bool)

A relation

-> a

An element

-> Bool

\[ Reflexive(\prec) \quad\equiv\quad \forall a: (a \prec a) \]

reflexivityOnGen :: Show a => (a -> a -> Bool) -> Gen a -> (a -> [a]) -> Property

reflexivity :: (Show a, GenValid a) => (a -> a -> Bool) -> Property

reflexivity ((<=) :: Int -> Int -> Bool)

reflexivity ((==) :: Int -> Int -> Bool)

reflexivity ((>=) :: Int -> Int -> Bool)

reflexivity (Data.List.isPrefixOf :: [Int] -> [Int] -> Bool)

reflexivity (Data.List.isSuffixOf :: [Int] -> [Int] -> Bool)

reflexivity (Data.List.isInfixOf :: [Int] -> [Int] -> Bool)

reflexivityOnArbitrary :: (Show a, Arbitrary a) => (a -> a -> Bool) -> Property

reflexivityOnArbitrary ((<=) :: Int -> Int -> Bool)

reflexivityOnArbitrary ((==) :: Int -> Int -> Bool)

reflexivityOnArbitrary ((>=) :: Int -> Int -> Bool)

reflexivityOnArbitrary (Data.List.isPrefixOf :: [Int] -> [Int] -> Bool)

reflexivityOnArbitrary (Data.List.isSuffixOf :: [Int] -> [Int] -> Bool)

reflexivityOnArbitrary (Data.List.isInfixOf :: [Int] -> [Int] -> Bool)

Transitivity

transitiveOnElems

Arguments

:: (a -> a -> Bool)

A relation

-> a

-> a

-> a

Three elements

-> Bool

\[ Transitive(\prec) \quad\equiv\quad \forall a, b, c: ((a \prec b) \wedge (b \prec c)) \Rightarrow (a \prec c) \]

transitivityOnGens :: Show a => (a -> a -> Bool) -> Gen (a, a, a) -> (a -> [a]) -> Property

transitivity :: (Show a, GenValid a) => (a -> a -> Bool) -> Property

transitivity ((>) :: Int -> Int -> Bool)

transitivity ((>=) :: Int -> Int -> Bool)

transitivity ((==) :: Int -> Int -> Bool)

transitivity ((<=) :: Int -> Int -> Bool)

transitivity ((<) :: Int -> Int -> Bool)

transitivity (Data.List.isPrefixOf :: [Int] -> [Int] -> Bool)

transitivity (Data.List.isSuffixOf :: [Int] -> [Int] -> Bool)

transitivity (Data.List.isInfixOf :: [Int] -> [Int] -> Bool)

transitivityOnArbitrary :: (Show a, Arbitrary a) => (a -> a -> Bool) -> Property

transitivityOnArbitrary ((>) :: Int -> Int -> Bool)

transitivityOnArbitrary ((>=) :: Int -> Int -> Bool)

transitivityOnArbitrary ((==) :: Int -> Int -> Bool)

transitivityOnArbitrary ((<=) :: Int -> Int -> Bool)

transitivityOnArbitrary ((<) :: Int -> Int -> Bool)

transitivityOnArbitrary (Data.List.isPrefixOf :: [Int] -> [Int] -> Bool)

transitivityOnArbitrary (Data.List.isSuffixOf :: [Int] -> [Int] -> Bool)

transitivityOnArbitrary (Data.List.isInfixOf :: [Int] -> [Int] -> Bool)

Antisymmetry

antisymmetricOnElemsWithEquality

Arguments

:: (a -> a -> Bool)

A relation

-> (a -> a -> Bool)

