Copyright	(c) 2019 Felix Paulusma
License	MIT
Maintainer	felix.paulusma@gmail.com
Stability	experimental
Safe Haskell	None
Language	Haskell2010

Data.SafeJSON.Test

Contents

Consistency checks
- Using TypeApplications
- Using a Proxy argument
Unit tests
- Migration tests
  - Synonyms
- Round trip tests
Property tests
Re-export for convenience

Description

This module contains some functions to use for testing SafeJSON and Migrate instances.

Synopsis

testConsistency :: forall a. SafeJSON a => Assertion
testConsistency' :: forall a. SafeJSON a => Proxy a -> Assertion
testMigration :: (Show a, Eq a, Migrate a) => MigrateFrom a -> a -> Assertion
testReverseMigration :: (Show a, Eq a, Migrate (Reverse a)) => MigrateFrom (Reverse a) -> a -> Assertion
(<=?) :: (Show a, Eq a, Migrate a) => MigrateFrom a -> a -> Assertion
(>=?) :: (Show a, Eq a, Migrate (Reverse a)) => MigrateFrom (Reverse a) -> a -> Assertion
testRoundTrip :: forall a. (Show a, Eq a, SafeJSON a) => a -> Assertion
migrateRoundTrip :: forall a. (Eq a, Show a, SafeJSON a, Migrate a) => MigrateFrom a -> Assertion
migrateReverseRoundTrip :: forall a. (Eq a, Show a, SafeJSON a, Migrate (Reverse a)) => MigrateFrom (Reverse a) -> Assertion
type TestMigrate a b = (Eq a, Show b, Arbitrary b, SafeJSON a, Migrate a, MigrateFrom a ~ b)
type TestReverseMigrate a b = (Eq a, Show b, Arbitrary b, SafeJSON a, Migrate (Reverse a), MigrateFrom (Reverse a) ~ b)
testRoundTripProp :: forall a. (Eq a, Show a, Arbitrary a, SafeJSON a) => String -> TestTree
migrateRoundTripProp :: forall a b. TestMigrate a b => String -> TestTree
migrateReverseRoundTripProp :: forall a b. TestReverseMigrate a b => String -> TestTree
testRoundTripProp' :: forall a. (Eq a, Show a, Arbitrary a, SafeJSON a) => Proxy a -> String -> TestTree
migrateRoundTripProp' :: forall a b. TestMigrate a b => Proxy (a, b) -> String -> TestTree
migrateReverseRoundTripProp' :: forall a b. TestReverseMigrate a b => Proxy (a, b) -> String -> TestTree
data Proxy (t :: k) = Proxy

Consistency checks

It is advised to always run testConsistency (or testConsistency') for all your types that have a SafeJSON instance.

Note that any type that fails this test will also fail any safeFromJSON parsing!

Using TypeApplications

testConsistency :: forall a. SafeJSON a => Assertion Source #

Useful in test suites. Will fail if anything in the chain of your types is inconsistent.

Example usage:

Expand

testConsistency @MyType

Using a Proxy argument

testConsistency' :: forall a. SafeJSON a => Proxy a -> Assertion Source #

Useful in test suites. Will fail if anything in the chain of your types is inconsistent.

Unit tests

Migration tests

These tests can be used to verify the implemented migrate function acts as expected.

testMigration :: (Show a, Eq a, Migrate a) => MigrateFrom a -> a -> Assertion Source #

Migration test. Mostly useful as regression test.

First argument is the older type which should turn into the second argument after migrating using migrate.

Just (migrate a) == parseMaybe safeFromJSON (safeToJSON a)

testReverseMigration :: (Show a, Eq a, Migrate (Reverse a)) => MigrateFrom (Reverse a) -> a -> Assertion Source #

Similar to testMigration, but using Migrate (Reverse a).

The first argument here is the newer type, which will be migrated back to the expected second argument (older type).

Just (unReverse $ migrate a) == parseMaybe safeFromJSON (safeToJSON a)

Synonyms

(<=?) :: (Show a, Eq a, Migrate a) => MigrateFrom a -> a -> Assertion infix 1 Source #

Operator synonymous with testMigration

(>=?) :: (Show a, Eq a, Migrate (Reverse a)) => MigrateFrom (Reverse a) -> a -> Assertion infix 1 Source #

Operator synonymous with testReverseMigration

These tests can be used to verify that round trips are consistent. Either directly (testRoundTrip), through a forward migration (migrateRoundTrip) or a reversed backward migration (migrateReverseRoundTrip).

testRoundTrip :: forall a. (Show a, Eq a, SafeJSON a) => a -> Assertion Source #

Tests that the following holds:

Just a == parseMaybe safeFromJSON (safeToJSON a)

migrateRoundTrip :: forall a. (Eq a, Show a, SafeJSON a, Migrate a) => MigrateFrom a -> Assertion Source #

This test verifies that direct migration, and migration through encoding and decoding to the newer type, is equivalent.

migrateReverseRoundTrip :: forall a. (Eq a, Show a, SafeJSON a, Migrate (Reverse a)) => MigrateFrom (Reverse a) -> Assertion Source #

Similar to migrateRoundTrip, but tests the migration from a newer type to the older type, in case of a Migrate (Reverse a) instance

Property tests

Useful if your types also have Arbitrary instances.

