Allow toggle of cache policy used in 'perform' method

Apollo.xcodeproj/project.pbxproj

@@ -257,6 +257,7 @@
 		C35D43C622DDE28D00BCBABE /* a.txt in Resources */ = {isa = PBXBuildFile; fileRef = C304EBD322DDC7B200748F72 /* a.txt */; };
 		C377CCA922D798BD00572E03 /* GraphQLFile.swift in Sources */ = {isa = PBXBuildFile; fileRef = C377CCA822D798BD00572E03 /* GraphQLFile.swift */; };
 		C377CCAB22D7992E00572E03 /* MultipartFormData.swift in Sources */ = {isa = PBXBuildFile; fileRef = C377CCAA22D7992E00572E03 /* MultipartFormData.swift */; };
+		D87AC09F2564D60B0079FAA5 /* ApolloClientOperationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D87AC09E2564D60B0079FAA5 /* ApolloClientOperationTests.swift */; };
 		D90F1AFB2479E57A007A1534 /* WebSocketTransportTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D90F1AF92479DEE5007A1534 /* WebSocketTransportTests.swift */; };
 		E86D8E05214B32FD0028EFE1 /* JSONTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = E86D8E03214B32DA0028EFE1 /* JSONTests.swift */; };
 		F16D083C21EF6F7300C458B8 /* QueryFromJSONBuildingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = F16D083B21EF6F7300C458B8 /* QueryFromJSONBuildingTests.swift */; };
@@ -802,6 +803,7 @@
 		C35D43BF22DDD3C100BCBABE /* c.txt */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = c.txt; sourceTree = "<group>"; };
 		C377CCA822D798BD00572E03 /* GraphQLFile.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GraphQLFile.swift; sourceTree = "<group>"; };
 		C377CCAA22D7992E00572E03 /* MultipartFormData.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MultipartFormData.swift; sourceTree = "<group>"; };
+		D87AC09E2564D60B0079FAA5 /* ApolloClientOperationTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ApolloClientOperationTests.swift; sourceTree = "<group>"; };
 		D90F1AF92479DEE5007A1534 /* WebSocketTransportTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WebSocketTransportTests.swift; sourceTree = "<group>"; };
 		E86D8E03214B32DA0028EFE1 /* JSONTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = JSONTests.swift; sourceTree = "<group>"; };
 		F16D083B21EF6F7300C458B8 /* QueryFromJSONBuildingTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QueryFromJSONBuildingTests.swift; sourceTree = "<group>"; };
@@ -1580,6 +1582,7 @@
 			children = (
 				9B0417812390320A00C9EC4E /* TestHelpers */,
 				9FC750551D2A532D00458D91 /* Info.plist */,
+				D87AC09E2564D60B0079FAA5 /* ApolloClientOperationTests.swift */,
 				F82E62E022BCD223000C311B /* AutomaticPersistedQueriesTests.swift */,
 				9F438D0B1E6C494C007BDC1A /* BatchedLoadTests.swift */,
 				9FC9A9C71E2EFE6E0023C4D5 /* CacheKeyForFieldTests.swift */,
@@ -2653,6 +2656,7 @@
 				C3279FC72345234D00224790 /* TestCustomRequestBodyCreator.swift in Sources */,
 				9B95EDC022CAA0B000702BB2 /* GETTransformerTests.swift in Sources */,
 				9FF90A6F1DDDEB420034C3B6 /* InputValueEncodingTests.swift in Sources */,
+				D87AC09F2564D60B0079FAA5 /* ApolloClientOperationTests.swift in Sources */,
 				9FE1C6E71E634C8D00C02284 /* PromiseTests.swift in Sources */,
 				9B64F6762354D219002D1BB5 /* URL+QueryDict.swift in Sources */,
 				9FADC8541E6B86D900C677E6 /* DataLoaderTests.swift in Sources */,

Sources/Apollo/ApolloClient.swift

@@ -110,14 +110,18 @@ extension ApolloClient: ApolloClientProtocol {
 
   @discardableResult
   public func perform<Mutation: GraphQLMutation>(mutation: Mutation,
+                                                 publishResultToStore: Bool = true,
                                                  queue: DispatchQueue = .main,
                                                  resultHandler: GraphQLResultHandler<Mutation.Data>? = nil) -> Cancellable {
-    return self.networkTransport.send(operation: mutation,
-                                      cachePolicy: .default,
-                                      contextIdentifier: nil,
-                                      callbackQueue: queue) { result in
-       resultHandler?(result)
-    }
+    return self.networkTransport.send(
+      operation: mutation,
+      cachePolicy: publishResultToStore ? .default : .fetchIgnoringCacheCompletely,
+      contextIdentifier: nil,
+      callbackQueue: queue,
+      completionHandler: { result in
+        resultHandler?(result)
+      }
+    )
   }
 
