Update for Xcode 10 and Swift 4.2 (#2552)

* Update for Xcode 10 and Swift 4.2.

* Revert Travis update.

Source/Request.swift

@@ -102,7 +102,7 @@ open class Request {
     open var task: URLSessionTask? { return delegate.task }
 
     /// The session belonging to the underlying task.
-    open let session: URLSession
+    public let session: URLSession
 
     /// The request sent or to be sent to the server.
     open var request: URLRequest? { return task?.originalRequest }
@@ -184,7 +184,7 @@ open class Request {
     /// - parameter password: The password.
     ///
     /// - returns: A tuple with Authorization header and credential value if encoding succeeds, `nil` otherwise.
-    open static func authorizationHeader(user: String, password: String) -> (key: String, value: String)? {
+    open class func authorizationHeader(user: String, password: String) -> (key: String, value: String)? {
         guard let data = "\(user):\(password)".data(using: .utf8) else { return nil }
 
         let credential = data.base64EncodedString(options: [])

Source/ServerTrustPolicy.swift

@@ -27,7 +27,7 @@ import Foundation
 /// Responsible for managing the mapping of `ServerTrustPolicy` objects to a given host.
 open class ServerTrustPolicyManager {
     /// The dictionary of policies mapped to a particular host.
-    open let policies: [String: ServerTrustPolicy]
+    public let policies: [String: ServerTrustPolicy]
 
     /// Initializes the `ServerTrustPolicyManager` instance with the given policies.
     ///

Source/SessionManager.swift

@@ -45,7 +45,7 @@ open class SessionManager {
 
     /// A default instance of `SessionManager`, used by top-level Alamofire request methods, and suitable for use
     /// directly for any ad hoc requests.
-    open static let `default`: SessionManager = {
+    public static let `default`: SessionManager = {
         let configuration = URLSessionConfiguration.default
         configuration.httpAdditionalHeaders = SessionManager.defaultHTTPHeaders
 
@@ -53,7 +53,7 @@ open class SessionManager {
     }()
 
     /// Creates default values for the "Accept-Encoding", "Accept-Language" and "User-Agent" headers.
-    open static let defaultHTTPHeaders: HTTPHeaders = {
+    public static let defaultHTTPHeaders: HTTPHeaders = {
         // Accept-Encoding HTTP Header; see https://tools.ietf.org/html/rfc7230#section-4.2.3
         let acceptEncoding: String = "gzip;q=1.0, compress;q=0.5"
 
@@ -118,13 +118,13 @@ open class SessionManager {
     }()
 
     /// Default memory threshold used when encoding `MultipartFormData` in bytes.
-    open static let multipartFormDataEncodingMemoryThreshold: UInt64 = 10_000_000
+    public static let multipartFormDataEncodingMemoryThreshold: UInt64 = 10_000_000
 
     /// The underlying session.
-    open let session: URLSession
+    public let session: URLSession
 
     /// The session delegate handling all the task and session delegate callbacks.
-    open let delegate: SessionDelegate
+    public let delegate: SessionDelegate
 
     /// Whether to start requests immediately after being constructed. `true` by default.
     open var startRequestsImmediately: Bool = true

Source/TaskDelegate.swift

@@ -31,7 +31,7 @@ open class TaskDelegate: NSObject {
     // MARK: Properties
 
     /// The serial operation queue used to execute all operations after the task completes.
-    open let queue: OperationQueue
+    public let queue: OperationQueue
 
     /// The data returned by the server.
     public var data: Data? { return nil }

Tests/ResultTests.swift

@@ -400,7 +400,9 @@ class ResultTestCase: BaseTestCase {
         result.withError { string = "\(type(of: $0))" }
 
         // Then
-    #if swift(>=3.2)
+    #if swift(>=4.2)
+        XCTAssertEqual(string, "ResultError")
+    #elseif swift(>=3.2)
         XCTAssertEqual(string, "ResultError #1")
     #else
         XCTAssertEqual(string, "(ResultError #1)")