Prospero.Validation

validate :: Array ValidationRule -> Array Selection -> GqlType -> Array GraphQLError

Run all validation rules, returning GraphQL errors

validateDepth :: Int -> ValidationRule

Validate that query depth does not exceed a maximum

validateFieldCount :: Int -> ValidationRule

Validate total number of fields does not exceed a maximum

validateComplexity :: Int -> ValidationRule

Validate query complexity with a simple cost model (each field = 1, each list multiplier = 10)

data ValidationError

Constructors

• FieldNotFound String String
• InvalidArgument String String
• DepthExceeded Int Int
• FieldCountExceeded Int Int
• ComplexityExceeded Int Int

Instances

• Eq ValidationError
• Show ValidationError

type ValidationRule = Array Selection -> GqlType -> Array ValidationError

type SelectionMetrics = { cost :: Int, depth :: Int, fieldCount :: Int }

Metrics computed in a single pass over the selection tree

analyzeSelections :: GqlType -> Array Selection -> SelectionMetrics

Compute depth, field count, and cost in a single traversal

measureDepth :: Array Selection -> Int

countFields :: Array Selection -> Int

lookupField :: String -> GqlType -> Maybe GqlField

isList :: GqlType -> Boolean