GraphQL.Internal.Validation

Transform GraphQL query documents from AST into valid structures

This corresponds roughly to the Validation section of the specification, except where noted.

One core difference is that this module doesn't attempt to do any type-level validation, as we attempt to defer all of that to the Haskell type checker.

Deliberately not going to do:

• field selections on compound types https://facebook.github.io/graphql/#sec-Field-Selections-on-Objects-Interfaces-and-Unions-Types
• leaf field selections https://facebook.github.io/graphql/#sec-Leaf-Field-Selections
• argument names https://facebook.github.io/graphql/#sec-Argument-Names
• argument value type correctness https://facebook.github.io/graphql/#sec-Argument-Values-Type-Correctness
• fragment spread type existence https://facebook.github.io/graphql/#sec-Fragment-Spread-Type-Existence
• fragments on compound types https://facebook.github.io/graphql/#sec-Fragments-On-Composite-Types
• fragment spread is possible https://facebook.github.io/graphql/#sec-Fragment-spread-is-possible
• directives are defined https://facebook.github.io/graphql/#sec-Directives-Are-Defined
• directives are in valid locations https://facebook.github.io/graphql/#sec-Directives-Are-In-Valid-Locations
• variable default values are correctly typed https://facebook.github.io/graphql/#sec-Variable-Default-Values-Are-Correctly-Typed
• variables are input types https://facebook.github.io/graphql/#sec-Variables-Are-Input-Types
• all variable usages are allowed https://facebook.github.io/graphql/#sec-All-Variable-Usages-are-Allowed

Because all of the above rely on type checking.

Documentation

data ValidationError

Errors arising from validating a document.

Constructors

DuplicateOperation Name

DuplicateOperation means there was more than one operation defined with the given name.

https://facebook.github.io/graphql/#sec-Operation-Name-Uniqueness

MixedAnonymousOperations Int [Name]

MixedAnonymousOperations means there was more than one operation defined in a document with an anonymous operation.

https://facebook.github.io/graphql/#sec-Lone-Anonymous-Operation

DuplicateArgument Name

DuplicateArgument means that multiple copies of the same argument was given to the same field, directive, etc.

DuplicateFragmentDefinition Name

DuplicateFragmentDefinition means that there were more than one fragment defined with the same name.

NoSuchFragment Name

NoSuchFragment means there was a reference to a fragment in a fragment spread but we couldn't find any fragment with that name.

DuplicateDirective Name

DuplicateDirective means there were two copies of the same directive given in the same place.

https://facebook.github.io/graphql/#sec-Directives-Are-Unique-Per-Location

DuplicateVariableDefinition Variable

There were multiple variables defined with the same name.

CircularFragmentSpread Name

CircularFragmentSpread means that a fragment definition contains a fragment spread that itself is a fragment definition that contains a fragment spread referring to the first fragment spread.

UnusedFragments (Set Name)

UnusedFragments means that fragments were defined that weren't used. https://facebook.github.io/graphql/#sec-Fragments-Must-Be-Used

UnusedVariables (Set Variable)

Variables were defined without being used. https://facebook.github.io/graphql/#sec-All-Variables-Used

UndefinedVariable Variable

A variable was used without being defined. https://facebook.github.io/graphql/#sec-All-Variable-Uses-Defined

InvalidValue Value

Value in AST wasn't valid.

InvalidDefaultValue Value

Default value in AST contained variables.

MismatchedNames Name Name

Two different names given for the same response key.

MismatchedArguments Name

Two different sets of arguments given for the same response key.

IncompatibleFields Name

Two fields had the same response key, one was a leaf, the other was not.

TypeConditionNotFound Name

There's a type condition that's not present in the schema.

Instances

Eq ValidationError

Methods

(==) :: ValidationError -> ValidationError -> Bool

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

Show ValidationError

Methods

showsPrec :: Int -> ValidationError -> ShowS

show :: ValidationError -> String

showList :: [ValidationError] -> ShowS

GraphQLError ValidationError

Methods

formatError :: ValidationError -> Text

toError :: ValidationError -> Error

type ValidationErrors = NonEmpty ValidationError

data QueryDocument value

A valid query document.

Construct this using validate on an QueryDocument.

Constructors

LoneAnonymousOperation (Operation value)

The query document contains a single anonymous operation.

