Update HTTP response to be optional until created.

Sources/Apollo/ApolloErrorInterceptor.swift

@@ -9,12 +9,12 @@ public protocol ApolloErrorInterceptor {
   ///   - error: The received error
   ///   - chain: The chain the error was received on
   ///   - request: The request, as far as it was constructed
-  ///   - response: The response, as far as it was constructed
+  ///   - response: [optional] The response, if one was received
   ///   - completion: The completion closure to fire when the operation has completed. Note that if you call `retry` on the chain, you will not want to call the completion block in this method.
   func handleErrorAsync<Operation: GraphQLOperation>(
       error: Error,
       chain: RequestChain,
       request: HTTPRequest<Operation>,
-      response: HTTPResponse<Operation>,
+      response: HTTPResponse<Operation>?,
       completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void)
 }

Sources/Apollo/ApolloInterceptor.swift

@@ -6,11 +6,11 @@ public protocol ApolloInterceptor: class {
   /// - Parameters:
   ///   - chain: The chain the interceptor is a part of.
   ///   - request: The request, as far as it has been constructed
-  ///   - response: The response, as far as it has been constructed
+  ///   - response: [optional] The response, if received
   ///   - completion: The completion block to fire when data needs to be returned to the UI.
   func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void)
 }

Sources/Apollo/AutomaticPersistedQueryInterceptor.swift

@@ -9,7 +9,7 @@ public class AutomaticPersistedQueryInterceptor: ApolloInterceptor {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
 
     guard
@@ -22,7 +22,7 @@ public class AutomaticPersistedQueryInterceptor: ApolloInterceptor {
         return
     }
 
-    guard let result = response.parsedResponse else {
+    guard let result = response?.parsedResponse else {
       // This is in the wrong order - this needs to be parsed before we can check it.
       chain.handleErrorAsync(APQError.noParsedResponse,
                              request: request,

Sources/Apollo/CodableParsingInterceptor.swift

@@ -2,6 +2,7 @@ import Foundation
 
 public enum ParserError: Error {
   case nilData
+  case noResponseToParse
   case couldNotParseToLegacyJSON
 }
 
@@ -18,25 +19,39 @@ public class CodableParsingInterceptor<FlexDecoder: FlexibleDecoder>: ApolloInte
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
     guard !self.isCancelled else {
       return
     }
 
-    guard let data = response.rawData else {
-      completion(.failure(ParserError.nilData))
+    guard let createdResponse = response else {
+      chain.handleErrorAsync(ParserError.noResponseToParse,
+                             request: request,
+                             response: response,
+                             completion: completion)
+      return
+    }
+
+    guard let data = response?.rawData else {
+      chain.handleErrorAsync(ParserError.nilData,
+                             request: request,
+                             response: createdResponse,
+                             completion: completion)
       return
     }
 
     do {
       let parsedData = try GraphQLResult<Operation.Data>(from: data, decoder: self.decoder)
-      response.parsedResponse = parsedData
+      createdResponse.parsedResponse = parsedData
       chain.proceedAsync(request: request,
                          response: response,
                          completion: completion)
     } catch {
-      completion(.failure(error))
+      chain.handleErrorAsync(error,
+                             request: request,
+                             response: createdResponse,
+                             completion: completion)
     }
   }
 }

Sources/Apollo/FinalizingInterceptor.swift

@@ -10,12 +10,12 @@ public class FinalizingInterceptor: ApolloInterceptor {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
 
-    guard let parsed = response.parsedResponse else {
-      chain.handleErrorAsync(FinalizationError.nilParsedValue(httpResponse: response.httpResponse,
-                                                              rawData: response.rawData),
+    guard let parsed = response?.parsedResponse else {
+      chain.handleErrorAsync(FinalizationError.nilParsedValue(httpResponse: response?.httpResponse,
+                                                              rawData: response?.rawData),
                              request: request,
                              response: response,
                              completion: completion)

Sources/Apollo/HTTPResponse.swift

@@ -2,17 +2,17 @@ import Foundation
 
 /// Data about a response received by an HTTP request.
 public class HTTPResponse<Operation: GraphQLOperation> {
-  public var httpResponse: HTTPURLResponse?
+  public var httpResponse: HTTPURLResponse
   public var rawData: Data?
   public var parsedResponse: GraphQLResult<Operation.Data>?
 
   /// Designated initializer
   ///
   /// - Parameters:
-  ///   - response: [optional] The `HTTPURLResponse` received from the server. Will be nil if not yet received or if the response received was not an `HTTPURLResponse`.
-  ///   - rawData: [optional] The raw, unparsed data received from the server. Will be nil if not yet received or if data received from the server was nil.
-  ///   - parsedResponse: [optional] The response parsed into the `ParsedValue` type. Will be nil if not yet received, not yet parsed, or if parsing failed.
-  public init(response: HTTPURLResponse?,
+  ///   - response: The `HTTPURLResponse` received from the server.
+  ///   - rawData: [optional] The raw, unparsed data received from the server. Will be nil if data received from the server was nil.
+  ///   - parsedResponse: [optional] The response parsed into the `ParsedValue` type. Will be nil if not yet parsed, or if parsing failed.
+  public init(response: HTTPURLResponse,
               rawData: Data?,
               parsedResponse: GraphQLResult<Operation.Data>?) {
     self.httpResponse = response

