Input object null vs undefined

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macos-10.15, macos-latest, ubuntu-16.04, ubuntu-18.04, ubuntu-20.04]
+        os: [macos-10.15, macos-latest, ubuntu-18.04, ubuntu-20.04]
     steps:
     - uses: actions/checkout@v2
     - name: Set code coverage path 

Sources/GraphQL/Execution/Values.swift

@@ -35,16 +35,20 @@ func getArgumentValues(argDefs: [GraphQLArgumentDefinition], argASTs: [Argument]
     return try argDefs.reduce([:]) { result, argDef in
         var result = result
         let name = argDef.name
-        let valueAST = argASTMap[name]?.value
+        let argAST = argASTMap[name]
+
+        if let argAST = argAST {
+            let valueAST = argAST.value
 
-        let value = try valueFromAST(
-            valueAST: valueAST,
-            type: argDef.type,
-            variables: variableValues
-        ) ?? argDef.defaultValue
+            let value = try valueFromAST(
+                valueAST: valueAST,
+                type: argDef.type,
+                variables: variableValues
+            )
 
-        if let value = value {
             result[name] = value
+        } else {
+            result[name] = .null
         }
 
         return result
@@ -75,7 +79,7 @@ func getVariableValue(schema: GraphQLSchema, definitionAST: VariableDefinition,
     if errors.isEmpty {
         if input == .null {
             if let defaultValue = definitionAST.defaultValue {
-                return try valueFromAST(valueAST: defaultValue, type: inputType)!
+                return try valueFromAST(valueAST: defaultValue, type: inputType)
             }
             else if !(inputType is GraphQLNonNull) {
                 return .null
@@ -148,7 +152,7 @@ func coerceValue(type: GraphQLInputType, value: Map) throws -> Map? {
             var fieldValue = try coerceValue(type: field!.type, value: value[fieldName] ?? .null)
 
             if fieldValue == .null {
-                fieldValue = field.flatMap({ $0.defaultValue.map({ .string($0) }) })
+                fieldValue = field.flatMap({ $0.defaultValue })
             } else {
                 objCopy[fieldName] = fieldValue
             }

Sources/GraphQL/Map/Map.swift

@@ -11,6 +11,7 @@ public enum MapError : Error {
 // MARK: Map
 
 public enum Map {
+    case undefined
     case null
     case bool(Bool)
     case number(Number)
@@ -165,6 +166,13 @@ extension Map {
 // MARK: is<Type>
 
 extension Map {
+    public var isUndefined: Bool {
+        if case .undefined = self {
+            return true
+        }
+        return false
+    }
+
     public var isNull: Bool {
         if case .null = self {
             return true
@@ -206,6 +214,8 @@ extension Map {
 extension Map {
     public var typeDescription: String {
         switch self {
+        case .undefined:
+            return "undefined"
         case .null:
             return "null"
         case .bool:
@@ -259,6 +269,9 @@ extension Map {
         }
 
         switch self {
+        case .undefined:
+            return false
+
         case .null:
             return false
 
@@ -337,6 +350,9 @@ extension Map {
         }
 
         switch self {
+        case .undefined:
+            return "undefined"
+
         case .null:
             return "null"
 
@@ -645,6 +661,8 @@ extension Map : Codable {
         var container = encoder.singleValueContainer()
 
         switch self {
+        case .undefined:
+            fatalError("undefined values should have been excluded from encoding")
         case .null:
             try container.encodeNil()
         case let .bool(value):
@@ -660,8 +678,10 @@ extension Map : Codable {
             // Instead decode as a keyed container (like normal Dictionary) in the order of our OrderedDictionary
             var container = encoder.container(keyedBy: _DictionaryCodingKey.self)
             for (key, value) in dictionary {
-              let codingKey = _DictionaryCodingKey(stringValue: key)!
-              try container.encode(value, forKey: codingKey)
+                if !value.isUndefined {
+                    let codingKey = _DictionaryCodingKey(stringValue: key)!
+                    try container.encode(value, forKey: codingKey)
+                }
             }
         }
     }
@@ -711,6 +731,8 @@ public func == (lhs: Map, rhs: Map) -> Bool {
 extension Map : Hashable {
     public func hash(into hasher: inout Hasher) {
         switch self {
+        case .undefined:
+            hasher.combine(0)
         case .null:
             hasher.combine(0)
         case let .bool(value):
@@ -837,6 +859,8 @@ extension Map {
 
         func serialize(map: Map) -> String {
             switch map {
+            case .undefined:
+                return "undefined"
             case .null:
                 return "null"
             case let .bool(value):
@@ -891,8 +915,12 @@ extension Map {
             if debug {
                 indentLevel += 1
             }
+
+            let filtered = dictionary.filter({ item in
+                !item.value.isUndefined
+            })
 
-            for (key, value) in dictionary.sorted(by: {$0.0 < $1.0}) {
+            for (key, value) in filtered.sorted(by: {$0.0 < $1.0}) {
                 if debug {
                     string += "\n"
                     string += indent()
@@ -901,7 +929,7 @@ extension Map {
                     string += escape(key) + ":" + serialize(map: value)
                 }
 
-                if index != dictionary.count - 1 {
+                if index != filtered.count - 1 {
                     if debug {
                         string += ", "
                     } else {

