Adds GraphQLRequest type

Package.resolved

@@ -6,17 +6,17 @@
         "repositoryURL": "https://github.com/apple/swift-collections",
         "state": {
           "branch": null,
-          "revision": "2d33a0ea89c961dcb2b3da2157963d9c0370347e",
-          "version": "1.0.1"
+          "revision": "48254824bb4248676bf7ce56014ff57b142b77eb",
+          "version": "1.0.2"
         }
       },
       {
         "package": "swift-nio",
         "repositoryURL": "https://github.com/apple/swift-nio.git",
         "state": {
           "branch": null,
-          "revision": "120acb15c39aa3217e9888e515de160378fbcc1e",
-          "version": "2.18.0"
+          "revision": "51c3fc2e4a0fcdf4a25089b288dd65b73df1b0ef",
+          "version": "2.37.0"
         }
       }
     ]

Sources/GraphQL/GraphQLRequest.swift

@@ -0,0 +1,40 @@
+import Foundation
+
+/// A GraphQL request object, containing `query`, `operationName`, and `variables` fields
+public struct GraphQLRequest: Equatable, Codable {
+    public var query: String
+    public var operationName: String?
+    public var variables: [String: Map]
+
+    public init(query: String, operationName: String? = nil, variables: [String: Map] = [:]) {
+        self.query = query
+        self.operationName = operationName
+        self.variables = variables
+    }
+
+    // To handle decoding with a default of variables = []
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        self.query = try container.decode(String.self, forKey: .query)
+        self.operationName = try container.decodeIfPresent(String.self, forKey: .operationName)
+        self.variables = try container.decodeIfPresent([String: Map].self, forKey: .variables) ?? [:]
+    }
+
+    /// Boolean indicating if the GraphQL request is a subscription operation.
+    /// This operation performs an entire AST parse on the GraphQL request, so consider
+    /// performance when calling multiple times.
+    ///
+    /// - Returns: True if request is a subscription, false if it is an atomic operation (like `query` or `mutation`)
+    public func isSubscription() throws -> Bool {
+        let documentAST = try GraphQL.parse(
+            instrumentation: NoOpInstrumentation,
+            source: Source(body: self.query, name: "GraphQL request")
+        )
+        let firstOperation = documentAST.definitions.compactMap { $0 as? OperationDefinition }.first
+        guard let operationType = firstOperation?.operation else {
+            throw GraphQLError(message: "GraphQL operation type could not be determined")
+        }
+        return operationType == .subscription
+    }
+}
+