Test.Aeson.GenericSpecs

Arbitrary testing

goldenSpecs :: (Eq a, Show a, Typeable a, Arbitrary a, ToJSON a, FromJSON a) => Int -> Proxy a -> Spec

Allows to obtain tests that will try to ensure that the JSON encoding didn't change unintentionally. To this end goldenSpecs will

• write a file golden.json/TYPENAME.json in the current directory containing a number of JSON-encoded sample values,
• during subsequent tests it will encode the same sample values again and compare them with the saved golden encodings,
• on failure it will create a file golden.json/TYPENAME.faulty.json for easy manual inspection.

You can consider putting the golden files under revision control. That way it'll be obvious when JSON encodings change.

roundtripSpecs :: forall a. (Typeable a, Eq a, Show a, Arbitrary a, ToJSON a, FromJSON a) => Proxy a -> Spec

Allows to obtain a roundtrip test to check whether values of the given type can be successfully converted to JSON and back.

roundtripSpecs will

• create random values (using Arbitrary),
• convert them into JSON (using ToJSON),
• read them back into Haskell (using FromJSON) and
• make sure that the result is the same as the value it started with (using Eq).

roundtripAndGoldenSpecs :: forall a. (Arbitrary a, Eq a, Show a, ToJSON a, FromJSON a, Typeable a) => Int -> Proxy a -> Spec

run roundtrip and golden test for a type. sampleSize is used only when creating the golden file. When it is compared, the sampleSize is derived from the file.

ToADTArbitrary testing

goldenADTSpecs :: forall a. (ToADTArbitrary a, Eq a, Show a, Arbitrary a, ToJSON a, FromJSON a) => Int -> Proxy a -> Spec

for a type a, create a set of golden files if they do not exist, compare with golden file if it exists. Golden file encodes json format of a type

roundtripADTSpecs :: forall a. (ToADTArbitrary a, Eq a, Show a, Arbitrary a, ToJSON a, FromJSON a) => Proxy a -> Spec

A roundtrip test to check whether values of the given type can be successfully converted to JSON and back to a Haskell value.

roundtripSpecs will

• create random values using Arbitrary,
• convert them into JSON using ToJSON,
• read them back into Haskell using FromJSON and
• make sure that the result is the same as the value it started with using Eq.

roundtripAndGoldenADTSpecs :: forall a. (Arbitrary a, ToADTArbitrary a, Eq a, Show a, ToJSON a, FromJSON a) => Int -> Proxy a -> Spec

run roundtrip and golden tests for all constructors of a type. sampleSize is used only when creating the golden files. When they are compared, the sampleSize is derived from the file.

shouldBeIdentity :: (Eq a, Show a, Arbitrary a) => Proxy a -> (a -> IO a) -> Property

hspec style combinator to easily write tests that check the a given operation returns the same value it was given, e.g. roundtrip tests.

re-exports

data Proxy k t :: forall k. k -> *

A concrete, poly-kinded proxy type

Constructors

Proxy

Instances

Monad (Proxy *)

Methods

(>>=) :: Proxy * a -> (a -> Proxy * b) -> Proxy * b

(>>) :: Proxy * a -> Proxy * b -> Proxy * b

return :: a -> Proxy * a

fail :: String -> Proxy * a

Functor (Proxy *)

Methods

fmap :: (a -> b) -> Proxy * a -> Proxy * b

(<$) :: a -> Proxy * b -> Proxy * a

Applicative (Proxy *)

Methods

pure :: a -> Proxy * a

(<*>) :: Proxy * (a -> b) -> Proxy * a -> Proxy * b

(*>) :: Proxy * a -> Proxy * b -> Proxy * b

(<*) :: Proxy * a -> Proxy * b -> Proxy * a

Foldable (Proxy *)

Methods

fold :: Monoid m => Proxy * m -> m

foldMap :: Monoid m => (a -> m) -> Proxy * a -> m

foldr :: (a -> b -> b) -> b -> Proxy * a -> b

foldr' :: (a -> b -> b) -> b -> Proxy * a -> b

foldl :: (b -> a -> b) -> b -> Proxy * a -> b

foldl' :: (b -> a -> b) -> b -> Proxy * a -> b

foldr1 :: (a -> a -> a) -> Proxy * a -> a

foldl1 :: (a -> a -> a) -> Proxy * a -> a

toList :: Proxy * a -> [a]

null :: Proxy * a -> Bool

length :: Proxy * a -> Int

elem :: Eq a => a -> Proxy * a -> Bool

maximum :: Ord a => Proxy * a -> a

minimum :: Ord a => Proxy * a -> a

sum :: Num a => Proxy * a -> a

product :: Num a => Proxy * a -> a

Generic1 (Proxy *)

