| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Data.GenValidity
Description
GenValidity exists to make tests involving Validity types easier and speed
up the generation of data for them.
Let's use the example from Data.Validity again: A datatype that represents
primes.
To implement tests for this datatype, we would have to be able to generate
both primes and non-primes. We could do this with
(Prime $ arbitrary)
but this is tedious and inefficient.suchThat isValid
The GenValid type class allows you to specify how to (efficiently)
generate valid data of the given type to allow for easier and quicker testing.
Just instantiating GenUnchecked already gives you access to a default instance
of GenValid and GenInvalid but writing custom implementations of these functions
may speed up the generation of data.
For example, to generate primes, we don't have to consider even numbers other than 2. A more efficient implementation could then look as follows:
instance GenUnchecked Prime where
genUnchecked = Prime <$> arbitraryinstance GenValid Prime where
genValid = Prime <$>
(oneof
[ pure 2
, ((\y -> 2 * abs y + 1) <$> arbitrary) `suchThat` isPrime)
])Typical examples of tests involving validity could look as follows:
it "succeeds when given valid input" $ do
forAllValid $ \input ->
myFunction input `shouldSatisfy` isRightit "produces valid output when it succeeds" $ do
forAllUnchecked $ \input ->
case myFunction input of
Nothing -> return () -- Can happen
Just output -> output `shouldSatisfy` isValidSynopsis
- module Data.Validity
- class GUncheckedSubtermsIncl f a where
- class GUncheckedSubterms f a where
- class GUncheckedRecursivelyShrink f where
- class GGenUnchecked f where
- class (Validity a, GenUnchecked a) => GenInvalid a where
- class (Validity a, GenUnchecked a) => GenValid a where
- class GenUnchecked a where
- shrinkT2 :: (a -> [a]) -> (a, a) -> [(a, a)]
- shrinkT3 :: (a -> [a]) -> (a, a, a) -> [(a, a, a)]
- upTo :: Int -> Gen Int
- genSplit :: Int -> Gen (Int, Int)
- genSplit3 :: Int -> Gen (Int, Int, Int)
- genSplit4 :: Int -> Gen (Int, Int, Int, Int)
- genSplit5 :: Int -> Gen (Int, Int, Int, Int, Int)
- arbPartition :: Int -> Gen [Int]
- genListOf :: Gen a -> Gen [a]
- gShrinkUnchecked :: (Generic a, GUncheckedRecursivelyShrink (Rep a), GUncheckedSubterms (Rep a) a) => a -> [a]
- uncheckedRecursivelyShrink :: (Generic a, GUncheckedRecursivelyShrink (Rep a)) => a -> [a]
- uncheckedSubterms :: (Generic a, GUncheckedSubterms (Rep a) a) => a -> [a]
Documentation
module Data.Validity
class GUncheckedSubtermsIncl f a where #
Minimal complete definition
Methods
gUncheckedSubtermsIncl :: f a -> [a] #
Instances
| GUncheckedSubtermsIncl (V1 :: * -> *) a # | |
Defined in Data.GenValidity Methods gUncheckedSubtermsIncl :: V1 a -> [a] # | |
| GUncheckedSubtermsIncl (U1 :: * -> *) a # | |
Defined in Data.GenValidity Methods gUncheckedSubtermsIncl :: U1 a -> [a] # | |
| GUncheckedSubtermsIncl (K1 i a :: * -> *) b # | |
Defined in Data.GenValidity Methods gUncheckedSubtermsIncl :: K1 i a b -> [b] # | |
| GUncheckedSubtermsIncl (K1 i a :: * -> *) a # | |
Defined in Data.GenValidity Methods gUncheckedSubtermsIncl :: K1 i a a -> [a] # | |
| (GUncheckedSubtermsIncl f a, GUncheckedSubtermsIncl g a) => GUncheckedSubtermsIncl (f :+: g) a # | |
Defined in Data.GenValidity Methods gUncheckedSubtermsIncl :: (f :+: g) a -> [a] # | |
