test: Adds non-editing visitor tests

Author: NeedleInAJayStack

Sources/GraphQL/Error/GraphQLError.swift

@@ -197,7 +197,7 @@ extension IndexPath: ExpressibleByArrayLiteral {
     }
 }
 
-public enum IndexPathValue: Codable {
+public enum IndexPathValue: Codable, Equatable {
     case index(Int)
     case key(String)
 
@@ -242,7 +242,7 @@ extension IndexPathValue: CustomStringConvertible {
     }
 }
 
-public protocol IndexPathElement {
+public protocol IndexPathElement: CustomStringConvertible {
     var indexPathValue: IndexPathValue { get }
 }
 

Sources/GraphQL/Language/AST.swift

@@ -2,7 +2,7 @@
  * Contains a range of UTF-8 character offsets and token references that
  * identify the region of the source from which the AST derived.
  */
-public struct Location {
+public struct Location: Equatable {
     /**
      * The character offset at which this Node begins.
      */
@@ -159,6 +159,21 @@ public enum NodeResult {
         }
         return false
     }
+
+    func get(key: IndexPathElement) -> NodeResult? {
+        switch self {
+        case let .node(node):
+            guard let key = key.keyValue else {
+                return nil
+            }
+            return node.get(key: key)
+        case let .array(array):
+            guard let key = key.indexValue else {
+                return nil
+            }
+            return .node(array[key])
+        }
+    }
 }
 
 /**

Sources/GraphQL/Language/Kinds.swift

@@ -1,4 +1,4 @@
-public enum Kind: CaseIterable {
+public enum Kind: String, CaseIterable {
     case name
     case document
     case operationDefinition