Adds handling for multiple errors

Author: Jay Herron

Sources/GraphQL/Subscription/Subscribe.swift

@@ -53,10 +53,9 @@ func subscribe(
         operationName: operationName
     )
 
-    return sourceFuture.map{ subscriptionResult -> SubscriptionResult in
-        do {
-            let subscriptionObserver = try subscriptionResult.get()
-            let eventObserver = subscriptionObserver.map { eventPayload -> Future<GraphQLResult> in
+    return sourceFuture.map{ sourceResult -> SubscriptionResult in
+        if let sourceObservable = sourceResult.observable {
+            let subscriptionObservable = sourceObservable.map { eventPayload -> Future<GraphQLResult> in
 
                 // For each payload yielded from a subscription, map it over the normal
                 // GraphQL `execute` function, with `payload` as the rootValue.
@@ -78,11 +77,9 @@ func subscribe(
                     operationName: operationName
                 )
             }
-            return SubscriptionResult.success(eventObserver)
-        } catch let graphQLError as GraphQLError {
-            return SubscriptionResult.failure(graphQLError)
-        } catch let error {
-            return SubscriptionResult.failure(GraphQLError(error))
+            return SubscriptionResult(observable: subscriptionObservable)
+        } else {
+            return SubscriptionResult(errors: sourceResult.errors)
         }
     }
 }
@@ -164,9 +161,9 @@ func createSourceEventStream(
             result: nil
         )
 
-        return eventLoopGroup.next().makeSucceededFuture(SourceEventStreamResult.failure(error))
+        return eventLoopGroup.next().makeSucceededFuture(SourceEventStreamResult(errors: [error]))
     } catch {
-        return eventLoopGroup.next().makeSucceededFuture(SourceEventStreamResult.failure(GraphQLError(error)))
+        return eventLoopGroup.next().makeSucceededFuture(SourceEventStreamResult(errors: [GraphQLError(error)]))
     }
 }
 
@@ -192,7 +189,7 @@ func executeSubscription(
     let fieldNode = fieldNodes.first!
 
     guard let fieldDef = getFieldDef(schema: context.schema, parentType: type, fieldAST: fieldNode) else {
-        throw GraphQLError.init(
+        throw GraphQLError(
             message: "`The subscription field '\(fieldNode.name.value)' is not defined.`",
             nodes: fieldNodes
         )
@@ -237,34 +234,56 @@ func executeSubscription(
     let resolvedFuture:Future<Any?>
     switch resolvedFutureOrError {
     case let .failure(error):
-        throw error
+        if let graphQLError = error as? GraphQLError {
+            throw graphQLError
+        } else {
+            throw GraphQLError(error)
+        }
     case let .success(success):
         resolvedFuture = success
     }
     return resolvedFuture.map { resolved -> SourceEventStreamResult in
         if !context.errors.isEmpty {
-            // TODO improve this to return multiple errors if we have them.
-            return SourceEventStreamResult.failure(context.errors.first!)
+            return SourceEventStreamResult(errors: context.errors)
         } else if let error = resolved as? GraphQLError {
-            return SourceEventStreamResult.failure(error)
+            return SourceEventStreamResult(errors: [error])
         } else if let observable = resolved as? SourceEventStreamObservable {
-            return SourceEventStreamResult.success(observable)
+            return SourceEventStreamResult(observable: observable)
         } else if resolved == nil {
-            return SourceEventStreamResult.failure(
+            return SourceEventStreamResult(errors: [
                 GraphQLError(message: "Resolved subscription was nil")
-            )
+            ])
         } else {
             let resolvedObj = resolved as AnyObject
-            return SourceEventStreamResult.failure(
+            return SourceEventStreamResult(errors: [
                 GraphQLError(
                     message: "Subscription field resolver must return SourceEventStreamObservable. Received: '\(resolvedObj)'"
                 )
-            )
+            ])
         }
     }
 }
 
-typealias SubscriptionObservable = Observable<Future<GraphQLResult>>
-typealias SubscriptionResult = Result<SubscriptionObservable, GraphQLError>
+public struct SubscriptionResult {
+    public var observable: SubscriptionObservable?
+    public var errors: [GraphQLError]
+    
+    public init(observable: SubscriptionObservable? = nil, errors: [GraphQLError] = []) {
+        self.observable = observable
+        self.errors = errors
+    }
+}
+public typealias SubscriptionObservable = Observable<Future<GraphQLResult>>
+
+struct SourceEventStreamResult {
+    public var observable: SourceEventStreamObservable?
+    public var errors: [GraphQLError]
+    
+    public init(observable: SourceEventStreamObservable? = nil, errors: [GraphQLError] = []) {
+        self.observable = observable
+        self.errors = errors
+    }
+}
 typealias SourceEventStreamObservable = Observable<Any>
-typealias SourceEventStreamResult = Result<SourceEventStreamObservable, GraphQLError>
+
+

Tests/GraphQLTests/Subscription/SubscriptionTests.swift

@@ -172,9 +172,9 @@ class SubscriptionTests : XCTestCase {
                 """
             )
         ) { error in
-            let graphQlError = error as! GraphQLError
-            XCTAssertEqual(graphQlError.message, "`The subscription field 'unknownField' is not defined.`")
-            XCTAssertEqual(graphQlError.locations, [SourceLocation(line: 2, column: 5)])
+            let graphQLError = error as! GraphQLError
+            XCTAssertEqual(graphQLError.message, "`The subscription field 'unknownField' is not defined.`")
+            XCTAssertEqual(graphQLError.locations, [SourceLocation(line: 2, column: 5)])
         }
     }
 
@@ -203,9 +203,9 @@ class SubscriptionTests : XCTestCase {
                 }
             """)
         ) { error in
-            let graphQlError = error as! GraphQLError
+            let graphQLError = error as! GraphQLError
             XCTAssertEqual(
-                graphQlError.message,
+                graphQLError.message,
                 "Subscription field resolver must return SourceEventStreamObservable. Received: 'test'"
             )
         }
@@ -221,8 +221,8 @@ class SubscriptionTests : XCTestCase {
                     }
                 """)
             ) { error in
-                let graphQlError = error as! GraphQLError
-                XCTAssertEqual(graphQlError.message, "test error")
+                let graphQLError = error as! GraphQLError
+                XCTAssertEqual(graphQLError.message, "test error")
             }
         }
 
@@ -278,9 +278,9 @@ class SubscriptionTests : XCTestCase {
                 ]
             )
         ) { error in
-            let graphQlError = error as! GraphQLError
+            let graphQLError = error as! GraphQLError
             XCTAssertEqual(
-                graphQlError.message,
+                graphQLError.message,
                 "Variable \"$priority\" got invalid value \"meow\".\nExpected type \"Int\", found \"meow\"."
             )
         }
@@ -752,7 +752,7 @@ private func createSubscription(
     variableValues: [String: Map] = [:]
 ) throws -> SubscriptionObservable {
     let document = try parse(source: query)
-    let subscriptionOrError = try subscribe(
+    let result = try subscribe(
         queryStrategy: SerialFieldExecutionStrategy(),
         mutationStrategy: SerialFieldExecutionStrategy(),
         subscriptionStrategy: SerialFieldExecutionStrategy(),
@@ -766,10 +766,9 @@ private func createSubscription(
         operationName: nil
     ).wait()
 
-    switch subscriptionOrError {
-    case .success(let subscription):
-        return subscription
-    case .failure(let error):
-        throw error
+    if let observable = result.observable {
+        return observable
+    } else {
+        throw result.errors.first! // We may have more than one...
     }
 }