From 900e8b1b5ec5eb8c9cd4f7ec5f835756bc6ac22f Mon Sep 17 00:00:00 2001
From: Calvin Cestari <calvin.cestari@gmail.com>
Date: Tue, 7 Nov 2023 11:47:21 -0800
Subject: [PATCH] Sends multipart accept header for all query and mutation
 operations

---
 .../MockOperation.swift                       | 10 -----
 Tests/ApolloTests/RequestChainTests.swift     | 45 +++++++++++--------
 .../Apollo/RequestChainNetworkTransport.swift |  3 +-
 3 files changed, 28 insertions(+), 30 deletions(-)

diff --git a/Tests/ApolloInternalTestHelpers/MockOperation.swift b/Tests/ApolloInternalTestHelpers/MockOperation.swift
index a6d05beab..faef67c5c 100644
--- a/Tests/ApolloInternalTestHelpers/MockOperation.swift
+++ b/Tests/ApolloInternalTestHelpers/MockOperation.swift
@@ -43,16 +43,6 @@ open class MockSubscription<SelectionSet: RootSelectionSet>: MockOperation<Selec
   }
 }
 
-open class MockDeferredQuery<SelectionSet: RootSelectionSet>: MockOperation<SelectionSet>, GraphQLQuery {
-
-  public override class var operationType: GraphQLOperationType { .query }
-  public override class var hasDeferredFragments: Bool { true }
-
-  public static func mock() -> MockDeferredQuery<MockSelectionSet> where SelectionSet == MockSelectionSet {
-    MockDeferredQuery<MockSelectionSet>()
-  }
-}
-
 // MARK: - MockSelectionSets
 
 @dynamicMemberLookup
diff --git a/Tests/ApolloTests/RequestChainTests.swift b/Tests/ApolloTests/RequestChainTests.swift
index f24471196..6b99a66dc 100644
--- a/Tests/ApolloTests/RequestChainTests.swift
+++ b/Tests/ApolloTests/RequestChainTests.swift
@@ -371,7 +371,7 @@ class RequestChainTests: XCTestCase {
     wait(for: [expectation], timeout: 1)
   }
 
-  func test__request__givenDeferredOperation_shouldAddMultipartAcceptHeader() {
+  func test__request__givenQuery_shouldAddMultipartAcceptHeader() {
     let expectation = self.expectation(description: "Request header verified")
 
     let interceptor = RequestTrapInterceptor { request in
@@ -389,14 +389,14 @@ class RequestChainTests: XCTestCase {
       endpointURL: TestURL.mockServer.url
     )
 
-    _ = transport.send(operation: MockDeferredQuery.mock()) { result in
+    _ = transport.send(operation: MockQuery.mock()) { result in
       // noop
     }
 
     wait(for: [expectation], timeout: 1)
   }
 
-  func test__request__givenDeferredOperation_whenTransportInitializedWithAdditionalHeaders_shouldOverwriteOnlyAcceptHeader() {
+  func test__request__givenMutation_shouldAddMultipartAcceptHeader() {
     let expectation = self.expectation(description: "Request header verified")
 
     let interceptor = RequestTrapInterceptor { request in
@@ -406,40 +406,42 @@ class RequestChainTests: XCTestCase {
       }
 
       XCTAssertEqual(header, "multipart/mixed;boundary=\"graphql\";\(MultipartResponseDeferParser.protocolSpec),application/json")
-      XCTAssertNotNil(request.allHTTPHeaderFields?["Random"])
       expectation.fulfill()
     }
 
     let transport = RequestChainNetworkTransport(
       interceptorProvider: MockInterceptorProvider([interceptor]),
-      endpointURL: TestURL.mockServer.url,
-      additionalHeaders: [
-        "Accept": "multipart/mixed",
-        "Random": "still-here"
-      ]
+      endpointURL: TestURL.mockServer.url
     )
 
-    _ = transport.send(operation: MockDeferredQuery.mock()) { result in
+    _ = transport.send(operation: MockMutation.mock()) { result in
       // noop
     }
 
     wait(for: [expectation], timeout: 1)
   }
 
-  func test__request__givenQuery_shouldNotAddMultipartAcceptHeader() {
+  func test__request__givenQuery_whenTransportInitializedWithAdditionalHeaders_shouldOverwriteOnlyAcceptHeader() {
     let expectation = self.expectation(description: "Request header verified")
 
     let interceptor = RequestTrapInterceptor { request in
-      if let header = request.allHTTPHeaderFields?["Accept"] {
-        XCTAssertFalse(header.contains("multipart/mixed"))
+      guard let header = request.allHTTPHeaderFields?["Accept"] else {
+        XCTFail()
+        return
       }
 
+      XCTAssertEqual(header, "multipart/mixed;boundary=\"graphql\";\(MultipartResponseDeferParser.protocolSpec),application/json")
+      XCTAssertNotNil(request.allHTTPHeaderFields?["Random"])
       expectation.fulfill()
     }
 
     let transport = RequestChainNetworkTransport(
       interceptorProvider: MockInterceptorProvider([interceptor]),
-      endpointURL: TestURL.mockServer.url
+      endpointURL: TestURL.mockServer.url,
+      additionalHeaders: [
+        "Accept": "multipart/mixed",
+        "Random": "still-here"
+      ]
     )
 
     _ = transport.send(operation: MockQuery.mock()) { result in
@@ -449,20 +451,27 @@ class RequestChainTests: XCTestCase {
     wait(for: [expectation], timeout: 1)
   }
 
-  func test__request__givenMutation_shouldNotAddMultipartAcceptHeader() {
+  func test__request__givenMutation_whenTransportInitializedWithAdditionalHeaders_shouldOverwriteOnlyAcceptHeader() {
     let expectation = self.expectation(description: "Request header verified")
 
     let interceptor = RequestTrapInterceptor { request in
-      if let header = request.allHTTPHeaderFields?["Accept"] {
-        XCTAssertFalse(header.contains("multipart/mixed"))
+      guard let header = request.allHTTPHeaderFields?["Accept"] else {
+        XCTFail()
+        return
       }
 
+      XCTAssertEqual(header, "multipart/mixed;boundary=\"graphql\";\(MultipartResponseDeferParser.protocolSpec),application/json")
+      XCTAssertNotNil(request.allHTTPHeaderFields?["Random"])
       expectation.fulfill()
     }
 
     let transport = RequestChainNetworkTransport(
       interceptorProvider: MockInterceptorProvider([interceptor]),
-      endpointURL: TestURL.mockServer.url
+      endpointURL: TestURL.mockServer.url,
+      additionalHeaders: [
+        "Accept": "multipart/mixed",
+        "Random": "still-here"
+      ]
     )
 
     _ = transport.send(operation: MockMutation.mock()) { result in
diff --git a/apollo-ios/Sources/Apollo/RequestChainNetworkTransport.swift b/apollo-ios/Sources/Apollo/RequestChainNetworkTransport.swift
index 89984f25d..b60764b2c 100644
--- a/apollo-ios/Sources/Apollo/RequestChainNetworkTransport.swift
+++ b/apollo-ios/Sources/Apollo/RequestChainNetworkTransport.swift
@@ -105,9 +105,8 @@ open class RequestChainNetworkTransport: NetworkTransport {
         name: "Accept",
         value: "multipart/mixed;boundary=\"graphql\";\(MultipartResponseSubscriptionParser.protocolSpec),application/json"
       )
-    }
 
-    if Operation.hasDeferredFragments {
+    } else {
       request.addHeader(
         name: "Accept",
         value: "multipart/mixed;boundary=\"graphql\";\(MultipartResponseDeferParser.protocolSpec),application/json"