Separate logic into other functions for readability

plugins/providers/virtualbox/action/network_fix_ipv6.rb

@@ -3,6 +3,7 @@ require "socket"
 
 require "log4r"
 
+require "vagrant/util/presence"
 require "vagrant/util/scoped_hash_override"
 
 module VagrantPlugins
@@ -12,6 +13,7 @@ module VagrantPlugins
       # a VM with an IPv6 host-only network will someties lose the
       # route to that machine.
       class NetworkFixIPv6
+        include Vagrant::Util::Presence
         include Vagrant::Util::ScopedHashOverride
 
         def initialize(app, env)
@@ -41,17 +43,15 @@ module VagrantPlugins
           # If we have no IPv6, forget it
           return if !has_v6
 
-          ifaces = env[:machine].provider.driver.read_network_interfaces
-          ifaces.select! { |id, iface| iface[:type] == :hostonly }
-          iface_names = ifaces.values.map { |iface| iface[:hostonly] }
-          networks = env[:machine].provider.driver.read_host_only_interfaces
-          networks.select! { |network| iface_names.include?(network[:name]) }
-          networks.each do |network|
-            next if network[:ipv6] == ""
-            next if network[:status] != 'Up'
-            ip = IPAddr.new(network[:ipv6]) |
-              ('1' * (128 - network[:ipv6_prefix].to_i)).to_i(2)
+          networks(env).each do |network|
+            next if !present?(network[:ipv6])
+            next if network[:status] != "Up"
+
+            ip = IPAddr.new(network[:ipv6])
+            ip |= ("1" * (128 - network[:ipv6_prefix].to_i)).to_i(2)
+
             @logger.info("testing IPv6: #{ip}")
+
             begin
               UDPSocket.new(Socket::AF_INET6).connect(ip.to_s, 80)
             rescue Errno::EHOSTUNREACH
@@ -60,6 +60,21 @@ module VagrantPlugins
             end
           end
         end
+
+        # The list of interface names for host-only adapters.
+        # @return [Array<String>]
+        def host_only_interface_names(env)
+          env[:machine].provider.driver.read_network_interfaces
+            .map { |_, i| i[:hostonly] if i[:type] == :hostonly }.compact
+        end
+
+        # The list of networks that are tied to a host-only adapter.
+        # @return [Array]
+        def networks(env)
+          iface_names = self.host_only_interface_names(env)
+          env[:machine].provider.driver.read_host_only_interfaces
+            .select { |network| iface_names.include?(network[:name]) }
+        end
       end
     end
   end