Sources/Apollo/LegacyCacheReadInterceptor.swift

@@ -19,7 +19,7 @@ public class LegacyCacheReadInterceptor: ApolloInterceptor {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
 
     switch request.operation.operationType {

Sources/Apollo/LegacyCacheWriteInterceptor.swift

@@ -15,7 +15,7 @@ public class LegacyCacheWriteInterceptor: ApolloInterceptor {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
 
     guard request.cachePolicy != .fetchIgnoringCacheCompletely else {
@@ -26,7 +26,7 @@ public class LegacyCacheWriteInterceptor: ApolloInterceptor {
       return
     }
 
-    guard let data = response.rawData else {
+    guard let data = response?.rawData else {
       chain.handleErrorAsync(ParserError.nilData,
                              request: request,
                              response: response,

Sources/Apollo/LegacyParsingInterceptor.swift

@@ -6,14 +6,16 @@ public class LegacyParsingInterceptor: ApolloInterceptor {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
 
-    guard let data = response.rawData else {
-      chain.handleErrorAsync(ParserError.nilData,
-                             request: request,
-                             response: response,
-                             completion: completion)
+    guard
+      let createdResponse = response,
+      let data = createdResponse.rawData else {
+        chain.handleErrorAsync(ParserError.nilData,
+                               request: request,
+                               response: response,
+                               completion: completion)
       return
     }
 
@@ -25,11 +27,12 @@ public class LegacyParsingInterceptor: ApolloInterceptor {
 
       let graphQLResponse = GraphQLResponse(operation: request.operation, body: body)
       let parsedResult = try graphQLResponse.parseResultFast()
-      let typedResult = parsedResult    
-      response.parsedResponse = typedResult
+      let typedResult = parsedResult
+
+      createdResponse.parsedResponse = typedResult
 
       chain.proceedAsync(request: request,
-                         response: response,
+                         response: createdResponse,
                          completion: completion)
 
     } catch {

Sources/Apollo/MaxRetryInterceptor.swift

@@ -19,7 +19,7 @@ public class MaxRetryInterceptor: ApolloInterceptor {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
     guard request.retryCount <= self.maxRetries else {
       let error = RetryError.hitMaxRetryCount(count: self.maxRetries,

Sources/Apollo/NetworkFetchInterceptor.swift

@@ -15,7 +15,7 @@ public class NetworkFetchInterceptor: ApolloInterceptor, Cancellable {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
 
     let urlRequest: URLRequest
@@ -45,8 +45,9 @@ public class NetworkFetchInterceptor: ApolloInterceptor, Cancellable {
                                response: response,
                                completion: completion)
       case .success(let (data, httpResponse)):
-        response.httpResponse = httpResponse
-        response.rawData = data
+        let response = HTTPResponse<Operation>(response: httpResponse,
+                                               rawData: data,
+                                               parsedResponse: nil)
         chain.proceedAsync(request: request,
                            response: response,
                            completion: completion)

Sources/Apollo/RequestChain.swift

@@ -44,21 +44,18 @@ public class RequestChain: Cancellable {
     request: HTTPRequest<Operation>,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
     assert(self.currentIndex == 0, "The interceptor index should be zero when calling this method")
-
-    let response: HTTPResponse<Operation> = HTTPResponse(response: nil,
-                                                           rawData: nil,
-                                                           parsedResponse: nil)
+
     guard let firstInterceptor = self.interceptors.first else {
       handleErrorAsync(ChainError.noInterceptors,
                        request: request,
-                       response: response,
+                       response: nil,
                        completion: completion)
       return
     }
 
     firstInterceptor.interceptAsync(chain: self,
                                     request: request,
-                                    response: response,
+                                    response: nil,
                                     completion: completion)
   }
 
@@ -68,9 +65,10 @@ public class RequestChain: Cancellable {
   ///   - request: The in-progress request object
   ///   - response: The in-progress response object
   ///   - completion: The completion closure to call when data has been processed and should be returned to the UI.
-  public func proceedAsync<Operation: GraphQLOperation>(request: HTTPRequest<Operation>,
-                           response: HTTPResponse<Operation>,
-                           completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
+  public func proceedAsync<Operation: GraphQLOperation>(
+    request: HTTPRequest<Operation>,
+    response: HTTPResponse<Operation>?,
+    completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
     guard self.isNotCancelled else {
       // Do not proceed, this chain has been cancelled.
       return
@@ -135,7 +133,7 @@ public class RequestChain: Cancellable {
   public func handleErrorAsync<Operation: GraphQLOperation>(
     _ error: Error,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
     guard self.isNotCancelled else {
       return

Sources/Apollo/ResponseCodeInterceptor.swift

@@ -10,13 +10,14 @@ public class ResponseCodeInterceptor: ApolloInterceptor {
   public func interceptAsync<Operation: GraphQLOperation>(
     chain: RequestChain,
     request: HTTPRequest<Operation>,
-    response: HTTPResponse<Operation>,
+    response: HTTPResponse<Operation>?,
     completion: @escaping (Result<GraphQLResult<Operation.Data>, Error>) -> Void) {
 
-    guard response.httpResponse?.apollo.isSuccessful == true else {
-      let error = ResponseCodeError.invalidResponseCode(response: response.httpResponse,
+
+    guard response?.httpResponse.apollo.isSuccessful == true else {
+      let error = ResponseCodeError.invalidResponseCode(response: response?.httpResponse,
 
-                                                        rawData: response.rawData)
+                                                        rawData: response?.rawData)
 
       chain.handleErrorAsync(error,
                              request: request,