fix: Adds variable directive support

Author: NeedleInAJayStack

Sources/GraphQL/Language/AST.swift

@@ -401,7 +401,7 @@ public final class OperationDefinition {
             }
             return .array(variableDefinitions)
         case "directives":
-            guard !variableDefinitions.isEmpty else {
+            guard !directives.isEmpty else {
                 return nil
             }
             return .array(directives)
@@ -475,12 +475,20 @@ public final class VariableDefinition {
     public private(set) var variable: Variable
     public private(set) var type: Type
     public private(set) var defaultValue: Value?
+    public private(set) var directives: [Directive]
 
-    init(loc: Location? = nil, variable: Variable, type: Type, defaultValue: Value? = nil) {
+    init(
+        loc: Location? = nil,
+        variable: Variable,
+        type: Type,
+        defaultValue: Value? = nil,
+        directives: [Directive] = []
+    ) {
         self.loc = loc
         self.variable = variable
         self.type = type
         self.defaultValue = defaultValue
+        self.directives = directives
     }
 
     public func get(key: String) -> NodeResult? {
@@ -491,6 +499,11 @@ public final class VariableDefinition {
             return .node(type)
         case "defaultValue":
             return defaultValue.map { .node($0) }
+        case "directives":
+            guard !directives.isEmpty else {
+                return nil
+            }
+            return .array(directives)
         default:
             return nil
         }
@@ -525,6 +538,14 @@ public final class VariableDefinition {
                 return
             }
             self.defaultValue = defaultValue
+        case "directives":
+            guard
+                case let .array(values) = value,
+                let directives = values as? [Directive]
+            else {
+                return
+            }
+            self.directives = directives
         default:
             return
         }

Sources/GraphQL/Language/Parser.swift

@@ -276,7 +276,8 @@ func parseVariableDefinition(lexer: Lexer) throws -> VariableDefinition {
         variable: parseVariable(lexer: lexer),
         type: (expect(lexer: lexer, kind: .colon), parseTypeReference(lexer: lexer)).1,
         defaultValue: skip(lexer: lexer, kind: .equals) ?
-            parseValueLiteral(lexer: lexer, isConst: true) : nil
+            parseValueLiteral(lexer: lexer, isConst: true) : nil,
+        directives: parseDirectives(lexer: lexer)
     )
 }
 

Sources/GraphQL/Language/Printer.swift

@@ -48,8 +48,7 @@ extension OperationDefinition: Printable {
 extension VariableDefinition: Printable {
     var printed: String {
         variable + ": " + type.printed + wrap(" = ", defaultValue?.printed)
-//        + wrap(" ", join(directives, " "))
-        // TODO: variable directives are currently not supported
+            + wrap(" ", join(directives, " "))
     }
 }
 

Sources/GraphQL/Language/Visitor.swift

@@ -3,7 +3,7 @@ let QueryDocumentKeys: [Kind: [String]] = [
 
     .document: ["definitions"],
     .operationDefinition: ["name", "variableDefinitions", "directives", "selectionSet"],
-    .variableDefinition: ["variable", "type", "defaultValue"],
+    .variableDefinition: ["variable", "type", "defaultValue", "directives"],
     .variable: ["name"],
     .selectionSet: ["selections"],
     .field: ["alias", "name", "arguments", "directives", "selectionSet"],

Sources/GraphQL/Type/Directives.swift

@@ -7,6 +7,7 @@ public enum DirectiveLocation: String, Encodable {
     case fragmentDefinition = "FRAGMENT_DEFINITION"
     case fragmentSpread = "FRAGMENT_SPREAD"
     case inlineFragment = "INLINE_FRAGMENT"
+    case variableDefinition = "VARIABLE_DEFINITION"
     // Schema Definitions
     case schema = "SCHEMA"
     case scalar = "SCALAR"
@@ -33,7 +34,7 @@ public struct GraphQLDirective: Encodable {
 
     public init(
         name: String,
-        description: String,
+        description: String = "",
         locations: [DirectiveLocation],
         args: GraphQLArgumentConfigMap = [:]
     ) throws {