babel-preset-conglomerate/modify.js

/* eslint-disable no-console, camelcase */

'use strict'

const path = require('path')
// const relative = require('require-relative')

function req (name) {
	return require(name)
}

function babelRequire (type, name) {
	let mod
	if (!name.match(/^babel-(preset|plugin)-/)) {
		try {
			mod = req('babel-' + type + '-' + name)
		}
		catch (err) {}
	}
	return mod
}


module.exports = function (presetInput, modifications) {
	modifications = modifications || {}
	const nameDrops = modifications.nameDrops !== false

	let preset

	if (typeof presetInput === 'string') {
		if (!presetInput.match(/(^babel-preset-|\/)/)) {
			try {
				preset = require.resolve('babel-preset-' + presetInput)
			}
			catch (err) {
				console.log(err)
			}
		}
		if (!preset) {
			preset = require.resolve(presetInput)
		}
	}

	const originalConfig = require(preset)
	const pathRoot = path.dirname(preset)
	const config = {}

	for (const key in originalConfig) {
		if (originalConfig.hasOwnProperty(key)) {
			config[key] = originalConfig[key]
		}
	}

	const plugins = config.plugins = (config.plugins || []).slice()

	function getPlugin (name) {
		let mod
		try {
			mod = babelRequire('plugin', name, pathRoot)
		}
		catch (err) {}

		if (!mod) {
			try {
				mod = babelRequire('plugin', name)
			}
			catch (err2) {}
		}

		return mod
	}

	function isSameName (a, b) {
		if (typeof a !== 'string' || typeof b !== 'string') return false
		return a.replace(/^babel-plugin-/i, '').toLowerCase() === b.replace(/^babel-plugin-/i, '').toLowerCase()
	}

	function indexOf (list, name) {
		const mod = getPlugin(name)
		if (!mod && process.env.NODE_ENV === 'development') {
			console.warn('no module found for: ' + name)
		}

		for (let i = 0; i < list.length; i++) {
			const p = Array.isArray(list[i]) ? list[i][0] : list[i]
			if ((mod && p === mod) || isSameName(p, name) || (p._original_name && isSameName(p._original_name, name))) {
				return i
			}
		}
		return -1
	}

	Object.keys(modifications).forEach(function (key) {
		if (key === 'nameDrops') return

		const value = modifications[key]
		const index = indexOf(plugins, key)

		if (value === false) {
			if (index < 0 && process.env.NODE_ENV === 'development') {
				console.warn(key + ' not found', __dirname)
			}

			plugins.splice(index, 1)
		}
		else {
			let p = getPlugin(key)
			if (nameDrops) {
				p._original_name = key
			}
			if (value !== true) {
				p = [p].concat(value)
			}
			if (index < 0) {
				plugins.push(p)
			}
			else {
				plugins[index] = p
			}
		}
	})

	return config
}