add reset! and improve errors when no label set

.rspec

@@ -1,2 +1,2 @@
 --color
---format progress
+--format documentation

.travis.yml

@@ -1,4 +1,4 @@
-script: "bundle exec rake"
+script: "bundle exec rspec"
 rvm:
   - 1.8.7
   - 1.9.2

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    whitelabel (0.1.0)
+    whitelabel (0.2.0)
 
 GEM
   remote: https://rubygems.org/

lib/whitelabel.rb

@@ -37,7 +37,12 @@ def with_label(tmp=nil)
     end
 
     def [](accessor)
+      raise "set a label before calling '#{accessor}'" if self.label.nil?
       self.label.send :"#{accessor}"
     end
+
+    def reset!
+      Thread.current[:whitelabel] = nil
+    end
   end
 end

lib/whitelabel/version.rb

@@ -1,3 +1,3 @@
 module Whitelabel
-  VERSION = "0.1.1"
+  VERSION = "0.2.0"
 end

spec/lib/whitelabel_spec.rb

@@ -3,9 +3,11 @@
 
 describe Whitelabel do
   let(:path) { fixture_path("whitelabel.yml") }
+  let(:dummy) { Dummy.new('some_id', 'some_name') }
 
   before(:each) do
     Whitelabel.labels = []
+    Whitelabel.reset!
   end
 
   context "initialization" do
@@ -50,13 +52,27 @@
       Whitelabel.label.should eql(label)
     end
 
+    it "should throw a meaningfull error when no label is set" do
+      expect { Whitelabel[:blame] }.to raise_error("set a label before calling 'blame'")
+    end
+
     context "with current label" do
       before(:each) do
-        Whitelabel.label = Dummy.new('some_id', 'some_name')
+        Whitelabel.label = dummy
+      end
+
+      context "resetting" do
+        it "should reset the current label" do
+          Whitelabel.label.should be(dummy)
+          Whitelabel.reset!
+          Whitelabel.label.should be_nil
+        end
       end
 
-      it "should access a label property via []" do
-        Whitelabel[:name].should eql('some_name')
+      context "accessing values" do
+        it "should access a label property via []" do
+          Whitelabel[:name].should eql('some_name')
+        end
       end
     end
   end