From 5e5be776766d0a9eb4808e84c870685118954a21 Mon Sep 17 00:00:00 2001
From: Lily Vulcano <millenomi@apple.com>
Date: Thu, 23 May 2019 12:29:30 -0700
Subject: [PATCH] =?UTF-8?q?Parity:=20URLSession.reset(=E2=80=A6)/.flush(?=
 =?UTF-8?q?=E2=80=A6)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Implement reset(…) and flush(…) per their contracts. Note that URLCredentialStorage is unimplemented right now; invoking reset(…) will thus crash if a credentials storage is set.

Ensure that URLSessionConfiguration users do not attempt to use init(), leading to non-portable code.
---
 Foundation/URLSession/URLSession.swift        | 26 +++++++++++++++--
 .../URLSession/URLSessionConfiguration.swift  | 29 +++++++++++++++++--
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/Foundation/URLSession/URLSession.swift b/Foundation/URLSession/URLSession.swift
index e75a2f80b3..7b14c457db 100644
--- a/Foundation/URLSession/URLSession.swift
+++ b/Foundation/URLSession/URLSession.swift
@@ -346,9 +346,31 @@ open class URLSession : NSObject {
         }
     }
     
-    open func reset(completionHandler: @escaping () -> Void) { NSUnimplemented() } /* empty all cookies, cache and credential stores, removes disk files, issues -flushWithCompletionHandler:. Invokes completionHandler() on the delegate queue if not nil. */
+    /* empty all cookies, cache and credential stores, removes disk files, issues -flushWithCompletionHandler:. Invokes completionHandler() on the delegate queue. */
+    open func reset(completionHandler: @escaping () -> Void) {
+        let configuration = self.configuration
+        
+        DispatchQueue.global(qos: .background).async {
+            configuration.urlCache?.removeAllCachedResponses()
+            if let storage = configuration.urlCredentialStorage {
+                for credentialEntry in storage.allCredentials {
+                    for credential in credentialEntry.value {
+                        storage.remove(credential.value, for: credentialEntry.key)
+                    }
+                }
+            }
+            
+            self.flush(completionHandler: completionHandler)
+        }
+    }
     
-    open func flush(completionHandler: @escaping () -> Void)  { NSUnimplemented() }/* flush storage to disk and clear transient network caches.  Invokes completionHandler() on the delegate queue if not nil. */
+     /* flush storage to disk and clear transient network caches.  Invokes completionHandler() on the delegate queue. */
+    open func flush(completionHandler: @escaping () -> Void) {
+        // We create new CURL handles every request.
+        delegateQueue.addOperation {
+            completionHandler()
+        }
+    }
 
     /* invokes completionHandler with outstanding data, upload and download tasks. */
     open func getTasksWithCompletionHandler(completionHandler: @escaping ([URLSessionDataTask], [URLSessionUploadTask], [URLSessionDownloadTask]) -> Void)  {
diff --git a/Foundation/URLSession/URLSessionConfiguration.swift b/Foundation/URLSession/URLSessionConfiguration.swift
index 46c9bafdc3..9ce89de4c6 100644
--- a/Foundation/URLSession/URLSessionConfiguration.swift
+++ b/Foundation/URLSession/URLSessionConfiguration.swift
@@ -36,6 +36,8 @@ import Foundation
 /// A background session can be used to perform networking operations
 /// on behalf of a suspended application, within certain constraints.
 open class URLSessionConfiguration : NSObject, NSCopying {
+    // -init is silently incorrect in URLSessionCofiguration on the desktop. Ensure code that relied on swift-corelibs-foundation's init() being functional is redirected to the appropriate cross-platform class property.
+    @available(*, deprecated, message: "Use .default instead.", renamed: "URLSessionConfiguration.default")
     public override init() {
         self.requestCachePolicy = .useProtocolCachePolicy
         self.timeoutIntervalForRequest = 60
@@ -55,6 +57,27 @@ open class URLSessionConfiguration : NSObject, NSCopying {
         super.init()
     }
     
+    internal convenience init(correctly: ()) {
+        self.init(identifier: nil,
+                  requestCachePolicy: .useProtocolCachePolicy,
+                  timeoutIntervalForRequest: 60,
+                  timeoutIntervalForResource: 604800,
+                  networkServiceType: .default,
+                  allowsCellularAccess: true,
+                  isDiscretionary: false,
+                  connectionProxyDictionary: nil,
+                  httpShouldUsePipelining: false,
+                  httpShouldSetCookies: true,
+                  httpCookieAcceptPolicy: .onlyFromMainDocumentDomain,
+                  httpAdditionalHeaders: nil,
+                  httpMaximumConnectionsPerHost: 6,
+                  httpCookieStorage: .shared,
+                  urlCredentialStorage: nil, // Should be .shared once implemented.
+                  urlCache: nil,
+                  shouldUseExtendedBackgroundIdleMode: false,
+                  protocolClasses: [_HTTPURLProtocol.self, _FTPURLProtocol.self])
+    }
+    
     private init(identifier: String?,
                  requestCachePolicy: URLRequest.CachePolicy,
                  timeoutIntervalForRequest: TimeInterval,
@@ -121,15 +144,15 @@ open class URLSessionConfiguration : NSObject, NSCopying {
     }
     
     open class var `default`: URLSessionConfiguration {
-        return URLSessionConfiguration()
+        return URLSessionConfiguration(correctly: ())
     }
 
     open class var ephemeral: URLSessionConfiguration {
         // Return a new ephemeral URLSessionConfiguration every time this property is invoked
         // TODO: urlCache and urlCredentialStorage should also be ephemeral/in-memory
         // URLCache and URLCredentialStorage are still unimplemented
-        let ephemeralConfiguration = URLSessionConfiguration()
-        ephemeralConfiguration.httpCookieStorage = HTTPCookieStorage.ephemeralStorage()
+        let ephemeralConfiguration = URLSessionConfiguration.default.copy() as! URLSessionConfiguration
+        ephemeralConfiguration.httpCookieStorage = .ephemeralStorage()
         return ephemeralConfiguration
     }