bullet-proofing against nullpointerexceptions for caching

Author: Daggerpov

Spawn-App-iOS-SwiftUI/Services/API/APIService.swift

@@ -905,6 +905,12 @@ class APIService: IAPIService {
 	func validateCache(_ cachedItems: [String: Date]) async throws -> [String: CacheValidationResponse] {
 		resetState()
 
+		// Don't send validation request if there are no cached items to validate
+		if cachedItems.isEmpty {
+			print("No cached items to validate, returning empty response")
+			return [:]
+		}
+		
 		guard let userId = UserAuthViewModel.shared.spawnUser?.id else {
 			throw APIError.invalidData
 		}

Spawn-App-iOS-SwiftUI/Services/API/MockAPIService.swift

@@ -404,6 +404,12 @@ class MockAPIService: IAPIService {
 	func validateCache(_ cachedItems: [String: Date]) async throws -> [String:
 		CacheValidationResponse]
 	{
+		// Don't send validation request if there are no cached items to validate
+		if cachedItems.isEmpty {
+			print("MOCK: No cached items to validate, returning empty response")
+			return [:]
+		}
+		
 		// In the mock implementation, we'll pretend everything is fresh except for items
 		// that are older than 30 minutes
 		var result: [String: CacheValidationResponse] = [:]

Spawn-App-iOS-SwiftUI/Services/AppCache.swift

@@ -70,6 +70,12 @@ class AppCache: ObservableObject {
             return
         }
 
+        // Don't send validation request if we have no cached items to validate
+        if lastChecked.isEmpty {
+            print("No cached items to validate, skipping cache validation")
+            return
+        }
+        
         do {
             let apiService: IAPIService = MockAPIService.isMocking ? MockAPIService(userId: userId) : APIService()
             let result = try await apiService.validateCache(lastChecked)