| (GUncheckedSubtermsIncl f a, GUncheckedSubtermsIncl g a) => GUncheckedSubtermsIncl (f :*: g) a # | |
Defined in Data.GenValidity Methods gUncheckedSubtermsIncl :: (f :*: g) a -> [a] # | |
| GUncheckedSubtermsIncl f a => GUncheckedSubtermsIncl (M1 i c f) a # | |
Defined in Data.GenValidity Methods gUncheckedSubtermsIncl :: M1 i c f a -> [a] # | |
class GUncheckedSubterms f a where #
Minimal complete definition
Methods
gUncheckedSubterms :: f a -> [a] #
Instances
| GUncheckedSubterms (V1 :: * -> *) a # | |
Defined in Data.GenValidity Methods gUncheckedSubterms :: V1 a -> [a] # | |
| GUncheckedSubterms (U1 :: * -> *) a # | |
Defined in Data.GenValidity Methods gUncheckedSubterms :: U1 a -> [a] # | |
| GUncheckedSubterms (K1 i a :: * -> *) b # | |
Defined in Data.GenValidity Methods gUncheckedSubterms :: K1 i a b -> [b] # | |
| (GUncheckedSubtermsIncl f a, GUncheckedSubtermsIncl g a) => GUncheckedSubterms (f :+: g) a # | |
Defined in Data.GenValidity Methods gUncheckedSubterms :: (f :+: g) a -> [a] # | |
| (GUncheckedSubtermsIncl f a, GUncheckedSubtermsIncl g a) => GUncheckedSubterms (f :*: g) a # | |
Defined in Data.GenValidity Methods gUncheckedSubterms :: (f :*: g) a -> [a] # | |
| GUncheckedSubterms f a => GUncheckedSubterms (M1 i c f) a # | |
Defined in Data.GenValidity Methods gUncheckedSubterms :: M1 i c f a -> [a] # | |
class GUncheckedRecursivelyShrink f where #
Minimal complete definition
Methods
gUncheckedRecursivelyShrink :: f a -> [f a] #
Instances
| GUncheckedRecursivelyShrink (V1 :: * -> *) # | |
Defined in Data.GenValidity Methods gUncheckedRecursivelyShrink :: V1 a -> [V1 a] # | |
| GUncheckedRecursivelyShrink (U1 :: * -> *) # | |
Defined in Data.GenValidity Methods gUncheckedRecursivelyShrink :: U1 a -> [U1 a] # | |
| GenUnchecked a => GUncheckedRecursivelyShrink (K1 i a :: * -> *) # | |
Defined in Data.GenValidity Methods gUncheckedRecursivelyShrink :: K1 i a a0 -> [K1 i a a0] # | |
| (GUncheckedRecursivelyShrink f, GUncheckedRecursivelyShrink g) => GUncheckedRecursivelyShrink (f :+: g) # | |
Defined in Data.GenValidity Methods gUncheckedRecursivelyShrink :: (f :+: g) a -> [(f :+: g) a] # | |
| (GUncheckedRecursivelyShrink f, GUncheckedRecursivelyShrink g) => GUncheckedRecursivelyShrink (f :*: g) # | |
Defined in Data.GenValidity Methods gUncheckedRecursivelyShrink :: (f :*: g) a -> [(f :*: g) a] # | |
| GUncheckedRecursivelyShrink f => GUncheckedRecursivelyShrink (M1 i c f) # | |
Defined in Data.GenValidity Methods gUncheckedRecursivelyShrink :: M1 i c f a -> [M1 i c f a] # | |
class GGenUnchecked f where #
Minimal complete definition
Methods
gGenUnchecked :: Gen (f a) #
Instances
| GGenUnchecked (U1 :: * -> *) # | |
Defined in Data.GenValidity Methods gGenUnchecked :: Gen (U1 a) # | |
| GenUnchecked a => GGenUnchecked (K1 i a :: * -> *) # | |
Defined in Data.GenValidity Methods gGenUnchecked :: Gen (K1 i a a0) # | |
| (GGenUnchecked a, GGenUnchecked b) => GGenUnchecked (a :+: b) # | |
Defined in Data.GenValidity Methods gGenUnchecked :: Gen ((a :+: b) a0) # | |
| (GGenUnchecked a, GGenUnchecked b) => GGenUnchecked (a :*: b) # | |
Defined in Data.GenValidity Methods gGenUnchecked :: Gen ((a :*: b) a0) # | |
| GGenUnchecked a => GGenUnchecked (M1 i c a) # | |
Defined in Data.GenValidity Methods gGenUnchecked :: Gen (M1 i c a a0) # | |
class (Validity a, GenUnchecked a) => GenInvalid a where #
A class of types for which invalid values can be generated.