MultipleOperations (Operations value)

The query document contains multiple uniquely-named operations.

Instances

Eq value => Eq (QueryDocument value)

Methods

(==) :: QueryDocument value -> QueryDocument value -> Bool

(/=) :: QueryDocument value -> QueryDocument value -> Bool

Show value => Show (QueryDocument value)

Methods

showsPrec :: Int -> QueryDocument value -> ShowS

show :: QueryDocument value -> String

showList :: [QueryDocument value] -> ShowS

validate :: Schema -> QueryDocument -> Either (NonEmpty ValidationError) (QueryDocument VariableValue)

Turn a parsed document into a known valid one.

The document is known to be syntactically valid, as we've got its AST. Here, we confirm that it's semantically valid (modulo types).

getErrors :: Schema -> QueryDocument -> [ValidationError]

Identify all of the validation errors in doc.

An empty list means no errors.

https://facebook.github.io/graphql/#sec-Validation

Operating on validated documents

data Operation value

Instances

Functor Operation

Methods

fmap :: (a -> b) -> Operation a -> Operation b

(<$) :: a -> Operation b -> Operation a

Foldable Operation

Methods

fold :: Monoid m => Operation m -> m

foldMap :: Monoid m => (a -> m) -> Operation a -> m

foldr :: (a -> b -> b) -> b -> Operation a -> b

foldr' :: (a -> b -> b) -> b -> Operation a -> b

foldl :: (b -> a -> b) -> b -> Operation a -> b

foldl' :: (b -> a -> b) -> b -> Operation a -> b

foldr1 :: (a -> a -> a) -> Operation a -> a

foldl1 :: (a -> a -> a) -> Operation a -> a

toList :: Operation a -> [a]

null :: Operation a -> Bool

length :: Operation a -> Int

elem :: Eq a => a -> Operation a -> Bool

maximum :: Ord a => Operation a -> a

minimum :: Ord a => Operation a -> a

sum :: Num a => Operation a -> a

product :: Num a => Operation a -> a

Traversable Operation

Methods

traverse :: Applicative f => (a -> f b) -> Operation a -> f (Operation b)

sequenceA :: Applicative f => Operation (f a) -> f (Operation a)

mapM :: Monad m => (a -> m b) -> Operation a -> m (Operation b)

sequence :: Monad m => Operation (m a) -> m (Operation a)

Eq value => Eq (Operation value)

Methods

(==) :: Operation value -> Operation value -> Bool

(/=) :: Operation value -> Operation value -> Bool

Show value => Show (Operation value)

Methods

showsPrec :: Int -> Operation value -> ShowS

show :: Operation value -> String

showList :: [Operation value] -> ShowS

getSelectionSet :: Operation value -> SelectionSetByType value

Get the selection set for an operation.

Executing validated documents

data VariableDefinition

Defines a variable within the context of an operation.

See https://facebook.github.io/graphql/#sec-Language.Variables

Constructors

VariableDefinition

Fields

• variable :: Variable

  The name of the variable

• variableType :: Type

  The type of the variable

• defaultValue :: Maybe Value

  An optional default value for the variable

Instances

Eq VariableDefinition

Methods

(==) :: VariableDefinition -> VariableDefinition -> Bool

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

Ord VariableDefinition

Methods

compare :: VariableDefinition -> VariableDefinition -> Ordering

(<) :: VariableDefinition -> VariableDefinition -> Bool

(<=) :: VariableDefinition -> VariableDefinition -> Bool

(>) :: VariableDefinition -> VariableDefinition -> Bool

(>=) :: VariableDefinition -> VariableDefinition -> Bool

max :: VariableDefinition -> VariableDefinition -> VariableDefinition

min :: VariableDefinition -> VariableDefinition -> VariableDefinition

Show VariableDefinition

Methods

showsPrec :: Int -> VariableDefinition -> ShowS

show :: VariableDefinition -> String

showList :: [VariableDefinition] -> ShowS

type VariableValue = Value' (Either VariableDefinition ConstScalar)

A GraphQL value which might contain some defined variables.

