Tree-shaking & imports

@rtorcato/js-common is built to vanish from your bundle when you don't use it. Every module ships as its own subpath, the root entry point is empty by design, and the package is marked "sideEffects": false. Any modern bundler (esbuild, Rollup, Vite, Webpack 5+, Next.js, Astro, SvelteKit) will tree-shake unused exports automatically — but only if you import from the right place.

Always import from a subpath

✅ Good — subpath import:

import { slugify } from '@rtorcato/js-common/strings'
import { formatDate } from '@rtorcato/js-common/date'
import { chunk } from '@rtorcato/js-common/arrays'

❌ Won't work — root import:

// dist/index.js is intentionally empty. This import resolves to nothing.
import { slugify } from '@rtorcato/js-common'

The root entry point is empty on purpose. There is no barrel re-export at the top level, because barrel files defeat tree-shaking in some bundler configurations and force every consumer to pull in metadata for every module. Subpaths give the bundler one clear answer: "load this file, nothing else."

What "subpath" means

The list of subpaths is defined in package.json#exports. Each one points at a single module's dist/<name>/index.js. For example:

{
  "exports": {
    "./strings": {
      "import": "./dist/strings/index.js",
      "types": "./dist/strings/index.d.ts"
    },
    "./date": {
      "import": "./dist/date/index.js",
      "types": "./dist/date/index.d.ts"
    }
  }
}

If your editor autocompletes @rtorcato/js-common/..., it will list every available subpath. The full list is also browsable in the Modules section of this site.

Bundle size in practice

Every module's compiled JavaScript is in the 130 B – 2.5 KB range (uncompressed). Real numbers from the published 2.x build:

Module	Compiled size
try	129 B
math	150 B
json	360 B
arrays	697 B
numbers	785 B
colors	1.1 KB
datetime	1.5 KB
currency	2.3 KB
strings	2.5 KB

Gzipped these are roughly a third of that. After tree-shaking, your bundle only ships the functions you actually reference — so importing one helper from strings does not pay the full 2.5 KB cost.

Verifying it tree-shook

Check with your bundler's analyzer:

• Vite / Rollup: vite build --mode production then open stats.html via rollup-plugin-visualizer.
• webpack: webpack-bundle-analyzer.
• esbuild: --analyze flag prints a tree of bytes per module.
• Next.js: ANALYZE=true next build with @next/bundle-analyzer.

If you see @rtorcato/js-common appearing larger than the single subpath you imported, double-check that:

1. You imported from a subpath, not the root.
2. The bundler is in production mode (dev mode often skips tree-shaking).
3. You are not re-exporting everything from a local barrel file in your own codebase — barrels in your code can also defeat tree-shaking even when the library itself is shake-friendly.

Types-only subpath

@rtorcato/js-common/types is a special subpath that ships only .d.ts declarations — no runtime code. Use it to share type definitions across files without paying any bundle cost.

import type { JsonValue, UnknownRecord } from '@rtorcato/js-common/types'

Because there is no import field on the ./types export, runtime imports from this subpath will fail at resolve time — which is the intended behavior.