refactor: clearer export

tools/webpack-progress-reporter.js

@@ -1,8 +1,10 @@
 const ProgressPlugin = require('webpack/lib/ProgressPlugin');
 
-module.exports = (observer) =>
+const reporter = (observer) =>
 	new ProgressPlugin((progress, msg, ...details) => {
 		const [a, b] = details;
 		const state = a && b ? `[${a}, ${b}]` : '';
 		return observer.next(`${Math.round(progress * 100)}% ${msg} ${state}`);
 	});
+
+module.exports = reporter;