babel-plugin-rewrite-require

Babel plugin for rewriting requires/imports

Module aliases

This plugin allows rewriting ES6 module imports and CommonJS-style require() calls using a simple module alias map:

{
  "aliases": {
    "some-module": "some-replacement-module",
    "another-module": "another-module/browser"
  },
}

Non-string literals

With the following option enabled, require() calls that do not have a simple string literal argument will be replaced with an exception being thrown:

{
  "throwForNonStringLiteral": true
}

This approach is used by several browserify modules to detect whether their built-in counterparts are available (e.g. require('cry'+'pto')) and should be enabled if you use this Babel plugin to alias node built-in modules to browserify modules.

Optional modules

A common pattern found in node modules is to check whether a certain dependency is available:

try {
  require('some-optional-dependency');
} catch (ex) {
  // Ignore, or load polyfill, or ...
}

Because React Native's packager resolves require() calls during dependency resolution, it will require 'some-optional-dependency' to be present and resolvable. If this module will never be available to your React Native app, and you want the runtime exception occur so that the catch clause can do its thing, you can blacklist these dependencies from ever being resolved. Instead, those require() calls will be replaced with an exception being thrown:

{
  "throwForModules": [
    "some-optional-dependency"
  ]
}

Optional files

If the file that an import or require() call would resolve to is missing, it's usually up to node or the packager (e.g. webpack) to deal with that -- potentially creating the bundle would fail at build time rather than incurring an exception at runtime (which is what happens in node). To replace the import of an non-existent file or module with a runtime exception, use the following option:

{
  "throwForMissingFiles": [
    "/path/to/some/optional/configuration.json",
    "/path/to/build.artifact"
  ]
}