# ruanyf/es-checker

A feature detection library for ECMAScript in node.js and browser.

Repository: https://github.com/ruanyf/es-checker
Canonical: https://ross.abutalabs.com/products/es-checker
Homepage: http://ruanyf.github.io/es-checker
Language: JavaScript
License Family: other
Last push: 2019-07-16T13:38:38+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4083, "days_push": 2605, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1019, forks 151 (observed 2026-08-28T04:03:15.180922+00:00)

## What it is
A feature detection library that checks how much of ECMAScript 6 (ES2015) a JavaScript runtime supports, usable from the command line, Node.js, or the browser. It exposes boolean flags for individual ES6 features like let/const, arrow functions, generators, and classes.

## Use cases
- check which ES6 features my browser supports
- detect if node supports let and const before using them
- run es-checker from the command line to see ES6 support
- feature-test arrow functions and generators at runtime
- show a demo page of ECMAScript 2015 support

## When to choose
- you need runtime ES6 feature detection in legacy environments or old browsers
- you want a quick CLI report of a JavaScript engine's ES6 support

## When to avoid
- you target modern runtimes where ES6 is universally supported
- you need up-to-date detection of newer ECMAScript versions (ES2017+)
- you need an actively maintained dependency

## Facets
- artifact type: library
- maturity: abandoned
- function: developer-tools, cli
- domain: developer-tools, programming-languages, web-development
- platform: browser, cli, cross-platform
- tags: ecmascript, es6, feature-detection, javascript, nodejs

## Member repositories
- ruanyf/es-checker (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:15.180922+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:09:24.711313+00:00, confidence not recorded.
  - readme: https://github.com/ruanyf/es-checker (fetched 2026-08-28T04:03:15.180922+00:00, sha 619f45d3a33b)
  - homepage: http://ruanyf.github.io/es-checker (fetched 2026-08-29T13:09:44.981988+00:00, sha 179ed96b1437)
  - registry_npm: https://registry.npmjs.org/es-checker (fetched 2026-08-29T13:09:44.992118+00:00, sha adba4a574e50)
- Data as of 2026-08-30T08:39:29.467469+00:00.