Constraint synonyms for readability

type TestMigrate a b = (Eq a, Show b, Arbitrary b, SafeJSON a, Migrate a, MigrateFrom a ~ b) Source #

Constraints for migrating from a previous version

type TestReverseMigrate a b = (Eq a, Show b, Arbitrary b, SafeJSON a, Migrate (Reverse a), MigrateFrom (Reverse a) ~ b) Source #

Constraints for migrating from a future version

Using TypeApplications

testRoundTripProp :: forall a. (Eq a, Show a, Arbitrary a, SafeJSON a) => String -> TestTree Source #

Tests that the following holds for all a:

Just a == parseMaybe safeFromJSON (safeToJSON a)

Example usage:

Expand

testRoundTripProp @MyType s

migrateRoundTripProp :: forall a b. TestMigrate a b => String -> TestTree Source #

This test verifies that direct migration, and migration through encoding and decoding to the newer type, is equivalent for all a.

Just (migrate a) == parseMaybe safeFromJSON (safeToJSON a)

Example usage:

Expand

migrateRoundTripProp @NewType @OldType s

migrateReverseRoundTripProp :: forall a b. TestReverseMigrate a b => String -> TestTree Source #

Similar to migrateRoundTripProp, but tests the migration from a newer type to the older type, in case of a Migrate (Reverse a) instance.

Just (unReverse $ migrate a) == parseMaybe safeFromJSON (safeToJSON a)

Example usage:

Expand

Please also note the reversing of the type applications.

migrateReverseRoundTripProp @OldType @NewType s

Using a Proxy argument

testRoundTripProp' :: forall a. (Eq a, Show a, Arbitrary a, SafeJSON a) => Proxy a -> String -> TestTree Source #

Tests that the following holds for all a:

Just a == parseMaybe safeFromJSON (safeToJSON a)

migrateRoundTripProp' :: forall a b. TestMigrate a b => Proxy (a, b) -> String -> TestTree Source #

This test verifies that direct migration, and migration through encoding and decoding to the newer type, is equivalent for all a.

Just (migrate a) == parseMaybe safeFromJSON (safeToJSON a)

migrateReverseRoundTripProp' :: forall a b. TestReverseMigrate a b => Proxy (a, b) -> String -> TestTree Source #

Similar to migrateRoundTripProp, but tests the migration from a newer type to the older type, in case of a Migrate (Reverse a) instance.

Just (unReverse $ migrate a) == parseMaybe safeFromJSON (safeToJSON a)

Re-export for convenience

data Proxy (t :: k) #

Proxy is a type that holds no data, but has a phantom parameter of arbitrary type (or even kind). Its use is to provide type information, even though there is no value available of that type (or it may be too costly to create one).

Historically, Proxy :: Proxy a is a safer alternative to the undefined :: a idiom.

