Add started? method to adapters

lib/listen/adapter.rb

@@ -83,6 +83,14 @@ def stop
       @turnstile.signal # ensure no thread is blocked
     end
 
+    # Returns whether the adapter is statred or not
+    #
+    # @return [Boolean] whether the adapter is started or not
+    #
+    def started?
+      @stop.nil? ? false : !@stop
+    end
+
     # Blocks the main thread until the poll thread
     # calls the callback.
     #

spec/support/adapter_helper.rb

@@ -43,6 +43,31 @@ def watch(listener, *paths)
       end
     end
   end
+
+  describe '#started?' do
+    context 'with a new adapter' do
+      it 'returns false' do
+        subject.should_not be_started
+      end
+    end
+
+    context 'with a stopped adapter' do
+      before { subject.start(false); subject.stop }
+
+      it 'returns false' do
+        subject.should_not be_started
+      end
+    end
+
+    context 'with a started adapter' do
+      before { subject.start(false) }
+      after { subject.start }
+
+      it 'returns true' do
+        subject.should be_started
+      end
+    end
+  end
 end
 
 shared_examples_for 'an adapter that call properly listener#on_change' do |*args|