A minimalist, functional JavaScript toolkit for mere mortals.
CanaryJS wraps the JavaScript you already know in a functional overcoat, then offers you a nice cup of tea.
- Includes most built-in JS methods—but curried, data-last, and pleasantly unfussy.
- Designed to be simple enough for mortals.
- Easy to learn, hard to outgrow.
- Works great on its own, or as an on-ramp to Ramda — and for deeper type-driven FP, Sanctuary.
If you’ve glanced at lodash/fp and felt it looked a bit like a supermarket sweep, CanaryJS is the corner shop: just the essentials, nicely arranged.
npm i canary-jsZero dependencies. ES Module. Tree‑shakable.
Also available via CDN:
import * as C from 'https://esm.sh/canary-js@latest'import * as C from 'canary-js'
const isEven = C.pipe(C.flip(C.modulo)(2), C.equals(0))
const add10 = C.add(10)
const transform = C.pipe(C.filter(isEven), C.map(add10))
const result = transform([1, 2, 3, 4])
console.log(result) // → [12, 14]| Principle | What it means |
|---|---|
| Curried & data‑last | Functions take arguments one at a time, with data passed last—perfect for pipe. |
| Pure & predictable | No mutation. Functions always return the same output for the same input. |
| Partial application | You can pass fewer arguments to get a new function. Build behavior gradually. |
| Built‑ins first | Array, String, Number, Object, and Boolean methods |
| Ramda‑compatible names | Familiar vocabulary if you move to Ramda. |
| Small surface | ~80 functions; your brain remains underwhelmed. |
map, filter, reduce, find, findIndex, findLast, indexOf, lastIndexOf, some, every, includes, at, flat, flatMap, slice, concat, join, reverse, sort, length
split, trim, trimStart, trimEnd, repeat, toUpper, toLower, startsWith, endsWith, padStart, padEnd
add, subtract, multiply, divide, modulo, abs, floor, round, ceil, pow
keys, values, entries, fromEntries, prop, freeze, seal, is
equals, not, negate, lt, lte, gt, gte
identity, always, converge, tap, pipe, compose, curry, uncurry, addIndex, flip, binary, trinary
ifElse, cond, tryCatch
| Feature | Where to look |
|---|---|
Placeholders (__) |
Ramda |
Fancy combinators (juxt, lens, zipWith) |
Ramda |
| Maybe, Either, and other Fantasy‑Land‑certified ADTs | SanctuaryJS |
| Lenses, traversals, profunctors (brace yourself) | Ramda & friends |
CanaryJS keeps the water shallow; when you’re ready to dive, Ramda and Sanctuary have the deep end nicely chlorinated.
Why CanaryJS?
It’s named after Canary Wharf in London, where the idea for the library clicked into place—over a coffee and a long think about functional programming.
This is a second attempt, after learning firsthand how quickly a utility library can grow too large, while still not quite measuring up to its inspirations. CanaryJS is a fresh start—intentionally small, focused, and designed to help others avoid some of the detours I took along the way.
Nothing to do with canaries in mines, alerts, or early warning systems. Probably.
MIT © 2025 Brad Mehder
