babel-plugin-module-resolver

A Babel plugin to add a new resolver for your modules when compiling your code using Babel. This plugin allows you to add new "root" directories that contain your modules. It also allows you to setup a custom alias for directories, specific files, or even other npm modules.

Description

This plugin can simplify the require/import paths in your project. For example, instead of using complex relative paths like ../../../../utils/my-utils, you can write utils/my-utils. It will allow you to work faster since you won't need to calculate how many levels of directory you have to go up before accessing the file.

// Use this:
import MyUtilFn from 'utils/MyUtilFn';
// Instead of that:
import MyUtilFn from '../../../../utils/MyUtilFn';

// And it also work with require calls
// Use this:
const MyUtilFn = require('utils/MyUtilFn');
// Instead of that:
const MyUtilFn = require('../../../../utils/MyUtilFn');

Usage

If you're coming from babel-plugin-module-alias, please read this section: Updating from babel-plugin-module-alias.

Install the plugin

$ npm install --save-dev babel-plugin-module-resolver

Specify the plugin in your .babelrc with the custom root or alias. Here's an example:

{
  "plugins": [
    ["module-resolver", {
      "root": ["./src"],
      "alias": {
        "test": "./test",
        "underscore": "lodash"
      }
    }]
  ]
}

Options

• root: Array of root directories. Specify the paths or a glob path (eg. ./src/**/components)
• alias: Map of alias. You can also alias node_modules dependencies, not just local files.
• extensions: Array of extensions used in the resolver. Override the default extensions (['.js', '.jsx', '.es', '.es6']).
• cwd: By default, the working directory is the one used for the resolver, but you can override it for your project.
  • The custom value babelrc will make the plugin look for the closest babelrc configuration based on the file to parse.

Regular expression alias

It is possible to specify an alias using a regular expression. To do that, either start an alias with '^' or end it with '$':

{
  "plugins": [
    ["module-resolver", {
      "alias": {
        "^@namespace/foo-(.+)": "packages/\\1"
      }
    }]
  ]
}

Using the config from this example '@namespace/foo-bar' will become 'packages/bar'.

You can reference the n-th matched group with '\\n' ('\\0' refers to the whole matched path).

To use the backslash character (\) just escape it like so: '\\\\' (double escape is needed because of JSON already using \ for escaping).

Updating from babel-plugin-module-alias

babel-plugin-module-resolver is a new version of the old babel-plugin-module-alias. Therefore, you also need to make a few modifications to your plugin configuration to make it work with this new plugin.

Updating is very easy. For example, if you had this configuration:

// This configuration is outdated, this is just an example
{
  "plugins": [
    ["module-alias", [
      { "src": "./src/utils", "expose": "utils" },
      { "src": "./src/components", "expose": "components" },
      { "src": "./src/actions", "expose": "actions" },
      { "src": "npm:lodash", "expose": "underscore" }
    ]]
  ]
}

You only have to update the plugin options to be like this:

{
  "plugins": [
      ["module-resolver", {
        "root": ["./src"],
        "alias": {
          "underscore": "lodash"
        }
      }]
    ]
}

ESLint plugin

If you're using ESLint, you should use eslint-plugin-import, and eslint-import-resolver-babel-module to remove falsy unresolved modules.

Usage with Flow

To allow Flow to find your modules, add configuration options to .flowconfig.

For example, a React component is located at src/components/Component.js

// Before
import '../../src/components/Component';

// After - Flow cannot find this now
import 'components/Component';

Instruct Flow where to resolve modules from:

# .flowconfig

[options]
module.system.node.resolve_dirname=node_modules
module.system.node.resolve_dirname=src

Be sure to add any sub-directories if you refer to files further down the directory tree:

// Located at src/store/actions
import 'actions/User'

module.system.node.resolve_dirname=src/store

More configuration options are located in the Flow documentation

Editors autocompletion

• Atom: Uses atom-autocomplete-modules and enable the babel-plugin-module-resolver option.
• IntelliJ/WebStorm: You can add custom resources root directories, make sure it matches what you have in this plugin.

License

MIT, see LICENSE.md for details.