An equivalence relation

-> a

-> a

Two elements

-> Bool

\[ Antisymmetric(\prec, \doteq) \quad\equiv\quad \forall a, b: ((a \prec b) \wedge (b \prec a)) \Rightarrow (a \doteq b) \]

antisymmetryOnGensWithEquality :: Show a => (a -> a -> Bool) -> Gen (a, a) -> (a -> a -> Bool) -> (a -> [a]) -> Property

antisymmetryOnGens :: (Show a, Eq a) => (a -> a -> Bool) -> Gen (a, a) -> (a -> [a]) -> Property

antisymmetry :: (Show a, Eq a, GenValid a) => (a -> a -> Bool) -> Property

antisymmetry ((>) :: Int -> Int -> Bool)

antisymmetry ((>=) :: Int -> Int -> Bool)

antisymmetry ((<=) :: Int -> Int -> Bool)

antisymmetry ((<) :: Int -> Int -> Bool)

antisymmetry (Data.List.isPrefixOf :: [Int] -> [Int] -> Bool)

antisymmetry (Data.List.isSuffixOf :: [Int] -> [Int] -> Bool)

antisymmetry (Data.List.isInfixOf :: [Int] -> [Int] -> Bool)

antisymmetry ((\x y -> even x && odd y) :: Int -> Int -> Bool)

antisymmetryOnArbitrary :: (Show a, Eq a, Arbitrary a) => (a -> a -> Bool) -> Property

antisymmetryOnArbitrary ((>) :: Int -> Int -> Bool)

antisymmetryOnArbitrary ((>=) :: Int -> Int -> Bool)

antisymmetryOnArbitrary ((<=) :: Int -> Int -> Bool)

antisymmetryOnArbitrary ((<) :: Int -> Int -> Bool)

antisymmetryOnArbitrary (Data.List.isPrefixOf :: [Int] -> [Int] -> Bool)

antisymmetryOnArbitrary (Data.List.isSuffixOf :: [Int] -> [Int] -> Bool)

antisymmetryOnArbitrary (Data.List.isInfixOf :: [Int] -> [Int] -> Bool)

antisymmetryOnArbitrary ((\x y -> even x && odd y) :: Int -> Int -> Bool)

Antireflexivity

antireflexiveOnElem

Arguments

:: (a -> a -> Bool)

A relation

-> a

An element

-> Bool

\[ Antireflexive(\prec) \quad\equiv\quad \forall a: \neg (a \prec a) \]

antireflexivityOnGen :: Show a => (a -> a -> Bool) -> Gen a -> (a -> [a]) -> Property

antireflexivity :: (Show a, GenValid a) => (a -> a -> Bool) -> Property

antireflexivity ((<) :: Int -> Int -> Bool)

antireflexivity ((/=) :: Int -> Int -> Bool)

antireflexivity ((>) :: Int -> Int -> Bool)

antireflexivityOnArbitrary :: (Show a, Arbitrary a) => (a -> a -> Bool) -> Property

antireflexivityOnArbitrary ((<) :: Int -> Int -> Bool)

antireflexivityOnArbitrary ((/=) :: Int -> Int -> Bool)

antireflexivityOnArbitrary ((>) :: Int -> Int -> Bool)

Symmetry

symmetricOnElems

Arguments

:: (a -> a -> Bool)

A relation

-> a

-> a

Two elements

-> Bool

\[ Symmetric(\prec) \quad\equiv\quad \forall a, b: (a \prec b) \Leftrightarrow (b \prec a) \]

symmetryOnGens :: Show a => (a -> a -> Bool) -> Gen (a, a) -> (a -> [a]) -> Property

symmetry :: (Show a, GenValid a) => (a -> a -> Bool) -> Property

symmetry ((==) :: Int -> Int -> Bool)

symmetry ((/=) :: Int -> Int -> Bool)

symmetryOnArbitrary :: (Show a, Arbitrary a) => (a -> a -> Bool) -> Property

symmetryOnArbitrary ((==) :: Int -> Int -> Bool)

symmetryOnArbitrary ((/=) :: Int -> Int -> Bool)

Properties of operations

Identity element

Left Identity

leftIdentityOnElemWithEquality

Arguments

:: (b -> a -> a)

A binary operation

-> (a -> a -> Bool)

An equality

-> b

A candidate left-identity

-> a

An element

-> Bool

\[ LeftIdentity(\star, \doteq, b) \quad\equiv\quad \forall a: (b \star a) \doteq a \]

leftIdentityOnGenWithEquality

Arguments

:: Show a

=> (b -> a -> a)

