LeakCanary is a sophisticated memory leak detection library for Android and Java, developed by Square. In production, it integrates into Android applications to automatically monitor object allocations, trigger heap dumps upon detecting suspicious memory growth, and analyze these dumps to identify leaking objects. It provides detailed leak traces showing the reference path from GC roots to the leaking object, helping developers pinpoint the root cause. The project also includes Shark Dive, a powerful desktop application for interactive heap dump exploration using treemap, radial, and stack visualizations, and a CLI tool for batch analysis. The architecture is a multi-module monorepo with a clean separation of concerns. The core analysis engine (shark) is platform-independent, handling HPROF parsing, heap graph construction, dominator tree computation (Lengauer-Tarjan), and shortest path finding. Android-specific modules (leakcanary-android-*) provide lifecycle integration, UI, and notification handling. The desktop app (shark-dive-app) is built with Kotlin Compose UI and features an agent protocol for AI-assisted analysis. The codebase is primarily Kotlin, leveraging Okio for I/O and Gradle for building. The repository exhibits exceptionally high craftsmanship. It implements complex graph algorithms (dominator trees, multi-strength BFS reachability, squarified treemap layout) with clear, well-tested code. It solves hard engineering problems like sorting data larger than 2GB (PagedByteArrayTimSort) and building memory-efficient indexes. While actively maintained, the codebase shows some technical drift with deprecated APIs and TODOs, but the core algorithms and architecture are timeless and robust. It is a prime example of a well-engineered, domain-specific analysis tool.
Tencent/wujie is a production-grade micro-frontend framework that achieves native-level isolation by combining iframe sandboxing for JavaScript execution with Web Components (Shadow DOM) for CSS scoping. Unlike other micro-frontend solutions that rely on JavaScript sandbox polyfills (e.g., 'with' statements), Wujie leverages the browser's built-in iframe security model, making it robust against prototype pollution and global variable conflicts. The framework is implemented as a monorepo containing a core library (wujie-core), framework-specific integrations for Vue 2/3 and React, comprehensive examples, and an extensive test suite. The core provides lifecycle APIs (startApp, preloadApp, destroyApp) and supports multiple running modes: alive (keep-alive), singleton (lifecycle-based), and rebuild (full destroy each time). It includes a plugin system for custom asset loaders (HTML, CSS, JS), routing synchronization between main and sub-apps, and a decentralized EventBus for cross-application communication. The architecture handles degradation gracefully: if Proxy or WebComponent is unavailable, it falls back to a pure iframe with Object.defineProperty-based sandbox. The repository exhibits high craftsmanship in several areas: a dedicated EventCleanupTracker for preventing memory leaks, a custom proxy generator that patches cross-realm instanceof checks, and deferred style loading to support libraries like TinyMCE. Integration and unit tests cover lifecycle, plugins, routing sync, and memory leak scenarios. The accompanying documentation site provides detailed guides and API references. However, the codebase shows signs of maintenance burden: the example sub-apps use outdated frameworks (Angular 12, React 16/17), the integration test setup is complex and slow, and the dense patching of native DOM APIs introduces fragility across browser updates. Overall, it is a well-architected and actively maintained solution for micro-frontend orchestration.