>>> Proxy :: Proxy (Void, Int -> Int)
Proxy

Proxy can even hold types of higher kinds,

>>> Proxy :: Proxy Either
Proxy

>>> Proxy :: Proxy Functor
Proxy

>>> Proxy :: Proxy complicatedStructure
Proxy

Constructors

Proxy

Instances

Instances details

Generic1 (Proxy :: k -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Proxy :: k -> Type # Methods from1 :: forall (a :: k0). Proxy a -> Rep1 Proxy a # to1 :: forall (a :: k0). Rep1 Proxy a -> Proxy a #
Monad (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods (>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b # (>>) :: Proxy a -> Proxy b -> Proxy b # return :: a -> Proxy a #
Functor (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods fmap :: (a -> b) -> Proxy a -> Proxy b # (<$) :: a -> Proxy b -> Proxy a #
Applicative (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods pure :: a -> Proxy a # (<>) :: Proxy (a -> b) -> Proxy a -> Proxy b # liftA2 :: (a -> b -> c) -> Proxy a -> Proxy b -> Proxy c # (>) :: Proxy a -> Proxy b -> Proxy b # (<*) :: Proxy a -> Proxy b -> Proxy a #
Foldable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> 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 #
Traversable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b) # sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a) # mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b) # sequence :: Monad m => Proxy (m a) -> m (Proxy a) #
ToJSON1 (Proxy :: Type -> Type)
Instance details Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Proxy a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Proxy a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Proxy a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Proxy a] -> Encoding #
FromJSON1 (Proxy :: Type -> Type)
Instance details Defined in Data.Aeson.Types.FromJSON Methods liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Proxy a) # liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Proxy a] #
Alternative (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods empty :: Proxy a # (<\|>) :: Proxy a -> Proxy a -> Proxy a # some :: Proxy a -> Proxy [a] # many :: Proxy a -> Proxy [a] #
MonadPlus (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods mzero :: Proxy a # mplus :: Proxy a -> Proxy a -> Proxy a #
Hashable1 (Proxy :: Type -> Type)
Instance details Defined in Data.Hashable.Class Methods liftHashWithSalt :: (Int -> a -> Int) -> Int -> Proxy a -> Int #
Bounded (Proxy t)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods minBound :: Proxy t # maxBound :: Proxy t #
Enum (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods succ :: Proxy s -> Proxy s # pred :: Proxy s -> Proxy s # toEnum :: Int -> Proxy s # fromEnum :: Proxy s -> Int # enumFrom :: Proxy s -> [Proxy s] # enumFromThen :: Proxy s -> Proxy s -> [Proxy s] # enumFromTo :: Proxy s -> Proxy s -> [Proxy s] # enumFromThenTo :: Proxy s -> Proxy s -> Proxy s -> [Proxy s] #
Eq (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods (==) :: Proxy s -> Proxy s -> Bool # (/=) :: Proxy s -> Proxy s -> Bool #
Ord (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods compare :: Proxy s -> Proxy s -> Ordering # (<) :: Proxy s -> Proxy s -> Bool # (<=) :: Proxy s -> Proxy s -> Bool # (>) :: Proxy s -> Proxy s -> Bool # (>=) :: Proxy s -> Proxy s -> Bool # max :: Proxy s -> Proxy s -> Proxy s # min :: Proxy s -> Proxy s -> Proxy s #
Read (Proxy t)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods readsPrec :: Int -> ReadS (Proxy t) # readList :: ReadS [Proxy t] # readPrec :: ReadPrec (Proxy t) # readListPrec :: ReadPrec [Proxy t] #
Show (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods showsPrec :: Int -> Proxy s -> ShowS # show :: Proxy s -> String # showList :: [Proxy s] -> ShowS #
Ix (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods range :: (Proxy s, Proxy s) -> [Proxy s] # index :: (Proxy s, Proxy s) -> Proxy s -> Int # unsafeIndex :: (Proxy s, Proxy s) -> Proxy s -> Int # inRange :: (Proxy s, Proxy s) -> Proxy s -> Bool # rangeSize :: (Proxy s, Proxy s) -> Int # unsafeRangeSize :: (Proxy s, Proxy s) -> Int #
Generic (Proxy t)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Proxy t) :: Type -> Type # Methods from :: Proxy t -> Rep (Proxy t) x # to :: Rep (Proxy t) x -> Proxy t #
Semigroup (Proxy s)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods (<>) :: Proxy s -> Proxy s -> Proxy s # sconcat :: NonEmpty (Proxy s) -> Proxy s # stimes :: Integral b => b -> Proxy s -> Proxy s #
Monoid (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods mempty :: Proxy s # mappend :: Proxy s -> Proxy s -> Proxy s # mconcat :: [Proxy s] -> Proxy s #
Hashable (Proxy a)
Instance details Defined in Data.Hashable.Class Methods hashWithSalt :: Int -> Proxy a -> Int # hash :: Proxy a -> Int #
ToJSON (Proxy a)
Instance details Defined in Data.Aeson.Types.ToJSON Methods toJSON :: Proxy a -> Value # toEncoding :: Proxy a -> Encoding # toJSONList :: [Proxy a] -> Value # toEncodingList :: [Proxy a] -> Encoding #
FromJSON (Proxy a)
Instance details Defined in Data.Aeson.Types.FromJSON Methods parseJSON :: Value -> Parser (Proxy a) # parseJSONList :: Value -> Parser [Proxy a] #
SafeJSON (Proxy a) Source #
Instance details Defined in Data.SafeJSON.Internal Methods version :: Version (Proxy a) Source # kind :: Kind (Proxy a) Source # safeTo :: Proxy a -> Contained Value Source # safeFrom :: Value -> Contained (Parser (Proxy a)) Source # typeName :: Proxy (Proxy a) -> String Source # internalConsistency :: Consistency (Proxy a) objectProfile :: Profile (Proxy a) Source #
type Rep1 (Proxy :: k -> Type)
Instance details Defined in GHC.Generics type Rep1 (Proxy :: k -> Type) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: k -> Type))
type Rep (Proxy t)
Instance details Defined in GHC.Generics type Rep (Proxy t) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: Type -> Type))

Consistency checks

Using TypeApplications

Example usage:

Using a Proxy argument

Unit tests

Migration tests

Synonyms

Round trip tests

Property tests

Constraint synonyms for readability

Using TypeApplications

Example usage:

Example usage:

Example usage:

Using a Proxy argument

Re-export for convenience

Instances