v0.2.1

Advanced Guard Features

Release Date: January 19, 2026

This release introduces powerful new guard composition utilities and enhanced debugging for complex dependency trees.

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New Features

guard.map() Composition Helper

A new way to transform sources directly into guards with full semantic tracking. This replaces the legacy compute for most use cases.

const todos = source([{ done: false }, { done: true }]);

// Reactive guard derived from source
const doneCount = guard.map(todos, (list) => list.filter((t) => t.done).length);

// doneCount works as a full Guard<number>
console.log(doneCount.state()); // { status: "ok", value: 1 }

InferGuardType<T> Type Helper

Extracting types from guards is now seamless with the new InferGuardType utility. Perfect for creating robust TypeScript interfaces.

import { guard, type InferGuardType } from "@pulse-js/core";

const authGuard = guard("auth", async () => fetchUser());
type AuthUser = InferGuardType<typeof authGuard>; // User | undefined

Enhanced Guard Debugging

The .explain() tree now includes the specific failure reasons for every sub-dependency, eliminating the guesswork in complex guard chains.

/* New explain() output for a failed guard: */
{
  "name": "can-place-order",
  "status": "fail",
  "reason": "Insufficient balance",
  "dependencies": [
    { "name": "has-items", "status": "ok" },
    {
      "name": "sufficient-balance",
      "status": "fail",
      "reason": "Balance is too low"
    }
  ]
}

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Core (@pulse-js/core v0.2.1)

• guard.map: Native implementation for source transformations
• Improved explain(): Deep dependency trees now propagate reasons

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📦 Package Versions

• @pulse-js/core: 0.2.1
• @pulse-js/tools: 0.1.9
• @pulse-js/react: 0.1.9
• @pulse-js/vue: 0.1.3
• @pulse-js/svelte: 0.1.5