geowarin / babel-plugin-import-glob

Babel plugin to enable importing modules using a glob pattern

babel-plugin-import-glob

Babel plugin to enable importing modules using a glob pattern. Tested with Node.js 0.10 and above.

Installation

npm install --save-dev babel-plugin-import-glob

Then add import-glob to your .babelrc file, like:

{
  "plugins": ["import-glob"]
}

Usage

This plugin is useful if you have multiple modules but you don't want to import them one at a time.

Maybe you're using the handlebars-inline-precompile plugin and are putting your modules in a templates directory. Or you need to dynamically reference one out of several classes and don't want to maintain the lookup by hand. Perhaps you need to load multiple modules for their side-effects and wish to simply add them to a directory without additional work. If so, this plugin is for you!

Of course in the vast majority of cases you should just use normal import statements. Don't go overboard using this plugin.

You can import the default members of any matching module. Let's say you have a directory layout like this:

• index.js
• templates/main.handlebars.js
• templates/_partial.handlebars.js

In index.js you can write:

import { main, _partial } from 'glob:templates/*.handlebars.js'

You can alias members:

import { main, _partial as partial } from 'glob:templates/*.handlebars.js'

Or import all matches into a namespace object:

import * as templates from 'glob:templates/*.handlebars.js'
// Provides `templates.main` and `templates._partial`

Note that you cannot import the default from the glob pattern. The following won't work and throws a SyntaxError:

import myTemplates from 'glob:templates/*.handlebars.js' // This will throw a SyntaxError

You can load modules for their side-effects though:

import 'glob:modules-with-side-effects/*.js'

Glob patterns

The plugin uses the glob package. Please refer to its documentation regarding the pattern syntax.

The glob pattern must be relative. It may start with ./ or ../. If you don't specify either then ./ is assumed. A SyntaxError is thrown if you start the pattern with /.

The pattern is resolved relative to the file containing the import statement.

Import members

Identifiers are generated for all matches. Any common path prefix is removed, as is any common (compound) extension. File-separators in the resulting strings are replaced by dollar signs. The directory components are then converted into identifiers.

A valid identifier cannot always be generated. If that's the case a SyntaxError is thrown with more details. Similarly multiple matches may result in the same identifier. This also results in a SyntaxError being thrown.

For the templates example above the matches are:

• templates/main.handlebars.js
• templates/_partial.handlebars.js

Both matches share templates/ as their path prefix, and .handlebars.js as their extension. These strings are removed, resulting in main and _partial. These are valid identifiers and therefore used as the import members.

A SyntaxError is throw when importing a member that does not correspond to a match:

import { doesNotExist } from 'glob:templates/*.handlebars.js' // This will throw a SyntaxError

Here's an overview of how the members are determined for additional matches. Assume templates/ is the common path prefix and .handlebars.js the common extension:

Match	Result	Reason
templates/terms-and-conditions.handlebars.js	termsAndConditions	The - cannot be used in the identifier so it's removed. The following character is uppercased
templates/blog/footer.handlebars.js	blog$footer	The blog directory wasn't removed so is joined with the footer name using a dollar sign
templates/-main.handlebars.js	SyntaxError	The - is removed, resulting in the same identifier as for main.handlebars.js
templates/new.handlebars.js	_new	new is a reserved word so it's prefixed with an underscore
templates/blog/new.handlebars.js	blog$new	Even though new is a reserved word, it's combined with blog$ so no prefix is necessary
templates/404.handlebars.js	_404	Identifiers can't start with digits so it's prefixed with an underscore
templates/error-pages/404.handlebars.js	errorPages$404	Now that 404 is combined with errorPages$ it no longer needs to be prefixed
templates/🙊.handlebars.js	SyntaxError	No identifier can be generated for 🙊