   @discardableResult

Sources/Apollo/ApolloClientProtocol.swift

@@ -47,10 +47,12 @@ public protocol ApolloClientProtocol: class {
   ///
   /// - Parameters:
   ///   - mutation: The mutation to perform.
+  ///   - publishResultToStore: If `true`, this will publish the result returned from the operation to the cache store. Default is `true`.
   ///   - queue: A dispatch queue on which the result handler will be called. Defaults to the main queue.
   ///   - resultHandler: An optional closure that is called when mutation results are available or when an error occurs.
   /// - Returns: An object that can be used to cancel an in progress mutation.
   func perform<Mutation: GraphQLMutation>(mutation: Mutation,
+                                          publishResultToStore: Bool,
                                           queue: DispatchQueue,
                                           resultHandler: GraphQLResultHandler<Mutation.Data>?) -> Cancellable
 

Sources/ApolloTestSupport/XCTestCase+Helpers.swift

@@ -58,7 +58,12 @@ public protocol StoreLoading {
 }
 
 extension StoreLoading where Self: XCTestCase {
-  public func loadFromStore<Query: GraphQLQuery>(query: Query, file: StaticString = #filePath, line: UInt = #line, resultHandler: @escaping AsyncResultObserver<GraphQLResult<Query.Data>, Error>.ResultHandler) {
+  public func loadFromStore<Operation: GraphQLOperation>(
+    query: Operation,
+    file: StaticString = #filePath,
+    line: UInt = #line,
+    resultHandler: @escaping AsyncResultObserver<GraphQLResult<Operation.Data>, Error>.ResultHandler
+  ) {
     let resultObserver = makeResultObserver(for: query, file: file, line: line)
 
     let expectation = resultObserver.expectation(description: "Loaded query from store", file: file, line: line, resultHandler: resultHandler)

Tests/ApolloTests/ApolloClientOperationTests.swift

@@ -0,0 +1,74 @@
+import Apollo
+import ApolloTestSupport
+import StarWarsAPI
+import XCTest
+
+final class ApolloClientOperationTests: XCTestCase, CacheDependentTesting, StoreLoading {
+  var cacheType: TestCacheProvider.Type { InMemoryTestCacheProvider.self }
+
+  var defaultWaitTimeout: TimeInterval { 1 }
+
+  var cache: NormalizedCache!
+  var store: ApolloStore!
+  var server: MockGraphQLServer!
+  var client: ApolloClient!
+
+  override func setUpWithError() throws {
+    try super.setUpWithError()
+
+    self.cache = try self.makeNormalizedCache()
+    self.store = ApolloStore(cache: cache)
+    self.server = MockGraphQLServer()
+    self.client = ApolloClient(
+      networkTransport: MockNetworkTransport(server: self.server, store: self.store),
+      store: self.store
+    )
+  }
+
+  override func tearDownWithError() throws {
+    self.cache = nil
+    self.server = nil
+    self.client = nil
+
+    try super.tearDownWithError()
+  }
+
+  func testPerformMutationRespectsPublishResultToStoreBoolean() throws {
+    let mutation = CreateReviewForEpisodeMutation(episode: .newhope, review: .init(stars: 3))
+    let resultObserver = self.makeResultObserver(for: mutation)
+
+    let serverRequestExpectation = self.server.expect(CreateReviewForEpisodeMutation.self) { _ in
+      [
+        "data": [
+          "createReview": [
+            "__typename": "Review",
+            "stars": 3,
+            "commentary": ""
+          ]
+        ]
+      ]
+    }
+    let performResultFromServerExpectation = resultObserver.expectation(description: "Mutation was successful") { _ in }
+
+    self.client.perform(mutation: mutation, publishResultToStore: false, resultHandler: resultObserver.handler)
+
+    self.loadFromStore(query: mutation) {
+      try XCTAssertFailureResult($0) { error in
+        switch error as? JSONDecodingError {
+        // expected case, nothing to do
+        case .missingValue:
+          break
+
+        // unexpected error, rethrow
+        case .none:
+          throw error
+
+        default:
+          XCTFail("Unexpected json error: \(error)")
+        }
+      }
+    }
+
+    self.wait(for: [serverRequestExpectation, performResultFromServerExpectation], timeout: self.defaultWaitTimeout)
+  }
+}