rollup-plugin-strict-alias

Define aliases when bundling packages with Rollup. This is like rollup-plugin-alias with strict aliases matched with === instead of startWith, like Webpack. See the Note below for details.

When we write tests, we may want an easier way to access the local library we are testing or mocking libraries. We may also define aliases to counteract "require hell" and get rid of all those ../../../ imports we may have in the process.

For Webpack users: This is a plugin to have a resolve.alias functionality in Rollup.

Installation

npm install rollup-plugin-strict-alias

Usage

import { rollup } from 'rollup';
import alias from 'rollup-plugin-strict-alias';

rollup({
  entry: './src/index.js',
  plugins: [alias({
    somelibrary: './mylocallibrary'
  })],
});

An optional resolve array with file extensions can be provided. If present local aliases beginning with ./ will be resolved to existing files:

import { rollup } from 'rollup';
import alias from 'rollup-plugin-strict-alias';

rollup({
  entry: './src/index.js',
  plugins: [alias({
    resolve: ['.jsx', '.js']
    foo: './bar',  // Will check for ./bar.jsx and ./bar.js
  })],
});

If not given local aliases will be resolved with a .js extension.

Note

This plugins is different to rollup-plugin-alias as it will check the plugin with a strict equal rather than a startWith function.

For example here is the behaviour of rollup-plugin-alias:

// with this config:
alias({
  'react': 'preact-compat'
})
// Those imports:
import {Component} from 'react';
import {Router} from 'react-router';
// will be turned into:
import {Component} from 'preact-compat';
import {Router} from 'preact-compat-router';
// because it only matches the beginning of the import name to replace it.

But this plugin works like that:

// with this config:
alias({
  'react': 'preact-compat'
})
// Those imports:
import {Component} from 'react';
import {Router} from 'react-router';
// will be turned into:
import {Component} from 'preact-compat';
import {Router} from 'react-router';
// which is more like the way Webpack aliases work

It also handles importing module subfolders:

// with this config:
alias({
  'lodash': 'lohyphen'
})
// This import:
import map from 'lodash/map';
import flow from 'lodash/fp/flow';
// will be turned into:
import map from 'lohyphen/map';
import flow from 'lohyphen/fp/flow';

Also, I'm not starting a competition, but there hasn't been any commits on rollup-plugin-alias for 5 months and I need those features.