babel-plugin-lodash-modularize

Babel plugin that replaces lodash library import statement to individual module imports.

Using individual module imports excludes the unused lodash code from the final bundle when using module bundlers such as webpack or Browserify.

Chaining

Note that use of chaining defeats most of the benefits of this plugin. There is no way to modularly import chaining dependencies. As a result, use of chaining will import all of the lodash modules that can work with chaining.

Example

Converts:

import _ from 'lodash';

_.map();

To:

import map from 'lodash/collection/map';

map();

Usage

Add to .babelrc:

{
    "plugins": [
        [
            "lodash-modularize",
            {
                "lodashVersion": "4.0.0"
            }
        ]
    ]
}

lodashVersion option defines the version of the lodash that you are using. It is used to resolve the correct path of the individual modules.

Difference from babel-plugin-lodash

babel-plugin-lodash attempts to resolve lodash module associated with the target script. The assumptions that babel-plugin-lodash makes about the node_modules path depend on the NPM version and the execution context. babel-plugin-lodash-modularize is using a hard-coded map to construct the module import path (see discussion).

babel-plugin-lodash supports lodash-fp (babel-plugin-lodash-modularize does not).

babel-plugin-lodash-modularize can be used against a code base that does not use lodash at all, i.e. babel-plugin-lodash-modularize can become part of a greater Babel preset.

In contrast to babel-plugin-lodash, babel-plugin-lodash-modularize does not restrict use of chaining. Beware of the side effects.

Development

Use npm run module-map to generate a new module map. The new module map is generated against the lodash version installed as a dependency of the babel-plugin-lodash-modularize plugin.

This approach will need to change when a new version of lodash comes out that does no longer use the same directory structure. lodashVersion plugin option is used as a form of defensive design to ensure that when such change happens we do not introduce a backwards incompatible change.