How to check in node if module exists and if exists to load?

Question

I need to check if file/(custom)module js exists under some path. I tried like

var m = require(\'/home/test_node_project/per\');
but it throws error

Answer 1

It is possible to check if the module is present, without actually loading it:

function moduleIsAvailable (path) {
    try {
        require.resolve(path);
        return true;
    } catch (e) {
        return false;
    }
}

Documentation:

require.resolve(request[, options])

Use the internal require() machinery to look up the location of a module, but rather than loading the module, just return the resolved filename.

Note: Runtime checks like this will work for Node apps, but they won't work for bundlers like browserify, WebPack, and React Native.