Webpack 3.10.0 incompatibility

[montogeek]

Hello again!
Webpack 3.10.0 allows you to pass an array of rules using the rules or loaders key:

module: {
	loaders: [
	  {
	    test: /\.handlebars$/,
	    exclude: /(node_modules|bower_components|public\/)/,
	    use: [
	      {
	        loader: 'handlebars-loader',
	        options: { inlineRequires: 'static/icons' }
	      }
	    ]
	  },
	]
}

But this plugin only checks for the rules key, since it is undefined, it would reset the rules, deleting the user loaders configuration:

sentry-webpack-plugin/src/index.js

Lines 38 to 40 in 955615b

	if (typeof changedCompiler.options.module.rules === 'undefined') {
	changedCompiler.options.module.rules = [];
	}

I guess webpack supports this for historical reasons, I am not sure if the plugin should handle this case or the user should be more careful with its webpack configuration or webpack should no support it.

More info in the webpack migration guide: https://webpack.js.org/guides/migrating/#module-loaders-is-now-module-rules
Source code on webpack side: https://github.com/webpack/webpack/blob/f352436a0fd6491b8cc1aadeddfbe02c878686ff/lib/NormalModuleFactory.js#L49

As you can see rules is used if defined.

This bug was introduced in #20

Since it is supported by webpack I think the plugin should support it.

The solution should be adding an additional check for loaders key.

[kamilogorek]

Fix published as 1.3.3. Please let us know if it solves the issue :)

[montogeek]

It works, thank you!