data Variable

Instances

Eq Variable

Methods

(==) :: Variable -> Variable -> Bool

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

Ord Variable

Methods

compare :: Variable -> Variable -> Ordering

(<) :: Variable -> Variable -> Bool

(<=) :: Variable -> Variable -> Bool

(>) :: Variable -> Variable -> Bool

(>=) :: Variable -> Variable -> Bool

max :: Variable -> Variable -> Variable

min :: Variable -> Variable -> Variable

Show Variable

Methods

showsPrec :: Int -> Variable -> ShowS

show :: Variable -> String

showList :: [Variable] -> ShowS

Arbitrary Variable

Methods

arbitrary :: Gen Variable

shrink :: Variable -> [Variable]

data Type

Constructors

TypeNamed NamedType

TypeList ListType

TypeNonNull NonNullType

Instances

Eq Type

Methods

(==) :: Type -> Type -> Bool

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

Ord Type

Methods

compare :: Type -> Type -> Ordering

(<) :: Type -> Type -> Bool

(<=) :: Type -> Type -> Bool

(>) :: Type -> Type -> Bool

(>=) :: Type -> Type -> Bool

max :: Type -> Type -> Type

min :: Type -> Type -> Type

Show Type

Methods

showsPrec :: Int -> Type -> ShowS

show :: Type -> String

showList :: [Type] -> ShowS

Resolving queries

data SelectionSetByType value

Instances

Functor SelectionSetByType

Methods

fmap :: (a -> b) -> SelectionSetByType a -> SelectionSetByType b

(<$) :: a -> SelectionSetByType b -> SelectionSetByType a

Foldable SelectionSetByType

Methods

fold :: Monoid m => SelectionSetByType m -> m

foldMap :: Monoid m => (a -> m) -> SelectionSetByType a -> m

foldr :: (a -> b -> b) -> b -> SelectionSetByType a -> b

foldr' :: (a -> b -> b) -> b -> SelectionSetByType a -> b

foldl :: (b -> a -> b) -> b -> SelectionSetByType a -> b

foldl' :: (b -> a -> b) -> b -> SelectionSetByType a -> b

foldr1 :: (a -> a -> a) -> SelectionSetByType a -> a

foldl1 :: (a -> a -> a) -> SelectionSetByType a -> a

toList :: SelectionSetByType a -> [a]

null :: SelectionSetByType a -> Bool

length :: SelectionSetByType a -> Int

elem :: Eq a => a -> SelectionSetByType a -> Bool

maximum :: Ord a => SelectionSetByType a -> a

minimum :: Ord a => SelectionSetByType a -> a

sum :: Num a => SelectionSetByType a -> a

product :: Num a => SelectionSetByType a -> a

Traversable SelectionSetByType

Methods

traverse :: Applicative f => (a -> f b) -> SelectionSetByType a -> f (SelectionSetByType b)

sequenceA :: Applicative f => SelectionSetByType (f a) -> f (SelectionSetByType a)

mapM :: Monad m => (a -> m b) -> SelectionSetByType a -> m (SelectionSetByType b)

sequence :: Monad m => SelectionSetByType (m a) -> m (SelectionSetByType a)

Eq value => Eq (SelectionSetByType value)

Methods

(==) :: SelectionSetByType value -> SelectionSetByType value -> Bool

(/=) :: SelectionSetByType value -> SelectionSetByType value -> Bool

Ord value => Ord (SelectionSetByType value)

Methods

compare :: SelectionSetByType value -> SelectionSetByType value -> Ordering

(<) :: SelectionSetByType value -> SelectionSetByType value -> Bool

(<=) :: SelectionSetByType value -> SelectionSetByType value -> Bool

(>) :: SelectionSetByType value -> SelectionSetByType value -> Bool

(>=) :: SelectionSetByType value -> SelectionSetByType value -> Bool

max :: SelectionSetByType value -> SelectionSetByType value -> SelectionSetByType value

min :: SelectionSetByType value -> SelectionSetByType value -> SelectionSetByType value

Show value => Show (SelectionSetByType value)

Methods

showsPrec :: Int -> SelectionSetByType value -> ShowS

show :: SelectionSetByType value -> String

showList :: [SelectionSetByType value] -> ShowS

newtype SelectionSet value

A selection set, almost fully validated.

Sub-selection sets might not be validated.

