Prevent Critical dependency Warnings When Bundling MongoDB with WebPack

[Lonniebiz]

I use webpack 4.25.0 to bundle mongodb 3.2.7 into a node.js 10.16.0 app. The bundle works fine, but each time I build I have to see these warnings:

WARNING in ./node_modules/require_optional/index.js 82:18-42
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mongodb-core/index.js
 @ ./node_modules/mongodb/index.js
 @ ./src/utility/mongo.mjs
 @ ./src/server.js

WARNING in ./node_modules/require_optional/index.js 90:20-44
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mongodb-core/index.js
 @ ./node_modules/mongodb/index.js
 @ ./src/utility/mongo.mjs
 @ ./src/server.js

WARNING in ./node_modules/require_optional/index.js 97:35-67
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mongodb-core/index.js
 @ ./node_modules/mongodb/index.js
 @ ./src/utility/mongo.mjs
 @ ./src/server.js

This may have something to do with the fact that I use Ecmascript Modules instead of Common.js modules to import the mongodb package; my mongo.mjs file starts like this:

import { default as mongodb } from 'mongodb';
const MongoClient = mongodb.MongoClient;

To avoid seeing these warnings on every build, I've added an object to my webpack.config.js file that looks like this:

let wp = {}; wp.stats = {}; wp.stats.warningsFilter = (warning)=>
{
	let aryModulesToBlockWarningsFrom =
	[
		"node_modules/require_optional/index.js"
	];

	let block = false;
	aryModulesToBlockWarningsFrom.forEach((modulePath)=>
	{
		if(RegExp(modulePath).test(warning) === true)
		{
			block = true;
		}
	});
	return block;
};

However, I was hoping that the require_optional developers might be able to enhance their code in a way it would still work great but just not produce these warning upon bundling mongodb.

[mbparker]

This is still a bug.

[rendall]

This is not a require_optional bug, but rather a feature of webpack. When webpack encounters a conditional dependency it doesn't know which dependency should be bundled with it, so it takes them all, and it issues a warning.

The mongodb node driver uses require_optional in at least one file, to load bson-ext or bson depending on availability, which means that webpack is warning you that it's bundling both of them

There is a fix involving the webpack plugin ContextReplacementPlugin, but I have not yet figured out / found out how to do it. netlify-lambda uses a separate webpack config. I'll come back and update when I have more info