Always return an error in a cb

bin/config.js

@@ -7,10 +7,7 @@ require('update-notifier')({pkg: pkg}).notify()
 
 var Configstore = require('configstore')
 var configName = 'update-notifier-' + pkg.name
-
-var config = new Configstore(configName, {
-  nodeVersions: []
-})
+var config = new Configstore(configName, { nodeVersions: [] })
 
 var lastFetchCheck = config.get('lastFetchCheck')
 var now = Date.now()
@@ -20,16 +17,16 @@ var isCacheValid = now - lastFetchCheck < fetchCheckInterval
 var nodeVersions = config.get('nodeVersions')
 var hasVersions = nodeVersions.length
 
+var fetch = require('./fetch')
+
 function loadConfig (cb) {
-  if (hasVersions && isCacheValid) return cb(nodeVersions)
-  require('./fetch')(function (err, nodeVersions) {
-    if (err) {
-      if (hasVersions) return cb(nodeVersions)
-      throw err
-    }
+  if (hasVersions && isCacheValid) return cb(null, nodeVersions)
+
+  fetch(function (err, nodeVersions) {
+    if (err) return cb(hasVersions ? null : err, nodeVersions)
     config.set('nodeVersions', nodeVersions)
     config.set('lastFetchCheck', Date.now())
-    return cb(nodeVersions)
+    return cb(null, nodeVersions)
   })
 }