A binary operation

-> (a -> a -> Bool)

An equality

-> b

A candidate left-identity

-> Gen a

-> (a -> [a])

-> Property

leftIdentityOnGen

Arguments

:: (Show a, Eq a)

=> (b -> a -> a)

A binary operation

-> b

A candidate left-identity

-> Gen a

-> (a -> [a])

-> Property

leftIdentity :: (Show a, Eq a, GenValid a) => (b -> a -> a) -> b -> Property

leftIdentity (flip ((^) :: Int -> Int -> Int)) 1

leftIdentityOnArbitrary :: (Show a, Eq a, Arbitrary a) => (b -> a -> a) -> b -> Property

leftIdentityOnArbitrary (flip ((^) :: Int -> Int -> Int)) 1

Right Identity

rightIdentityOnElemWithEquality

Arguments

:: (a -> b -> a)

A binary operation

-> (a -> a -> Bool)

An equality

-> b

A candidate right-identity

-> a

An element

-> Bool

\[ RightIdentity(\star, \doteq, b) \quad\equiv\quad \forall a: (a \star b) \doteq a \]

rightIdentityOnGenWithEquality

Arguments

:: Show a

=> (a -> b -> a)

A binary operation

-> (a -> a -> Bool)

An equality

-> b

A candidate right-identity

-> Gen a

-> (a -> [a])

-> Property

rightIdentityOnGen

Arguments

:: (Show a, Eq a)

=> (a -> b -> a)

A binary operation

-> b

A candidate right-identity

-> Gen a

-> (a -> [a])

-> Property

rightIdentity :: (Show a, Eq a, GenValid a) => (a -> b -> a) -> b -> Property

rightIdentity ((^) :: Int -> Int -> Int) 1

rightIdentityOnArbitrary :: (Show a, Eq a, Arbitrary a) => (a -> b -> a) -> b -> Property

rightIdentityOnArbitrary ((^) :: Int -> Int -> Int) 1

Identity

identityOnGen :: (Show a, Eq a) => (a -> a -> a) -> a -> Gen a -> (a -> [a]) -> Property

\[ Identity(\star, \doteq, b) \quad\equiv\quad LeftIdentity(\star, \doteq, b) \wedge RightIdentity(\star, \doteq, b) \]

identity :: (Show a, Eq a, GenValid a) => (a -> a -> a) -> a -> Property

identity ((*) :: Int -> Int -> Int) 1

identity ((+) :: Int -> Int -> Int) 0

identityOnArbitrary :: (Show a, Eq a, Arbitrary a) => (a -> a -> a) -> a -> Property

identityOnArbitrary ((*) :: Int -> Int -> Int) 1

identityOnArbitrary ((+) :: Int -> Int -> Int) 0

Associativity

associativeOnGens :: (Show a, Eq a) => (a -> a -> a) -> Gen (a, a, a) -> ((a, a, a) -> [(a, a, a)]) -> Property

\[ Associative(\star) \quad\equiv\quad \forall a, b, c: (a \star b) \star c = a \star (b \star c) \]

associative :: (Show a, Eq a, GenValid a) => (a -> a -> a) -> Property

associative ((*) :: Int -> Int -> Int)

associative ((+) :: Int -> Int -> Int)

associativeOnArbitrary :: (Show a, Eq a, Arbitrary a) => (a -> a -> a) -> Property

associativeOnArbitrary ((*) :: Int -> Int -> Int)

associativeOnArbitrary ((+) :: Int -> Int -> Int)

Commutativity

commutativeOnGens :: (Show a, Show b, Eq b) => (a -> a -> b) -> Gen (a, a) -> ((a, a) -> [(a, a)]) -> Property

\[ Commutative(\star) \quad\equiv\quad \forall a, b: a \star b = b \star a \]

commutative :: (Show a, Show b, Eq b, GenValid a) => (a -> a -> b) -> Property

commutative ((+) :: Int -> Int -> Int)

commutative ((*) :: Int -> Int -> Int)

commutativeOnArbitrary :: (Show a, Show b, Eq b, Arbitrary a) => (a -> a -> b) -> Property

commutativeOnArbitrary ((+) :: Int -> Int -> Int)

commutativeOnArbitrary ((*) :: Int -> Int -> Int)

commutativeOnArbitrary :: (Show a, Eq a, Arbitrary a) => (a -> a -> a) -> Property

