ESFive

0.1.1 verified Fri May 01 auth: no javascript deprecated

ESFive is a minimal ES5-to-ES3 transpiler, version 0.1.1, last updated in 2012. It converts ECMAScript 5 constructs (like Object.create, Array.isArray, property descriptors, strict mode) into ES3-compatible code. Release cadence is unknown and appears dormant. Key differentiator: very early attempt at ES5-to-ES3 transpilation, now obsolete due to modern transpilers like Babel.

Common errors

error Cannot find module 'esfive' ↓

cause Package not installed or missing.

fix

Run 'npm install esfive'.

error Object.defineProperty is not a function ↓

cause Output not run in an ES5 environment; requires polyfill.

fix

Use an ES5 shim or ensure ES5+ runtime.

Warnings

deprecated This package is unmaintained since 2012 and not recommended for new projects. ↓

fix Use Babel or another modern transpiler.

gotcha Does not convert all ES5 features (e.g., getters/setters, ES6). ↓

fix Check the source for supported features.

gotcha Compiled output may not fully preserve semantics of ES5 strict mode. ↓

fix Review output for correctness.

Install

npm install esfive

yarn add esfive

pnpm add esfive

Imports

default

wrong

import esfive from 'esfive';

correct

var esfive = require('esfive');

No ES6 module support; CommonJS only.

compile
wrong
```
esfive.compile() with wrong arguments
```
correct
```
var result = esfive.compile('...');
```
Main API function; accepts ES5 source string, returns object with 'code' property.

compileFile

wrong

esfive.compileFile with non-string path

correct

var result = esfive.compileFile('file.js');

Reads file and transpiles; callback not supported.

Quickstart

Transpile a simple ES5 property definition to ES3.

var esfive = require('esfive');
var input = 'Object.defineProperty(o, "p", {value: 1});';
var output = esfive.compile(input);
console.log(output.code);