Instances
| GenInvalid Double # | Either |
Defined in Data.GenValidity | |
| GenInvalid Float # | Either |
Defined in Data.GenValidity | |
| GenInvalid a => GenInvalid [a] # | This instance ensures that the generated list contains at least one element
that satisfies |
Defined in Data.GenValidity | |
| GenInvalid a => GenInvalid (Maybe a) # | |
Defined in Data.GenValidity | |
| (Integral a, Num a, Ord a, GenValid a) => GenInvalid (Ratio a) # | |
Defined in Data.GenValidity | |
| GenInvalid a => GenInvalid (NonEmpty a) # | |
Defined in Data.GenValidity | |
| (GenInvalid a, GenInvalid b) => GenInvalid (Either a b) # | This instance ensures that the generated tupse contains at least one invalid element. The other element is unchecked. |
Defined in Data.GenValidity | |
| (GenInvalid a, GenInvalid b) => GenInvalid (a, b) # | |
Defined in Data.GenValidity | |
| (GenInvalid a, GenInvalid b, GenInvalid c) => GenInvalid (a, b, c) # | This instance ensures that the generated triple contains at least one invalid element. The other two are unchecked. |
Defined in Data.GenValidity | |
| (GenInvalid a, GenInvalid b, GenInvalid c, GenInvalid d) => GenInvalid (a, b, c, d) # | This instance ensures that the generated triple contains at least one invalid element. The other two are unchecked. |
Defined in Data.GenValidity | |
| (GenInvalid a, GenInvalid b, GenInvalid c, GenInvalid d, GenInvalid e) => GenInvalid (a, b, c, d, e) # | This instance ensures that the generated triple contains at least one invalid element. The other two are unchecked. |
Defined in Data.GenValidity | |
class (Validity a, GenUnchecked a) => GenValid a where #
A class of types for which valid values can be generated.
If you also write Arbitrary instances for GenValid types, it may be
best to simply write arbitrary = genValid.
Instances
class GenUnchecked a where #
A class of types for which truly arbitrary values can be generated.
Automatic instances with Generic
An instance of this class can be made automatically if the type in question
has a Generic instance. This instance will try to use genUnchecked to
generate all structural sub-parts of the value that is being generated.
Example:
{-# LANGUAGE DeriveGeneric #-}
data MyType = MyType Double String
deriving (Show, Eq, Generic)
instance GenUnchecked MyTypegenerates something like:
instance GenUnchecked MyType where
genUnchecked = MyType <$> genUnchecked <*> genUncheckedMethods
genUnchecked :: Gen a #
genUnchecked :: (Generic a, GGenUnchecked (Rep a)) => Gen a #
shrinkUnchecked :: a -> [a] #
shrinkUnchecked :: (Generic a, GUncheckedRecursivelyShrink (Rep a), GUncheckedSubterms (Rep a) a) => a -> [a] #
Instances
genSplit :: Int -> Gen (Int, Int) #
'genSplit a' generates a tuple '(b, c)' such that 'b + c' equals a.
genSplit3 :: Int -> Gen (Int, Int, Int) #
'genSplit3 a' generates a triple '(b, c, d)' such that 'b + c + d' equals a.
genSplit4 :: Int -> Gen (Int, Int, Int, Int) #
'genSplit4 a' generates a quadruple '(b, c, d, e)' such that 'b + c + d + e' equals a.
genSplit5 :: Int -> Gen (Int, Int, Int, Int, Int) #
'genSplit5 a' generates a quadruple '(b, c, d, e, f)' such that 'b + c + d + e + f' equals a.
arbPartition :: Int -> Gen [Int] #
'arbPartition n' generates a list ls such that 'sum ls' equals n.
gShrinkUnchecked :: (Generic a, GUncheckedRecursivelyShrink (Rep a), GUncheckedSubterms (Rep a) a) => a -> [a] #
Shrink a term to any of its immediate subterms, and also recursively shrink all subterms.
uncheckedRecursivelyShrink :: (Generic a, GUncheckedRecursivelyShrink (Rep a)) => a -> [a] #
Recursively shrink all immediate uncheckedSubterms.
uncheckedSubterms :: (Generic a, GUncheckedSubterms (Rep a) a) => a -> [a] #
All immediate uncheckedSubterms of a term.