ifdef-loader

ifdef-loader

Webpack package loader that allows JavaScript/TypeScript conditional compilation (#if ... #endif).

Installation

In webpack build directory:

npm install ifdef-loader --save-dev

Configuration

Example of use with TypeScript files, enabling the DEBUG and version variables:

In webpack.config.json:

//...
{ test: /\.tsx?$/, exclude: /node_modules/, loaders: [ "ts-loader", 'ifdef-loader?DEBUG=true&version=3' ] }
//...

in example.ts:

// #if DEBUG
/* code to be included if DEBUG is defined */
//   #if version <2
/* code to be included if DEBUG is defined and version < 2*/
//   #endif
// #endif

Add ifdef-verbose to query string if you want the loader to print informations when directives are processed:

//...
{ test: /\.tsx?$/, exclude: /node_modules/, loaders: [ "ts-loader", 'ifdef-loader?ifdef-verbose=true' ] }
//...

Directives

Directives must be placed after a // doubleslash comment.

// #if SOMECOND
//   #if SOMEOTHER
/* code */
//   #endif
// #endif

At the moment the only directive supported is #if/#endif (more to come).

// #if SOMECOND
/* code to be included if SOMECOND is true */
// #endif

License

MIT