what is require.resolve in webpack loader test

Question

I am learning this imports-loader on webpack. I've already built several webpack demo projects by following tutorials.

Here is the code to configure imports-loader:

// ./webpack.config.js

module.exports = {
    ...
    module: {
        loaders: [
            {
                test: require.resolve("some-module"),
                loader: "imports?this=>window"
            }
        ]
};

My questions:

1. Normally, the "test" should be a regex expression. What is the require.resolve("some-module") here? what does it mean?

Answer 1

require.resolve("<moduleName>") returns string which contains path to the module, for example

> require.resolve('angular')
/tmp/node_modules/angular/index.js

so in your example property test will contain string with path to the module some-module, by default webpack converts string to the regular expression so final version of loader config will be something like this:

{
  test: /^node_modules\/some-module\/index.js/,
  loader: 'imports?this=>window"
}

as you can see this loader will be applied only for one file