Associated Types

type Rep1 (Proxy * :: * -> *) :: * -> *

Methods

from1 :: Proxy * a -> Rep1 (Proxy *) a

to1 :: Rep1 (Proxy *) a -> Proxy * a

Alternative (Proxy *)

Methods

empty :: Proxy * a

(<|>) :: Proxy * a -> Proxy * a -> Proxy * a

some :: Proxy * a -> Proxy * [a]

many :: Proxy * a -> Proxy * [a]

MonadPlus (Proxy *)

Methods

mzero :: Proxy * a

mplus :: Proxy * a -> Proxy * a -> Proxy * a

Eq1 (Proxy *)

Since: 4.9.0.0

Methods

liftEq :: (a -> b -> Bool) -> Proxy * a -> Proxy * b -> Bool

Ord1 (Proxy *)

Since: 4.9.0.0

Methods

liftCompare :: (a -> b -> Ordering) -> Proxy * a -> Proxy * b -> Ordering

Read1 (Proxy *)

Since: 4.9.0.0

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Proxy * a)

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Proxy * a]

Show1 (Proxy *)

Since: 4.9.0.0

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Proxy * a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Proxy * a] -> ShowS

Bounded (Proxy k s)

Methods

minBound :: Proxy k s

maxBound :: Proxy k s

Enum (Proxy k s)

Methods

succ :: Proxy k s -> Proxy k s

pred :: Proxy k s -> Proxy k s

toEnum :: Int -> Proxy k s

fromEnum :: Proxy k s -> Int

enumFrom :: Proxy k s -> [Proxy k s]

enumFromThen :: Proxy k s -> Proxy k s -> [Proxy k s]

enumFromTo :: Proxy k s -> Proxy k s -> [Proxy k s]

enumFromThenTo :: Proxy k s -> Proxy k s -> Proxy k s -> [Proxy k s]

Eq (Proxy k s)

Methods

(==) :: Proxy k s -> Proxy k s -> Bool

(/=) :: Proxy k s -> Proxy k s -> Bool

Ord (Proxy k s)

Methods

compare :: Proxy k s -> Proxy k s -> Ordering

(<) :: Proxy k s -> Proxy k s -> Bool

(<=) :: Proxy k s -> Proxy k s -> Bool

(>) :: Proxy k s -> Proxy k s -> Bool

(>=) :: Proxy k s -> Proxy k s -> Bool

max :: Proxy k s -> Proxy k s -> Proxy k s

min :: Proxy k s -> Proxy k s -> Proxy k s

Read (Proxy k s)

Methods

readsPrec :: Int -> ReadS (Proxy k s)

readList :: ReadS [Proxy k s]

readPrec :: ReadPrec (Proxy k s)

readListPrec :: ReadPrec [Proxy k s]

Show (Proxy k s)

Methods

showsPrec :: Int -> Proxy k s -> ShowS

show :: Proxy k s -> String

showList :: [Proxy k s] -> ShowS

Ix (Proxy k s)

Methods

range :: (Proxy k s, Proxy k s) -> [Proxy k s]

index :: (Proxy k s, Proxy k s) -> Proxy k s -> Int

unsafeIndex :: (Proxy k s, Proxy k s) -> Proxy k s -> Int

inRange :: (Proxy k s, Proxy k s) -> Proxy k s -> Bool

rangeSize :: (Proxy k s, Proxy k s) -> Int

unsafeRangeSize :: (Proxy k s, Proxy k s) -> Int

Generic (Proxy k t)

Associated Types

type Rep (Proxy k t) :: * -> *

Methods

from :: Proxy k t -> Rep (Proxy k t) x

to :: Rep (Proxy k t) x -> Proxy k t

Semigroup (Proxy k s)

Methods

(<>) :: Proxy k s -> Proxy k s -> Proxy k s

sconcat :: NonEmpty (Proxy k s) -> Proxy k s

stimes :: Integral b => b -> Proxy k s -> Proxy k s

Monoid (Proxy k s)

Methods

mempty :: Proxy k s

mappend :: Proxy k s -> Proxy k s -> Proxy k s

mconcat :: [Proxy k s] -> Proxy k s

FromJSON (Proxy k a)

Methods

parseJSON :: Value -> Parser (Proxy k a)

parseJSONList :: Value -> Parser [Proxy k a]

ToJSON (Proxy k a)

Methods

toJSON :: Proxy k a -> Value

toEncoding :: Proxy k a -> Encoding

toJSONList :: [Proxy k a] -> Value

toEncodingList :: [Proxy k a] -> Encoding

type Rep1 (Proxy *)

type Rep1 (Proxy *) = D1 (MetaData "Proxy" "Data.Proxy" "base" False) (C1 (MetaCons "Proxy" PrefixI False) U1)

type Rep (Proxy k t)

type Rep (Proxy k t) = D1 (MetaData "Proxy" "Data.Proxy" "base" False) (C1 (MetaCons "Proxy" PrefixI False) U1)