咨询将play-services(9.0.1)及FCM(9.0)升级到15.0.x的副作用与测试需求

Hey there! Let's break down your two questions about upgrading Google Play Services from 9.0.1 to 15.0.0 and FCM from 9.0 to 15.0.0, with practical insights tailored to your scenario.

1. What Improvements Does Upgrading FCM to 15.0.0 Bring? #

Upgrading FCM to 15.0.0 delivers tangible enhancements for your messaging workflow:

• Reliable Message Delivery: Google refined the FCM pipeline in newer versions, cutting down on delivery delays and boosting success rates for both foreground and background messages—critical for keeping users engaged.
• Android Oreo+ Notification Compliance: 15.0.0 fully supports Android 8.0's notification channel requirement. If your app targets Oreo or higher, this upgrade ensures push notifications won't get blocked by the system (a common pain point with older FCM versions that lack channel support).
• Streamlined API Workflows: You’ll gain access to more intuitive APIs for topic subscriptions/unsubscriptions, token management, and message customization. For example, handling token refreshes becomes more straightforward with updated callback methods.
• Better Debugging Tools: Newer FCM versions include detailed logging for delivery failures, making it easier to diagnose issues like missing tokens or blocked notifications without digging through obscure logs.
• Independent Versioning: Starting from 15.x, Firebase libraries use independent version numbers (no longer strictly tied to Play Services versions), though aligning both upgrades as you’re doing is totally valid.

2. Potential Side Effects of Play Services Upgrade & Required Testing #

Even though you didn’t find compile-time errors, there are runtime and compatibility risks to watch for, plus key tests you should run to ensure stability:

Potential Side Effects #

• Method Count Bloat: Jumping from 9.0.1 to 15.0.0 might increase your app’s method count. If you haven’t enabled R8/ProGuard, you could hit the 65k method limit—use a tool like Android Studio’s Method Count plugin to check post-upgrade.
• Custom Skin Compatibility Issues: Devices with custom Android skins (Huawei, Xiaomi, etc.) often have outdated system-level Play Services components that can conflict with 15.0.0. This might lead to runtime crashes or failed FCM token retrieval.
• Subtle Permission Adjustments: Even if you’re only using FCM, newer Play Services versions might introduce minor permission changes. Double-check your manifest to ensure all required permissions are present and correctly configured.
• Third-Party Dependency Conflicts: If other libraries in your project rely on older Play Services versions, you could face dependency resolution errors. Run ./gradlew dependencies to audit your dependency tree and ensure all Play Services/Firebase libraries use the same version.

Key Tests to Perform #

• FCM Core Functionality: Test message delivery in all app states: foreground, background, and after the app has been killed. Verify notifications display correctly (with channels on Oreo+), and that tapping notifications opens the intended screen.
• Cross-Device & Version Coverage: Test across your app’s minimum supported Android version up to the latest, plus popular device brands. Pay extra attention to devices with aggressive battery optimization—confirm your app’s notification setup bypasses these restrictions if needed.
• Performance Checks: Monitor app startup time, memory usage, and battery drain post-upgrade. Newer libraries can sometimes add overhead, so ensure there’s no significant degradation.
• Edge Scenarios: Test network switching (WiFi ↔ mobile data), outdated Play Services (your app should prompt users to update), and token refresh failures (verify your app handles token updates correctly).
• Dependency Validation: Run ./gradlew check to catch hidden dependency conflicts or manifest merge issues that might not surface at compile time.

内容的提问来源于stack exchange，提问作者dev90