added test for erroneous vlan configuration

lib/puppet/provider/network_config/interfaces.rb

@@ -294,8 +294,8 @@ def self.format_file(filename, providers)
             stanza << "vlan-raw-device #{provider.options["vlan-raw-device"]}"
           else
             vlan_range_regex = %r[\d{1,3}|40[0-9][0-5]]
-            if ! provider.name.match(%r[\A([a-z]+\d+)(?::\d+|\.#{vlan_range_regex})\Z])
-              raise Puppet::Error, "Interface #{provider.name}: missing vlan-raw-device or wrong VLAN ID in the iface name "
+            if ! provider.name.match(%r[\A([a-z]+\d+)(?::\d+|\.#{vlan_range_regex})\Z])          
+              raise Puppet::Error, "Interface #{provider.name}: missing vlan-raw-device or wrong VLAN ID in the iface name"
             end
           end                 
       end      

spec/unit/provider/network_config/interfaces_spec.rb

@@ -193,6 +193,22 @@ def fixture_data(file)
       )
     end
 
+    let(:vlan10_provider) do
+      stub('vlan10_provider',
+        :name            => "vlan10",
+        :ensure          => :present,
+        :onboot          => true,
+        :hotplug         => true,
+        :family          => "inet",
+        :method          => "dhcp",
+        :ipaddress       => nil,
+        :netmask         => nil,
+        :mtu             => nil,
+        :mode            => :vlan,
+        :options         => {}        
+      )
+    end
+
     let(:eth1_4500_provider) do
       stub('eth1_4500_provider',
         :name            => "eth1.4500",
@@ -341,6 +357,13 @@ def fixture_data(file)
       end
     end
 
+    describe "writing wrong vlanNN iface blocks" do
+      let(:content) { described_class.format_file('', [vlan10_provider]) }
+      it "should fail with missing vlan-raw-device" do
+        expect { content }.to raise_error(Puppet::Error, /Interface vlan10: missing vlan-raw-device or wrong VLAN ID in the iface name/)
+      end
+    end
+
     describe "writing the options section" do
       let(:content) { described_class.format_file('', [eth1_provider]) }