Data.Registry.Hedgehog.AesonGenerators

This module provides generators for JSON values

Since the Value data type is an ADT with different alternatives and a recursive data type we need to control how many of each variant (Number, String, Array, etc...) we generate and how deeply we recurse when generating arrays and objects which themselves contain Values.

A registry is used to store all the generators and the current generation configuration

In order to control the recursivity we tag the type of Values we generate:

• Tag Simple Value is for generating Null, Number, String, Boolean
• Tag Recurse Value is for generating Array and Object

And we put a Depth parameter in the registry. That parameter is decremented every time we generate values for an Array or an Object

Documentation

genValue :: Gen Value

Generator for a default JSON value

genValueWith :: (Registry _ _ -> Registry _ _) -> Gen Value

Generator for a JSON value with an adjusted set of generators

For example: - change the recursive depth of the generation: genValueWith (setDepth 5) - change the number of elements in an array or an object: genValueWith (setFieldsNb 5) - change the generator used to generate field names in an object: genValueWith (setFieldNames (elements ["a", "b", "c"])) - use a custom text generator: genValueWith (setGen myTextGenerator) - change the range used for generating numbers: genValueWith (setRange (linear @Int 0 20))

genNumberValue :: Gen Value

Specialized generator for a number value

genValueFor :: Registry _ _ -> Gen Value

Generate a JSON value with a given set of generators to be used when recursing

recursiveGens :: Registry _ _ -> Registry _ _

Set of generators for JSON values including recursive values like arrays and objects In order to control the recursivity of the Value data type we produce several types for JSON values using tags: Recurse Value is a generated value to be used when generating an array or an object Simple Value is a generated value that is either: a string, a number, a bool, a null value

simpleGens :: Registry _ _

Set of generators for non-recursive JSON values Those value are tagged as Simple but we can also extract a Gen Value from this list

Individual generators

genRecursiveValue :: Tag "Array" Value -> Tag "Object" Value -> Tag "Simple" Value -> Gen Value

Create a generator for a Value which can possibly be recursive if it is an array or an object

untagSimpleValue :: Tag "Simple" Value -> Value

Drop the tag on a Value

genSimpleValue :: Tag "Null" Value -> Tag "Bool" Value -> Tag "Number" Value -> Tag "String" Value -> Gen (Tag "Simple" Value)

Create a generator for a non-recursive Value (i.e. not an array or an object)

genNull :: Gen (Tag "Null" Value)

Generator for the Null value

genBool :: Gen (Tag "Bool" Value)

Generator for a boolean value

genText :: Range Int -> Gen Text

Generator for some Text

genString :: Text -> Tag "String" Value

Generator for a string value

genNumber :: Range Integer -> Gen (Tag "Number" Value)

Generator for a number value

genArray :: [Tag "Recurse" Value] -> Tag "Array" Value

Generator for an array value

genObject :: [FieldName] -> [Tag "Recurse" Value] -> Tag "Object" Value

Generator for an object value

Support functions

gen :: forall a b. (ApplyVariadic Gen a b, Typeable a, Typeable b) => a -> Typed b

Simplification for funTo @Gen when adding a new function to the registry

setGen :: Typeable a => Gen a -> Registry _ _ -> Registry _ _

set a specific generator on top of the list of generators

setRange :: Typeable a => Range a -> Registry _ _ -> Registry _ _

set a specific range on top of the list of generators

listOf :: forall a. Int -> Int -> Gen a -> Gen [a]

Generate a list of min' to max' elements

setDepth :: Depth -> Registry _ _ -> Registry _ _

Simplification for setting a new recursion depth on the registry

decrementDepth :: Registry _ _ -> Registry _ _

Decrement the depth of generation during recursion

setFieldsNb :: Int -> Registry _ _ -> Registry _ _

Set the number of fields in an object

setFieldNames :: Gen FieldName -> Registry _ _ -> Registry _ _

Set a generator for field names

newtype Depth

Depth of generated Values

Constructors

Depth

Fields

• unDepth :: Int

Instances

Num Depth

Defined in Data.Registry.Hedgehog.AesonGenerators

Methods

(+) :: Depth -> Depth -> Depth

(-) :: Depth -> Depth -> Depth

(*) :: Depth -> Depth -> Depth

negate :: Depth -> Depth

abs :: Depth -> Depth

signum :: Depth -> Depth

fromInteger :: Integer -> Depth

Show Depth

Defined in Data.Registry.Hedgehog.AesonGenerators

Methods

showsPrec :: Int -> Depth -> ShowS

show :: Depth -> String

showList :: [Depth] -> ShowS

Eq Depth

Defined in Data.Registry.Hedgehog.AesonGenerators

Methods

(==) :: Depth -> Depth -> Bool

(/=) :: Depth -> Depth -> Bool

newtype FieldName

Newtype for the name of fields in an object

Constructors

FieldName

Fields

• unFieldName :: Text

Instances

Read FieldName

Defined in Data.Registry.Hedgehog.AesonGenerators

Methods

readsPrec :: Int -> ReadS FieldName

readList :: ReadS [FieldName]

readPrec :: ReadPrec FieldName

readListPrec :: ReadPrec [FieldName]

Show FieldName

Defined in Data.Registry.Hedgehog.AesonGenerators

Methods

showsPrec :: Int -> FieldName -> ShowS

show :: FieldName -> String

showList :: [FieldName] -> ShowS

Eq FieldName

Defined in Data.Registry.Hedgehog.AesonGenerators

Methods

(==) :: FieldName -> FieldName -> Bool

(/=) :: FieldName -> FieldName -> Bool