Show and Read properties

showReadSpec :: forall a. (Show a, Eq a, Read a, Typeable a, GenValid a) => Spec

Standard test spec for properties of Show and Read instances for valid values

Example usage:

showReadSpec @Int

showReadSpecOnArbitrary :: forall a. (Show a, Eq a, Read a, Typeable a, Arbitrary a) => Spec

Standard test spec for properties of Show and Read instances for arbitrary values

Example usage:

showReadSpecOnArbitrary @Double

showReadSpecOnGen :: forall a. (Show a, Eq a, Read a, Typeable a) => Gen a -> String -> (a -> [a]) -> Spec

Standard test spec for properties of Show and Read instances for values generated by a custom generator

Example usage:

showReadSpecOnGen ((* 2) <$> genValid @Int) "even" (const [])

Eq properties

eqSpec :: forall a. (Show a, Eq a, Typeable a, GenValid a) => Spec

Standard test spec for properties of Eq instances for valid values

Example usage:

eqSpec @Int

eqSpecOnArbitrary :: forall a. (Show a, Eq a, Typeable a, Arbitrary a) => Spec

Standard test spec for properties of Eq instances for arbitrary values

Example usage:

eqSpecOnArbitrary @Int

eqSpecOnGen :: forall a. (Show a, Eq a, Typeable a) => Gen a -> String -> (a -> [a]) -> Spec

Standard test spec for properties of Eq instances for values generated by a given generator (and name for that generator).

Example usage:

eqSpecOnGen ((* 2) <$> genValid @Int) "even"

Ord properties

ordSpecOnGen :: forall a. (Show a, Ord a, Typeable a) => Gen a -> String -> (a -> [a]) -> Spec

Standard test spec for properties of Ord instances for values generated by a given generator (and name for that generator).

Example usage:

ordSpecOnGen ((* 2) <$> genValid @Int) "even"

ordSpec :: forall a. (Show a, Ord a, Typeable a, GenValid a) => Spec

Standard test spec for properties of Ord instances for valid values

Example usage:

ordSpec @Int

ordSpecOnArbitrary :: forall a. (Show a, Ord a, Typeable a, Arbitrary a) => Spec

Standard test spec for properties of Ord instances for arbitrary values

Example usage:

ordSpecOnArbitrary @Int

Monoid properties

monoidSpec :: forall a. (Show a, Eq a, Monoid a, Typeable a, GenValid a) => Spec

Standard test spec for properties of Monoid instances for valid values

Example usage:

monoidSpec @[Int]

monoidSpecOnArbitrary :: forall a. (Show a, Eq a, Monoid a, Typeable a, Arbitrary a) => Spec

Standard test spec for properties of Monoid instances for arbitrary values

Example usage:

monoidSpecOnArbitrary @[Int]

monoidSpecOnGen :: forall a. (Show a, Eq a, Monoid a, Typeable a) => Gen a -> String -> (a -> [a]) -> Spec

Standard test spec for properties of Monoid instances for values generated by a given generator (and name for that generator).

Example usage:

monoidSpecOnGen (pure "a") "singleton list of 'a'"

Functor properties

functorSpec :: forall (f :: Type -> Type). (Eq (f Int), Show (f Int), Functor f, Typeable f, GenValid (f Int)) => Spec

Standard test spec for properties of Functor instances for values generated with GenValid instances

Example usage:

functorSpecOnArbitrary @[]

functorSpecOnArbitrary :: forall (f :: Type -> Type). (Eq (f Int), Show (f Int), Functor f, Typeable f, Arbitrary (f Int)) => Spec

Standard test spec for properties of Functor instances for values generated with Arbitrary instances

Example usage:

functorSpecOnArbitrary @[]

functorSpecOnGens :: forall (f :: Type -> Type) (a :: Type) (b :: Type) (c :: Type). (Show a, Show (f a), Show (f c), Eq (f a), Eq (f c), Functor f, Typeable f, Typeable a, Typeable b, Typeable c) => Gen a -> String -> Gen (f a) -> String -> Gen (b -> c) -> String -> Gen (a -> b) -> String -> Spec

Standard test spec for properties of Functor instances for values generated by given generators (and names for those generator).

