v2.0.0-alpha.2

[sathvikc]

Lume.js v2.0.0-alpha.2 Release Notes

Release Date: January 14, 2026

🎉 What's New

🔌 Explicit Effect Dependencies & Debugging Tools

Lume.js v2.0.0-alpha.2 brings significant enhancements to developer experience and control. We've introduced "Explicit Mode" for effects to give you fine-grained control over reactivity, a powerful new Debug Addon for inspecting your stores, and major performance optimizations for DOM binding.

👉 Explore the new Effect docs: docs/api/core/effect.md

🏆 Highlights

• Explicit Effects: Dual-mode effect() support (Auto-tracking vs Explicit Tuples)
• Debug Addon: Zero-config debugging tool with colored logs and stats
• Performance: Event delegation in bindDom (N listeners → 1 listener)
• Repeat API: Improved create/update separation for cleaner list rendering
• Test Coverage: 193 passing tests (up from 162 in alpha.1)
• Bundle Size: ~2.1KB gzipped (temporarily slightly over budget due to new features)

📦 Key Features

1. Explicit Effect Dependencies

You can now choose between "Magic" (auto-tracking) and "Explicit" (dependency array) modes.

import { state, effect } from 'lume-js';

const store = state({ count: 0, user: 'Alice' });

// Old way: Auto-tracking (still default!)
effect(() => {
  console.log(store.count);
});

// NEW: Explicit Mode
// Only re-runs when 'count' changes, even if we read other properties!
effect(() => {
  console.log(`User ${store.user} has count: ${store.count}`);
}, [[store, 'count']]); // <--- Only tracks 'count'

2. Debug Addon 🐞

A developer-friendly tool to inspect reactive state operations.

import { createDebugPlugin, debug } from 'lume-js/addons';

const store = state({ count: 0 }, {
  plugins: [createDebugPlugin({ label: 'my-store' })]
});

debug.enable(); // Turn on logging

store.count++;
// Console: [my-store] SET count: 0 → 1

Features:

• Global Controls: debug.enable(), debug.filter('key')
• Stats API: debug.logStats() shows a table of GET/SET/NOTIFY operations
• Stack Traces: Find exactly where a state change originated

3. Event Delegation in bindDom

We've rewritten bindDom to use a single event listener on the root element instead of attaching listeners to every input.

• O(1) lookup using Map
• Huge memory savings for large forms
• Completely internal change (no API breakage)

📚 Resources

• Documentation: README.md
• Effect API: docs/api/core/effect.md
• Debug Addon: docs/api/addons/debug.md
• Changelog: CHANGELOG.md

📊 Stats & Improvements

Test Coverage

• 193 tests (up from 162)
• Added 6 new tests for Explicit Effects
• Added 24 new tests for Debug Addon
• 100% code coverage maintained

Bundle Size

• Core: 2.14 KB gzipped (slightly over 2KB budget)
• Reason: Added explicit dependency parsing and event delegation logic. Optimization planned for Beta release.

⚙️ Installation

For Early Adopters

npm install lume-js@next

⚠️ Alpha Release Notice

This is an alpha release intended for testing and feedback.
Not recommended for production until stable v2.0.0.

💬 Getting Help

• Questions: Open a GitHub Discussion
• Bugs: Open a GitHub Issue

Happy coding with Lume.js! 🌟

Full Changelog: v2.0.0-alpha.1...v2.0.0-alpha.2

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This discussion was created from the release v2.0.0-alpha.2.