interpret

interpret

A dictionary of file extensions and associated module loaders.

What is it

This is used by Liftoff to automatically require dependencies for configuration files, and by rechoir for registering module loaders.

API

extensions

Map file types to modules which provide a require.extensions loader.

{
  '.babel.js': 'babel/register',
  '.cirru': 'cirru-script/lib/register',
  '.cjsx': 'node-cjsx/register',
  '.co': 'coco',
  '.coffee': 'coffee-script/register',
  '.coffee.md': 'coffee-script/register',
  '.csv': 'require-csv',
  '.iced': 'iced-coffee-script/register',
  '.iced.md': 'iced-coffee-script/register',
  '.ini': 'require-ini',
  '.js': null,
  '.json': null,
  '.json5': 'json5/lib/require',
  '.jsx': 'node-jsx',
  '.litcoffee': 'coffee-script/register',
  '.liticed': 'iced-coffee-script/register',
  '.ls': 'LiveScript',
  '.toml': 'toml-require',
  '.ts': 'typescript-register',
  '.wisp': 'wisp/engine/node',
  '.xml': 'require-xml',
  '.yaml': 'require-yaml',
  '.yml': 'require-yaml'
}

legacy

Check here to see if a legacy module should be loaded upon failure to load the main module. If a legacy module is available it is recommended to use try/catch around the requires to avoid crashing the process upon failure to load the main module.

{
  '.coffee': 'coffee-script' // old versions of coffee-script didn't have the `register` module
}

register

Check here to see if setup is needed for the module register itself with require.extensions. If a method is returned, call it with the module.

{
  'toml-require': function (module) {
    module.install();
  }
}

configurations

These configuration options should be passed into any register function with the same key.

// configurations
{
  'node-jsx': {
    extension: '.jsx',
    harmony: true
  }
}
// register
{
  'node-jsx': function (module, config) {
    module.install(config);
  }
}

jsVariants

Extensions which are javascript variants.

{
  '.js': null,
  '.babel.js': 'babel/register',
  '.cirru': 'cirru-script/lib/register',
  '.cjsx': 'node-cjsx/register',
  '.co': 'coco',
  '.coffee': 'coffee-script/register',
  '.coffee.md': 'coffee-script/register',
  '.iced': 'iced-coffee-script/register',
  '.iced.md': 'iced-coffee-script/register',
  '.jsx': 'node-jsx',
  '.litcoffee': 'coffee-script/register',
  '.liticed': 'iced-coffee-script/register',
  '.ls': 'LiveScript',
  '.ts': 'typescript-register',
  '.wisp': 'wisp/engine/node'
}

Example Usage

const interpret = require('interpret');
const path = require('path');
const resolve = require('resolve');

// register support for a defined extension
function register(filepath, cwd) {
  // find the extension of the requested filename
  var ext = path.extname(filepath);
  // see if this extension is already supported
  if (Object.keys(require.extensions).indexOf(ext) !== -1) {
    return;
  }
  // if no cwd is specified, assume we want to use the
  // directory the requested file exists in
  if (!cwd) {
    cwd = path.dirname(path.resolve(filepath));
  }
  // find out which module is needed to read this extension
  var moduleName = interpret.extensions[ext];
  // if a module exists for this extension, make it usable
  if (moduleName) {
    // find the module relative to cwd that can add support for this extension
    // optionally deal with legacy modules here
    var module = resolve.sync(moduleName, {basedir: cwd});
    // require it
    var compiler = require(module);
    // see if there is a method needed beyond requiring to enable support
    var register = interpret.register[moduleName];
    var config = interpret.configurations[moduleName];
    // if there is, run it
    if (register) {
      register(compiler, config);
    }
  }
}

Note: this is more or less exactly how rechoir works.