Example usage:

functorSpecOnGens
    @[]
    @Int
    (pure 4) "four"
    (genListOf $ pure 5) "list of fives"
    ((+) <$> genValid) "additions"
    ((*) <$> genValid) "multiplications"

Applicative properties

applicativeSpec :: forall (f :: Type -> Type). (Eq (f Int), Show (f Int), Applicative f, Typeable f, GenValid (f Int)) => Spec

Standard test spec for properties of Applicative instances for values generated with GenValid instances

Example usage:

applicativeSpecOnArbitrary @[]

applicativeSpecOnArbitrary :: forall (f :: Type -> Type). (Eq (f Int), Show (f Int), Applicative f, Typeable f, Arbitrary (f Int)) => Spec

Standard test spec for properties of Applicative instances for values generated with Arbitrary instances

Example usage:

applicativeSpecOnArbitrary @[]

applicativeSpecOnGens :: forall (f :: Type -> Type) (a :: Type) (b :: Type) (c :: Type). (Show a, Show (f a), Eq (f a), Show (f b), Eq (f b), Show (f c), Eq (f c), Applicative f, Typeable f, Typeable a, Typeable b, Typeable c) => Gen a -> String -> Gen (f a) -> String -> Gen (f b) -> String -> Gen (a -> b) -> String -> Gen (f (a -> b)) -> String -> Gen (f (b -> c)) -> String -> Spec

Standard test spec for properties of Applicative instances for values generated by given generators (and names for those generator).

Unless you are building a specific regression test, you probably want to use the other applicativeSpec functions.

Example usage:

applicativeSpecOnGens
    @Maybe
    @String
    (pure "ABC")
    "ABC"
    (Just <$> pure "ABC")
    "Just an ABC"
    (pure Nothing)
    "purely Nothing"
    ((++) <$> genValid)
    "prepends"
    (pure <$> ((++) <$> genValid))
    "prepends in a Just"
    (pure <$> (flip (++) <$> genValid))
    "appends in a Just"

Monad properties

monadSpec :: forall (f :: Type -> Type). (Eq (f Int), Show (f Int), Monad f, Typeable f, GenValid (f Int)) => Spec

Standard test spec for properties of Monad instances for values generated with GenValid instances

Example usage:

monadSpec @[]

monadSpecOnArbitrary :: forall (f :: Type -> Type). (Eq (f Int), Show (f Int), Monad f, Typeable f, Arbitrary (f Int)) => Spec

Standard test spec for properties of Monad instances for values generated with Arbitrary instances

Example usage:

monadSpecOnArbitrary @[]

monadSpecOnGens :: forall (f :: Type -> Type) (a :: Type) (b :: Type) (c :: Type). (Show a, Show (f a), Show (f b), Show (f c), Eq (f a), Eq (f b), Eq (f c), Monad f, Typeable f, Typeable a, Typeable b, Typeable c) => Gen a -> String -> Gen (f a) -> String -> Gen (f b) -> String -> Gen (a -> b) -> String -> Gen (a -> f b) -> String -> Gen (b -> f c) -> String -> Gen (f (a -> b)) -> String -> Spec

Standard test spec for properties of Monad instances for values generated by given generators (and names for those generator).

Example usage:

monadSpecOnGens
    @[]
    @Int
    (pure 4)
    "four"
    (genListOf $ pure 5)
    "list of fives"
    (genListOf $ pure 6)
    "list of sixes"
    ((*) <$> genValid)
    "factorisations"
    (pure $ \a -> [a])
    "singletonisation"
    (pure $ \a -> [a])
    "singletonisation"
    (pure $ pure (+ 1))
    "increment in list"

Re-exports

module Data.GenValidity