fly-babel

2.1.1 verified Sat Apr 25 auth: no javascript maintenance

Babel plugin for the Fly build system, version 2.1.1. It allows you to transpile ES6/ES2015+ code using Babel within Fly pipelines. The plugin supports standard Babel options (presets, plugins, sourceMaps, etc.) and a preload feature that automatically loads Babel plugins/presets from package.json. Release cadence is low; last release was in 2018. Key differentiator: tight integration with Fly, including preloading and simple generator-based task syntax. Requires Node >= 4.6 and Fly 2.0+.

Common errors

error TypeError: fly.source(...).babel is not a function ↓

cause fly-babel plugin not installed or not registered with Fly.

fix

Run npm install --save-dev fly-babel and ensure Fly is configured to load the plugin (e.g., via 'fly clear' or plugin registration).

error Error: Couldn't find preset 'es2015' relative to directory ↓

cause Required Babel preset not installed.

fix

Install the preset: npm install --save-dev @babel/preset-env (or babel-preset-es2015 for older Babel).

error ReferenceError: regeneratorRuntime is not defined ↓

cause Using ES6 generators (async/await) without proper Babel runtime polyfill.

fix

Install and configure 'babel-plugin-transform-runtime' or include 'babel-polyfill' in your code.

Warnings

breaking Version 2.1.0 dropped Node 4.x support; requires Node >= 6.x. ↓

fix Upgrade Node to >=6.x, or use fly-babel@0.2.1 for Node 4.x support.

deprecated This plugin is for the legacy Fly build system (flyjs). Fly is no longer maintained. ↓

fix Consider migrating to modern build tools like Webpack, Rollup, or esbuild.

gotcha The .babel() method must be called inside a generator function (function *). Using async/await or regular functions will fail. ↓

fix Use 'function * (fly) { ... }' syntax. Promises are not supported.

gotcha preload: true only works if babel plugins/presets are listed in package.json under 'devDependencies' or 'dependencies' and named conventionally (e.g., 'babel-preset-*' or 'babel-plugin-*'). ↓

fix Ensure packages are installed and named properly. For custom names, configure presets/plugins manually.

gotcha Source maps may not work correctly if the source is processed by multiple plugins (e.g., fly-clear or fly-concat). ↓

fix Test source map output; consider using 'inline' or 'both' for simpler debugging.

Install

npm install fly-babel

yarn add fly-babel

pnpm add fly-babel

Imports

fly-babel plugin
wrong
```
import flyBabel from 'fly-babel';
```
correct
```
const flyBabel = require('fly-babel'); // used internally by Fly, no direct import in user code
```
Plugin is mounted via Fly's system; user does not import directly. Instead, configure in .fly.js or flyfile.js.

.babel()

wrong

fly.source('src/**/*.js').babel().target();

correct

yield fly.source('src/**/*.js').babel({ presets: ['es2015'] }).target('dist/');

Method is chained on Fly's source/target stream. Must be inside a generator function (function *).

options.preload

wrong

yield fly.source('src/**/*.js').babel({ preload: false });

correct

yield fly.source('src/**/*.js').babel({ preload: true }).target('dist/');

preload: true automatically loads Babel plugins/presets from package.json. Default false.

Quickstart

Shows basic usage of fly-babel with Babel presets and source maps in a Fly task.

// In your flyfile.js
const fly = require('fly');

export default function* (fly) {
  yield fly.source('src/**/*.js')
    .babel({
      presets: ['@babel/preset-env'],
      sourceMaps: 'inline'
    })
    .target('dist/');
}