Constructors

SelectionSet (OrderedMap ResponseKey (Field value))

Instances

Eq value => Eq (SelectionSet value)

Methods

(==) :: SelectionSet value -> SelectionSet value -> Bool

(/=) :: SelectionSet value -> SelectionSet value -> Bool

Ord value => Ord (SelectionSet value)

Methods

compare :: SelectionSet value -> SelectionSet value -> Ordering

(<) :: SelectionSet value -> SelectionSet value -> Bool

(<=) :: SelectionSet value -> SelectionSet value -> Bool

(>) :: SelectionSet value -> SelectionSet value -> Bool

(>=) :: SelectionSet value -> SelectionSet value -> Bool

max :: SelectionSet value -> SelectionSet value -> SelectionSet value

min :: SelectionSet value -> SelectionSet value -> SelectionSet value

Show value => Show (SelectionSet value)

Methods

showsPrec :: Int -> SelectionSet value -> ShowS

show :: SelectionSet value -> String

showList :: [SelectionSet value] -> ShowS

getSelectionSetForType

Arguments

:: Eq value

=> ObjectTypeDefinition

The type of the object that the selection set is for

-> SelectionSetByType value

A selection set with type conditions, obtained from the validation process

-> Either ValidationErrors (SelectionSet value)

A flattened selection set without type conditions. It's possible that some of the fields in various types are not mergeable, in which case, we'll return a validation error.

Once we know the GraphQL type of the object that a selection set (i.e. a SelectionSetByType) is for, we can eliminate all the irrelevant types and present a single, flattened map of ResponseKey to Field.

data Field value

A field ready to be resolved.

Instances

Functor Field

Methods

fmap :: (a -> b) -> Field a -> Field b

(<$) :: a -> Field b -> Field a

Foldable Field

Methods

fold :: Monoid m => Field m -> m

foldMap :: Monoid m => (a -> m) -> Field a -> m

foldr :: (a -> b -> b) -> b -> Field a -> b

foldr' :: (a -> b -> b) -> b -> Field a -> b

foldl :: (b -> a -> b) -> b -> Field a -> b

foldl' :: (b -> a -> b) -> b -> Field a -> b

foldr1 :: (a -> a -> a) -> Field a -> a

foldl1 :: (a -> a -> a) -> Field a -> a

toList :: Field a -> [a]

null :: Field a -> Bool

length :: Field a -> Int

elem :: Eq a => a -> Field a -> Bool

maximum :: Ord a => Field a -> a

minimum :: Ord a => Field a -> a

sum :: Num a => Field a -> a

product :: Num a => Field a -> a

Traversable Field

Methods

traverse :: Applicative f => (a -> f b) -> Field a -> f (Field b)

sequenceA :: Applicative f => Field (f a) -> f (Field a)

mapM :: Monad m => (a -> m b) -> Field a -> m (Field b)

sequence :: Monad m => Field (m a) -> m (Field a)

Eq value => Eq (Field value)

Methods

(==) :: Field value -> Field value -> Bool

(/=) :: Field value -> Field value -> Bool

Ord value => Ord (Field value)

Methods

compare :: Field value -> Field value -> Ordering

(<) :: Field value -> Field value -> Bool

(<=) :: Field value -> Field value -> Bool

(>) :: Field value -> Field value -> Bool

(>=) :: Field value -> Field value -> Bool

max :: Field value -> Field value -> Field value

min :: Field value -> Field value -> Field value

Show value => Show (Field value)

Methods

showsPrec :: Int -> Field value -> ShowS

show :: Field value -> String

showList :: [Field value] -> ShowS

HasName (Field value)

Methods

getName :: Field value -> Name

lookupArgument :: Field value -> Name -> Maybe value

Get the value of an argument in a field.

getSubSelectionSet :: Field value -> Maybe (SelectionSetByType value)

Get the selection set within a field.

type ResponseKey = Name

A ResponseKey is the key under which a field appears in a response. If there's an alias, it's the alias, if not, it's the field name.

getResponseKey :: Field' spread value -> ResponseKey

Get the response key of a field.

"A field’s response key is its alias if an alias is provided, and it is otherwise the field’s name."

https://facebook.github.io/graphql/#sec-Field-Alias

Exported for testing

findDuplicates :: Ord a => [a] -> [a]

Return a list of all the elements with duplicates. The list of duplicates itself will not contain duplicates.

\xs -> findDuplicates @Int xs == ordNub (findDuplicates @Int xs)