Handle undefined assets when combining. (vercel#1569)

arunoda · timneutkens · commit bd80b78f5d2d · 2017-03-30T16:35:53.000+02:00
It's possible for common.js to be empty in certain cases.
So, we need to handle it.
diff --git a/server/build/plugins/combine-assets-plugin.js b/server/build/plugins/combine-assets-plugin.js
@@ -11,7 +11,10 @@ export default class CombineAssetsPlugin {
     compiler.plugin('after-compile', (compilation, callback) => {
       let newSource = ''
       this.input.forEach((name) => {
-        newSource += `${compilation.assets[name].source()}\n`
+        const asset = compilation.assets[name]
+        if (!asset) return
+
+        newSource += `${asset.source()}\n`
         delete compilation.assets[name]
       })
 
