Use short timeouts for remote config blob downloads

Sources/Networking/RemoteConfigBlobDownloader.swift

@@ -24,12 +24,23 @@ final class URLSessionRemoteConfigBlobDownloader: RemoteConfigBlobDownloaderType
         case unexpectedStatusCode(Int)
     }
 
+    static let timeout: TimeInterval = 5
+
     private let session: URLSession
 
-    init(session: URLSession = .shared) {
+    init(session: URLSession = URLSession(
+        configuration: URLSessionRemoteConfigBlobDownloader.defaultSessionConfiguration()
+    )) {
         self.session = session
     }
 
+    static func defaultSessionConfiguration() -> URLSessionConfiguration {
+        let configuration = URLSessionConfiguration.default
+        configuration.timeoutIntervalForRequest = Self.timeout
+        configuration.timeoutIntervalForResource = Self.timeout
+        return configuration
+    }
+
     func data(from url: URL) async throws -> Data {
         return try await withCheckedThrowingContinuation { continuation in
             let task = self.session.dataTask(with: url) { data, response, error in

Tests/UnitTests/Networking/RemoteConfig/RemoteConfigBlobFetcherTests.swift

@@ -7,6 +7,8 @@
 
 import Foundation
 import Nimble
+import OHHTTPStubs
+import OHHTTPStubsSwift
 @testable import RevenueCat
 import XCTest
 
@@ -31,6 +33,7 @@ final class RemoteConfigBlobFetcherTests: TestCase {
     }
 
     override func tearDownWithError() throws {
+        HTTPStubs.removeAllStubs()
         self.downloader.cancelAll()
         self.fetcher = nil
         self.sourceProvider = nil
@@ -217,6 +220,39 @@ final class RemoteConfigBlobFetcherTests: TestCase {
         expect(self.blobStore.invokedWriteParameters?.data) == payload
     }
 
+    func testRealDownloaderUsesFiveSecondTimeoutAndRetriesNextSourceAfterTimeout() async {
+        let payload = "timeout fallback payload".asData
+        let ref = Self.ref(for: payload)
+        let primaryURL = Self.templateURL.replacingOccurrences(of: Self.placeholder, with: ref)
+        let backupURL = Self.backupTemplateURL.replacingOccurrences(of: Self.placeholder, with: ref)
+
+        stub(condition: isAbsoluteURLString(primaryURL)) { _ in
+            return HTTPStubsResponse(error: URLError(.timedOut))
+        }
+        stub(condition: isAbsoluteURLString(backupURL)) { _ in
+            return HTTPStubsResponse(
+                data: payload,
+                statusCode: Int32(HTTPStatusCode.success.rawValue),
+                headers: nil
+            )
+        }
+
+        self.sourceProvider = Self.sourceProvider(urls: [
+            Self.templateURL,
+            Self.backupTemplateURL
+        ])
+        self.fetcher = RemoteConfigBlobFetcher(
+            blobStore: self.blobStore,
+            sourceProvider: self.sourceProvider,
+            downloader: URLSessionRemoteConfigBlobDownloader()
+        )
+
+        let result = await self.fetcher.ensureDownloaded(ref: ref)
+
+        expect(result) == true
+        expect(self.blobStore.invokedWriteParameters?.data) == payload
+    }
+
     func testNotFoundDoesNotMarkSourceUnhealthyOrRetryNextSource() async {
         let missingRef = Self.ref(for: "missing blob".asData)