transform-loader

0.2.4 verified Sat Apr 25 auth: no javascript maintenance

Webpack loader that allows using browserify transforms in webpack builds. Version 0.2.4 is the latest stable release (last updated 2017). It enables reuse of existing browserify transform modules (like brfs, coffeeify) within webpack's loader pipeline. Key differentiator: bridges browserify ecosystem transforms to webpack without manual porting. Supports webpack 1.x and 2.x but is not actively maintained.

Common errors

error Module not found: Error: Can't resolve 'transform-loader/cacheable' ↓

cause Incorrect subpath import or missing npm install

fix

Ensure 'transform-loader' is installed: npm install transform-loader --save-dev

error Error: DeprecationWarning: loaderUtils.getOptions is deprecated ↓

cause Using transform-loader with webpack 4+ which deprecates old loader utilities

fix

Upgrade to webpack 5 and consider using alternatives like 'brfs' loader directly

error TypeError: this.getOptions is not a function ↓

cause transform-loader not compatible with webpack 5's loader API

fix

Use webpack 4 or migrate to a maintained loader like 'brfs-loader'

Warnings

deprecated transform-loader uses deprecated loader API in webpack 2+ ↓

fix For webpack 2+, use 'enforce: post' in rule or migrate to webpack-native loaders.

gotcha Cacheable variant must be imported as subpath '/cacheable' not as query parameter ↓

fix Use 'transform-loader/cacheable?brfs' instead of 'transform-loader?brfs&cacheable'.

breaking Webpack 5 removed LoaderOptionsPlugin, breaking configs using plugin transform index ↓

fix Define transforms directly in rule options: { loader: 'transform-loader', options: { transforms: [...] } } or avoid using plugin-based transforms.

gotcha Applied to all files in default config, causing performance degradation in watch mode ↓

fix Use 'transform-loader/cacheable' variant or narrow test pattern to specific files.

deprecated Project last updated in 2017; no webpack 5 support ↓

fix Consider using alternative loaders like brfs directly or migrate to webpack-native solutions.

Install

npm install transform-loader

yarn add transform-loader

pnpm add transform-loader

Imports

default import
wrong
```
const transformLoader = require('transform-loader')
```
correct
```
import transformLoader from 'transform-loader'
```
Loader is typically used in webpack config as string reference, not directly imported in code.
cacheable variant
wrong
```
import 'transform-loader?cacheable'
```
correct
```
import 'transform-loader/cacheable'
```
Use the subpath '/cacheable' to enable caching, not a query parameter.
Webpack config usage
```
module.exports = { module: { rules: [{ test: /\.js$/, loader: 'transform-loader?brfs' }] } }
```
Loader is configured via webpack config with query string; no direct import needed.

Quickstart

Configures webpack to use the brfs browserify transform via transform-loader on all JavaScript files.

// webpack.config.js
module.exports = {
  context: __dirname,
  entry: './index.js',
  module: {
    loaders: [
      {
        test: /\.js$/,
        loader: 'transform-loader?brfs'
      }
    ]
  }
};