Add tests for Bundle swizzling to prevent recursion in localizedString

Author: serhii-londar

Sources/Tests/Core/BundleSwizzleReentrancyTests.swift

@@ -0,0 +1,146 @@
+//
+//  BundleSwizzleReentrancyTests.swift
+//  CrowdinSDK-Unit-Core_Tests
+//
+//  Validates that swizzled Bundle.localizedString avoids recursion when system APIs
+//  like NSError.localizedDescription trigger nested localization during resolution.
+//
+
+import XCTest
+@testable import CrowdinSDK
+
+private class DummyLocalStorage: LocalLocalizationStorageProtocol {
+    var localization: String
+    var localizations: [String] { [] }
+    var strings: [String : String] = [:]
+    var plurals: [AnyHashable : Any] = [:]
+
+    init(localization: String) {
+        self.localization = localization
+    }
+
+    func fetchData(completion: LocalizationStorageCompletion, errorHandler: LocalizationStorageError?) {
+        completion(localizations, localization, strings, plurals)
+    }
+
+    func saveLocalizaion(strings: [String : String]?, plurals: [AnyHashable : Any]?, for localization: String) { }
+    func save() { }
+    func fetchData() { }
+    func deintegrate() { }
+}
+
+private class DummyRemoteStorage: RemoteLocalizationStorageProtocol {
+    var localization: String
+    var localizations: [String] = []
+    var name: String = "DummyRemoteStorage"
+
+    init(localization: String) {
+        self.localization = localization
+    }
+
+    func prepare(with completion: @escaping () -> Void) { completion() }
+
+    func fetchData(completion: @escaping LocalizationStorageCompletion, errorHandler: LocalizationStorageError?) {
+        completion(localizations, localization, [:], [:])
+    }
+
+    func deintegrate() { }
+}
+
+private class ReentrantProvider: LocalizationProviderProtocol {
+    var localStorage: LocalLocalizationStorageProtocol
+    var remoteStorage: RemoteLocalizationStorageProtocol
+    var localization: String
+    var localizations: [String] { [] }
+
+    required init(localization: String, localStorage: LocalLocalizationStorageProtocol, remoteStorage: RemoteLocalizationStorageProtocol) {
+        self.localization = localization
+        self.localStorage = localStorage
+        self.remoteStorage = remoteStorage
+    }
+
+    func refreshLocalization() { }
+    func refreshLocalization(completion: @escaping ((Error?) -> Void)) { completion(nil) }
+    func prepare(with completion: @escaping () -> Void) { completion() }
+    func deintegrate() { }
+
+    func localizedString(for key: String) -> String? {
+        // Force a direct recursive path through the swizzled method
+        _ = Bundle.main.localizedString(forKey: "__reentrancy_inner__", value: nil, table: nil)
+        return nil
+    }
+
+    func key(for string: String) -> String? { nil }
+    func values(for string: String, with format: String) -> [Any]? { nil }
+    func set(string: String, for key: String) { }
+}
+
+private class NSErrorReentrantProvider: LocalizationProviderProtocol {
+    var localStorage: LocalLocalizationStorageProtocol
+    var remoteStorage: RemoteLocalizationStorageProtocol
+    var localization: String
+    var localizations: [String] { [] }
+
+    required init(localization: String, localStorage: LocalLocalizationStorageProtocol, remoteStorage: RemoteLocalizationStorageProtocol) {
+        self.localization = localization
+        self.localStorage = localStorage
+        self.remoteStorage = remoteStorage
+    }
+
+    func refreshLocalization() { }
+    func refreshLocalization(completion: @escaping ((Error?) -> Void)) { completion(nil) }
+    func prepare(with completion: @escaping () -> Void) { completion() }
+    func deintegrate() { }
+
+    func localizedString(for key: String) -> String? {
+        // Trigger system error description which internally performs localized string lookup
+        _ = NSError(domain: "test-domain", code: 999, userInfo: nil).localizedDescription
+        return nil
+    }
+
+    func key(for string: String) -> String? { nil }
+    func values(for string: String, with format: String) -> [Any]? { nil }
+    func set(string: String, for key: String) { }
+}
+
+class BundleSwizzleReentrancyTests: XCTestCase {
+    override func tearDown() {
+        Bundle.unswizzle()
+        Localization.current = nil
+    }
+
+    func testSwizzledBundleLocalizedStringDoesNotRecurseOnNSError() {
+        Bundle.swizzle()
+        defer {
+            Bundle.unswizzle()
+            Localization.current = nil
+        }
+
+        let local = DummyLocalStorage(localization: "en")
+        let remote = DummyRemoteStorage(localization: "en")
+        let provider = ReentrantProvider(localization: "en", localStorage: local, remoteStorage: remote)
+        Localization.current = Localization(provider: provider)
+
+        // If recursion occurs, this would crash; with the guard it should safely return the key
+        let key = "__reentrancy_test_key__"
+        let value = Bundle.main.localizedString(forKey: key, value: nil, table: nil)
+        XCTAssertEqual(value, key)
+    }
+
+    func testSwizzledBundleLocalizedStringHandlesNSErrorReentrancy() {
+        Bundle.swizzle()
+        defer {
+            Bundle.unswizzle()
+            Localization.current = nil
+        }
+
+        let local = DummyLocalStorage(localization: "en")
+        let remote = DummyRemoteStorage(localization: "en")
+        let provider = NSErrorReentrantProvider(localization: "en", localStorage: local, remoteStorage: remote)
+        Localization.current = Localization(provider: provider)
+
+        let key = "__nserror_reentrancy_test_key__"
+        let value = Bundle.main.localizedString(forKey: key, value: nil, table: nil)
+        XCTAssertEqual(value, key)
+    }
+}

Tests/Tests.xcodeproj/project.pbxproj

@@ -404,14 +404,10 @@
 			inputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-Tests/Pods-Tests-frameworks-${CONFIGURATION}-input-files.xcfilelist",
 			);
-			inputPaths = (
-			);
 			name = "[CP] Embed Pods Frameworks";
 			outputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-Tests/Pods-Tests-frameworks-${CONFIGURATION}-output-files.xcfilelist",
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-Tests/Pods-Tests-frameworks.sh\"\n";