Monday, September 8, 2025

Web

A JavaScript Event Emitter, or Pub/Sub pattern, is a fundamental concept for managing communication between components or modules. The goal is to build an EventEmitter class with Subscribe, Emit, and Unsubscribe methods, allowing users to attach callbacks to events and execute them when emitted. This design enables flexible event handling in various systems.

Asynchronous JavaScript is crucial in React applications for managing real-world data fetching and user interactions. The author explains how callbacks, Promises, async/await, and AbortController can prevent common mistakes like "callback hell," ensuring reliable code execution. Best practices include using useEffect for async side effects and handling loading/error states to prioritize user experience.

Managing a large codebase with numerous dependencies can be daunting due to potential "dependency hell." Over 200 direct and countless indirect dependencies make updates and security patches a monumental challenge, taking up development time and introducing security risks. Experts recommend strategies like audits, minimalism, and ownership to prevent dependency bloat.

Lean is a functional programming language that focuses on expressing mathematical concepts and proofs through its strong type theory system and recursive data types. Its syntax allows for interleave code and proofs, enabling reuse of known facts about data structures, making it ideal for research, development, verification, and validation applications.

Node.js's streaming architecture enables efficient handling of large file uploads by utilizing buffers and backpressure, preventing servers from crashing due to memory constraints. This approach allows for processing massive files without impacting server performance, making it crucial for applications that handle large datasets or require responsive performance under heavy loads.

A new Go tutorial outlines building a high-performance concurrent live leaderboard that can handle thousands of simultaneous updates while serving frequent Top-N queries efficiently and maintaining predictable snapshots of scores despite concurrent writes. It proposes a sharded map design using local top-N min-heaps for high concurrency and simplicity.

The new testing/synctest package in Go 1.25 simplifies concurrent testing by using a fake clock that only advances when all goroutines are blocked. This allows tests to run faster without compromising reliability. Developers can fix flaky tests with synctest by adding delays or using the Wait function, improving test efficiency and reliability.

A recent update to a synthetic stock price generator service written in Go introduces an extension that generates historical data from a specified start time, feeding it into live data. The author resolves issues with comparing time structs using operators by utilizing the "time" library's Add function, paving the way for upcoming bug fixes and improvements.

The introduction of OKlch as a new color space offers an alternative to traditional sRGB, which struggles to accurately represent human-perceived colors. OKlch uses a three-dimensional coordinate system for optimal lightness, chroma, and hue manipulation, resulting in smoother transitions, improved brightness and saturation consistency, and better browser/display compatibility.