Sources/GraphQL/Map/MapSerialization.swift

@@ -34,6 +34,8 @@ public struct MapSerialization {
 
     static func object(with map: Map) throws -> NSObject {
         switch map {
+        case .undefined:
+            fatalError("undefined values should have been excluded from serialization")
         case .null:
             return NSNull()
         case let .bool(value):
@@ -48,7 +50,9 @@ public struct MapSerialization {
             // Coerce to an unordered dictionary
             var unorderedDictionary: [String: NSObject] = [:]
             for (key, value) in dictionary {
-                try unorderedDictionary[key] = object(with: value)
+                if !value.isUndefined {
+                    try unorderedDictionary[key] = object(with: value)
+                }
             }
             return unorderedDictionary as NSDictionary
         }

Sources/GraphQL/Type/Definition.swift

@@ -1274,12 +1274,12 @@ func defineInputObjectFieldMap(
 
 public struct InputObjectField {
     public let type: GraphQLInputType
-    public let defaultValue: String?
+    public let defaultValue: Map?
     public let description: String?
 
     public init(type: GraphQLInputType, defaultValue: Map? = nil, description: String? = nil) {
         self.type = type
-        self.defaultValue = defaultValue?.description
+        self.defaultValue = defaultValue
         self.description = description
     }
 }
@@ -1290,13 +1290,13 @@ public final class InputObjectFieldDefinition {
     public let name: String
     public internal(set) var type: GraphQLInputType
     public let description: String?
-    public let defaultValue: String?
+    public let defaultValue: Map?
 
     init(
         name: String,
         type: GraphQLInputType,
         description: String? = nil,
-        defaultValue: String? = nil
+        defaultValue: Map? = nil
     ) {
         self.name = name
         self.type = type

Sources/GraphQL/Utilities/ValueFromAST.swift

@@ -17,18 +17,14 @@ import OrderedCollections
  * | Enum Value           | .string       |
  *
  */
-func valueFromAST(valueAST: Value?, type: GraphQLInputType, variables: [String: Map] = [:]) throws -> Map? {
+func valueFromAST(valueAST: Value, type: GraphQLInputType, variables: [String: Map] = [:]) throws -> Map {
     if let nonNullType = type as? GraphQLNonNull {
         // Note: we're not checking that the result of valueFromAST is non-null.
         // We're assuming that this query has been validated and the value used
         // here is of the correct type.
         return try valueFromAST(valueAST: valueAST, type: nonNullType.ofType as! GraphQLInputType, variables: variables)
     }
 
-    guard let valueAST = valueAST else {
-        return nil
-    }
-
     if let variable = valueAST as? Variable {
         let variableName = variable.name.value
 
@@ -38,7 +34,11 @@ func valueFromAST(valueAST: Value?, type: GraphQLInputType, variables: [String:
         // Note: we're not doing any checking that this variable is correct. We're
         // assuming that this query has been validated and the variable usage here
         // is of the correct type.
-        return variables[variableName]
+        if let variable = variables[variableName] {
+            return variable
+        } else {
+            return .null
+        }
     }
 
     if let list = type as? GraphQLList {
@@ -50,36 +50,38 @@ func valueFromAST(valueAST: Value?, type: GraphQLInputType, variables: [String:
                     valueAST: $0,
                     type: itemType as! GraphQLInputType,
                     variables: variables
-                )!
+                )
             }))
         }
 
-        return try [valueFromAST(valueAST: valueAST, type: itemType as! GraphQLInputType, variables: variables)!]
+        return try [valueFromAST(valueAST: valueAST, type: itemType as! GraphQLInputType, variables: variables)]
     }
 
     if let objectType = type as? GraphQLInputObjectType {
         guard let objectValue = valueAST as? ObjectValue else {
-            return nil
+            throw GraphQLError(message: "Must be object type")
         }
 
         let fields = objectType.fields
-
         let fieldASTs = objectValue.fields.keyMap({ $0.name.value })
 
-        return try .dictionary(fields.keys.reduce([:] as OrderedDictionary<String, Map>) { obj, fieldName in
+        return try .dictionary(fields.keys.reduce(OrderedDictionary<String, Map>()) { obj, fieldName in
             var obj = obj
-            let field = fields[fieldName]
-            let fieldAST = fieldASTs[fieldName]
-            var fieldValue = try valueFromAST(
-                valueAST: fieldAST?.value,
-                type: field!.type,
-                variables: variables
-            )
-
-            if fieldValue == .null {
-                fieldValue = field.flatMap({ $0.defaultValue.map({ .string($0) }) })
-            } else {
+            let field = fields[fieldName]!
+            if let fieldAST = fieldASTs[fieldName] {
+                let fieldValue = try valueFromAST(
+                    valueAST: fieldAST.value,
+                    type: field.type,
+                    variables: variables
+                )
                 obj[fieldName] = fieldValue
+            } else {
+                // If AST doesn't contain field, it is undefined
+                if let defaultValue = field.defaultValue {
+                    obj[fieldName] = defaultValue
+                } else {
+                    obj[fieldName] = .undefined
+                }
             }
 
             return obj
@@ -90,11 +92,6 @@ func valueFromAST(valueAST: Value?, type: GraphQLInputType, variables: [String:
         throw GraphQLError(message: "Must be leaf type")
     }
 
-    let parsed = try type.parseLiteral(valueAST: valueAST)
-
-    guard parsed != .null else {
-        return nil
-    }
-
-    return parsed
+    // If we've made it this far, it should be a literal
+    return try type.parseLiteral(valueAST: valueAST)
 }