Warning when trying to require a module which is not installed but not necessary

Question

I am trying to require a module in a file that would be used only if the module is actually available. So the module is totally optional. This code will be distributed as part of a 3rd party library. The issue is that any user using webpack will see their build fail if I use import, so I ended up using:

let webrtc = {};
try {
  webrtc = require('my-optional-module');
} catch (err) {}

But even with this code, they will get a warning on projects that don't need this optional module:

[WEB] WARNING in ./node_modules/xxx
[WEB] Module not found: Error: Can't resolve 'my-optional-module' in '/Users/xxx/node_modules/xxx'

Edit: Using the answer below

let webrtc = {};
if(require.resolve('my-optional-module')) {
  webrtc = require('my-optional-module');
}

But I get this warning:

Critical dependency: the request of a dependency is an expression

And this error:

Module not found: Error: Can't resolve 'my-optional-module' in xxx

Edit2:

Based on webpack instruction to do dynamic imports, I also tried:

var webrtc = {};
require.ensure(['my-optional-module'], function (require) {
  return webrtc = require('my-optional-module');
});

But I still get:

Module not found: Error: Can't resolve 'my-optional-module' in xxx

Answer 1

It seems like this is a common issue in webpack. According to the configuration docs, you can use the flag module: { exprContextCritical: false } in your webpack.config.js to suppress this warning globally across your project, though the flag is considered deprecated and you may find more highly recommended solutions in the issue I linked.