readmongo/node_modules/enhanced-resolve/lib/ConcordMainPlugin.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
"use strict";

const path = require("path");
const concord = require("./concord");
const DescriptionFileUtils = require("./DescriptionFileUtils");

module.exports = class ConcordMainPlugin {
	constructor(source, options, target) {
		this.source = source;
		this.options = options;
		this.target = target;
	}

	apply(resolver) {
		const target = resolver.ensureHook(this.target);
		resolver
			.getHook(this.source)
			.tapAsync("ConcordMainPlugin", (request, resolveContext, callback) => {
				if (request.path !== request.descriptionFileRoot) return callback();
				const concordField = DescriptionFileUtils.getField(
					request.descriptionFileData,
					"concord"
				);
				if (!concordField) return callback();
				const mainModule = concord.getMain(request.context, concordField);
				if (!mainModule) return callback();
				const obj = Object.assign({}, request, {
					request: mainModule
				});
				const filename = path.basename(request.descriptionFilePath);
				return resolver.doResolve(
					target,
					obj,
					"use " + mainModule + " from " + filename,
					resolveContext,
					callback
				);
			});
	}
};