feat: add requestFactory to Configuration

Sources/Segment/Configuration.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if os(Linux)
+import FoundationNetworking
+#endif
 
 public typealias AdvertisingIdCallback = () -> String?
 
@@ -30,8 +33,10 @@ public class Configuration {
         var autoAddSegmentDestination: Bool = true
         var apiHost: String = HTTPClient.getDefaultAPIHost()
         var cdnHost: String = HTTPClient.getDefaultCDNHost()
-        var errorHandler: ((Error) -> Void)?
+        var requestFactory: ((URLRequest) -> URLRequest)? = nil
+        var errorHandler: ((Error) -> Void)? = nil
     }
+
     internal var values: Values
 
     public init(writeKey: String) {
@@ -97,6 +102,12 @@ public extension Configuration {
         return self
     }
 
+    @discardableResult
+    func requestFactory(_ value: @escaping (URLRequest) -> URLRequest) -> Configuration {
+        values.requestFactory = value
+        return self
+    }
+
     @discardableResult
     func errorHandler(_ value: @escaping (Error) -> Void) -> Configuration {
         values.errorHandler = value

Sources/Segment/Utilities/HTTPClient.swift

@@ -70,10 +70,9 @@ public class HTTPClient {
             completion(.failure(HTTPClientErrors.failedToOpenBatch))
             return nil
         }
-
-        var urlRequest = URLRequest(url: uploadURL)
-        urlRequest.httpMethod = "POST"
-
+
+        let urlRequest = configuredRequest(for: uploadURL, method: "POST")
+
         let dataTask = session.uploadTask(with: urlRequest, fromFile: batch) { [weak self] (data, response, error) in
             if let error = error {
                 self?.analytics?.log(message: "Error uploading request \(error.localizedDescription).")
@@ -106,9 +105,8 @@ public class HTTPClient {
             return
         }
 
-        var urlRequest = URLRequest(url: settingsURL)
-        urlRequest.httpMethod = "GET"
-
+        let urlRequest = configuredRequest(for: settingsURL, method: "GET")
+
         let dataTask = session.dataTask(with: urlRequest) { [weak self] (data, response, error) in
             if let error = error {
                 self?.analytics?.reportInternalError(AnalyticsError.networkUnknown(error))
@@ -169,15 +167,24 @@ extension HTTPClient {
         return Self.defaultCDNHost
     }
 
+    internal func configuredRequest(for url: URL, method: String) -> URLRequest {
+        var request = URLRequest(url: url, cachePolicy: .reloadIgnoringLocalCacheData, timeoutInterval: 60)
+        request.httpMethod = method
+        request.addValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
+        request.addValue("Basic \(apiKey)", forHTTPHeaderField: "Authorization")
+        request.addValue("analytics-ios/\(Analytics.version())", forHTTPHeaderField: "User-Agent")
+        request.addValue("gzip", forHTTPHeaderField: "Accept-Encoding")
+
+        if let requestFactory = analytics?.configuration.values.requestFactory {
+            request = requestFactory(request)
+        }
+
+        return request
+    }
+
     internal static func configuredSession(for writeKey: String) -> URLSession {
         let configuration = URLSessionConfiguration.ephemeral
-        configuration.allowsCellularAccess = true
-        configuration.timeoutIntervalForResource = 30
-        configuration.timeoutIntervalForRequest = 60
         configuration.httpMaximumConnectionsPerHost = 2
-        configuration.httpAdditionalHeaders = ["Content-Type": "application/json; charset=utf-8",
-                                               "Authorization": "Basic \(Self.authorizationHeaderForWriteKey(writeKey))",
-                                               "User-Agent": "analytics-ios/\(Analytics.version())"]
         let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: nil)
         return session
     }

Tests/Segment-Tests/Analytics_Tests.swift

@@ -531,4 +531,27 @@ final class Analytics_Tests: XCTestCase {
         XCTAssertEqual(metadata?.bundled, ["Mixpanel"])
         XCTAssertEqual(metadata?.unbundled.sorted(), ["Amplitude", "Customer.io", "dest1"])
     }
+
+    func testRequestFactory() {
+        let config = Configuration(writeKey: "test").requestFactory { request in
+            XCTAssertEqual(request.value(forHTTPHeaderField: "Accept-Encoding"), "gzip")
+            XCTAssertEqual(request.value(forHTTPHeaderField: "Content-Type"), "application/json; charset=utf-8")
+            XCTAssertEqual(request.value(forHTTPHeaderField: "Authorization"), "Basic test")
+            XCTAssertTrue(request.value(forHTTPHeaderField: "User-Agent")!.contains("analytics-ios/"))
+            return request
+        }.errorHandler { error in
+            XCTFail("\(error)")
+        }
+        let analytics = Analytics(configuration: config)
+        let outputReader = OutputReaderPlugin()
+        analytics.add(plugin: outputReader)
+
+        waitUntilStarted(analytics: analytics)
+
+        analytics.track(name: "something")
+
+        analytics.flush()
+
+        RunLoop.main.run(until: Date(timeIntervalSinceNow: 5))
+    }
 }