test: Comprehensive unit tests for Sub Issue 13 (Client/Upgrade/Differential/Push/Parameter matrix)

[JusterZhu]

Summary

This issue tracks the implementation of Sub Issue 13 from the GeneralUpdate Refactoring Plan v2: Comprehensive Unit Test Coverage.

Scope

Add thorough unit and integration tests covering the following areas:

1. Client ↔ Upgrade Mutual Upgrade Integration

• Client validates versions for both client and upgrade
• ProcessInfo serialization round-trip for IPC
• VersionInfo with all fields (cross-version, forcibly, freeze)
• Version chain sorting by release date
• ConfigurationMapper: Configinfo → GlobalConfigInfo → ProcessInfo mapping

2. Differential Upgrade (Clean → Dirty Full Cycle)

• Full mesh update: generate patches in client context, apply in upgrade context
• Binary file differential (EXE/DLL/image assets)
• Large binary files (100KB+)
• Deeply nested directory structures
• Mixed operations: modified, added, deleted, unchanged simultaneously
• DiffPipeline with parallel/serial/cancellation/progress

3. Event Notification Pipeline (Push Upgrade)

• All 7 event types registration and dispatch
• Push upgrade simulation (server notifies, client receives)
• Multiple listeners for the same event type
• Listener exception isolation
• Forcibly update notification

4. Parameter Matrix Combinations

• UpdateOptions constants accessibility
• Configinfo validation with various auth schemes (Bearer, ApiKey, Basic, HMAC)
• Configinfo with various version formats
• Configinfo with various update URLs
• Full production configuration with all fields
• BlackList configuration variations

5. Real-world Developer Usage Scenarios

• Minimal setup (only required fields)
• Full production setup with all options
• Method chaining (fluent API)
• Precheck/skip callbacks
• Custom option injection
• Silent update configuration

6. StorageManager / Backup Tests

• GetTempDirectory creation
• Backup file copying
• Skip directory filtering

Acceptance Criteria

• All new tests compile and pass on Windows
• Test results: CoreTest 111/112 pass (1 pre-existing failure), DifferentialTest 23/23 pass, ClientCoreTest 115/115 pass
• Tests cover client/upgrade/differential/push/parameter combination scenarios
• Tests written from developer user's actual usage perspective

Related PRs

This is the final Sub Issue (#13) in the refactoring plan. Previous issues:

• PR: Sub Issue 2 - Merge Common + ClientCore + Core into unified GeneralUpdate.Core #312, PR: Sub Issue 1 - Security hardening (SSL fix, HTTP auth, HttpClient pooling) #313, PR: Sub Issue 3 - UpdateOptions config system + extension points #315, PR: Sub Issue 4a - Download abstractions, HttpDownloadExecutor, retry policy #317, PR: Sub Issue 4b - Download orchestrator + status reporting #319, PR: Sub Issue 5 - EventManager thread safety fix #321, PR: Sub Issue 7 - OSS options + mark legacy classes obsolete #324, PR: Sub Issue 8 - BlackListManager Lazy<T> + IBlackListMatcher #326, PR: Sub Issue 9 - BackupConfig + Restore/CleanBackup #328, PR: Sub Issue 10 - IUpdateHooks + UnixPermissionHooks #330, PR: Sub Issue 11+12 - GracefulExit utility #332