Refactor Nostr ID Bridge & Keychain Helper (#796)

* Extract each type to a separate file

* Nostr ID Bridge: Convert static func/vars to instance

* `KeychainHelper` behind a protocol to easily mock

* Update tests with ID Bridge and MockKeychainHelper

---------

Co-authored-by: jack <212554440+jackjackbits@users.noreply.github.com>

bitchatTests/Fragmentation/FragmentationTests.swift

@@ -15,15 +15,21 @@ struct FragmentationTests {
     
     private let mockKeychain: MockKeychain
     private let mockIdentityManager: MockIdentityManager
+    private let idBridge: NostrIdentityBridge
     
     init() {
         mockKeychain = MockKeychain()
         mockIdentityManager = MockIdentityManager(mockKeychain)
+        idBridge = NostrIdentityBridge(keychain: MockKeychainHelper())
     }
     
     @Test("Reassembly from fragments delivers a public message")
     func reassemblyFromFragmentsDeliversPublicMessage() async throws {
-        let ble = BLEService(keychain: mockKeychain, identityManager: mockIdentityManager)
+        let ble = BLEService(
+            keychain: mockKeychain,
+            idBridge: idBridge,
+            identityManager: mockIdentityManager
+        )
         let capture = CaptureDelegate()
         ble.delegate = capture
         
@@ -55,7 +61,11 @@ struct FragmentationTests {
     
     @Test("Duplicate fragment does not break reassembly")
     func duplicateFragmentDoesNotBreakReassembly() async throws {
-        let ble = BLEService(keychain: mockKeychain, identityManager: mockIdentityManager)
+        let ble = BLEService(
+            keychain: mockKeychain,
+            idBridge: idBridge,
+            identityManager: mockIdentityManager
+        )
         let capture = CaptureDelegate()
         ble.delegate = capture
         
@@ -85,7 +95,11 @@ struct FragmentationTests {
     
     @Test("Invalid fragment header is ignored")
     func invalidFragmentHeaderIsIgnored() async throws {
-        let ble = BLEService(keychain: mockKeychain, identityManager: mockIdentityManager)
+        let ble = BLEService(
+            keychain: mockKeychain,
+            idBridge: idBridge,
+            identityManager: mockIdentityManager
+        )
         let capture = CaptureDelegate()
         ble.delegate = capture
         

bitchatTests/LocationChannelsTests.swift

@@ -37,9 +37,10 @@ final class LocationChannelsTests: XCTestCase {
 
     func testPerGeohashIdentityDeterministic() throws {
         // Derive twice for same geohash; should be identical
+        let idBridge = NostrIdentityBridge(keychain: MockKeychainHelper())
         let gh = "u4pruy"
-        let id1 = try NostrIdentityBridge.deriveIdentity(forGeohash: gh)
-        let id2 = try NostrIdentityBridge.deriveIdentity(forGeohash: gh)
+        let id1 = try idBridge.deriveIdentity(forGeohash: gh)
+        let id2 = try idBridge.deriveIdentity(forGeohash: gh)
         XCTAssertEqual(id1.publicKeyHex, id2.publicKeyHex)
     }
 }

bitchatTests/Mocks/MockKeychain.swift

@@ -44,3 +44,21 @@ final class MockKeychain: KeychainManagerProtocol {
         storage["identity_noiseStaticKey"] != nil
     }
 }
+
+final class MockKeychainHelper: KeychainHelperProtocol {
+    private typealias Service = String
+    private typealias Key = String
+    private var storage: [Service: [Key: Data]] = [:]
+    
+    func save(key: String, data: Data, service: String, accessible: CFString?) {
+        storage[service]?[key] = data
+    }
+    
+    func load(key: String, service: String) -> Data? {
+        storage[service]?[key]
+    }
+    
+    func delete(key: String, service: String) {
+        storage[service]?.removeValue(forKey: key)
+    }
+}