raise a couchrest specific error if connection to the database fails

lib/couchrest/model/connection.rb

@@ -33,6 +33,10 @@ def prepare_database(db = nil)
           else
             db
           end
+        rescue RestClient::Unauthorized,
+          Errno::EHOSTUNREACH,
+          Errno::ECONNREFUSED => e
+          raise CouchRest::Model::ConnectionFailed.new(e.to_s)
         end
 
         protected

lib/couchrest/model/errors.rb

@@ -20,6 +20,13 @@ def initialize(document)
       end
     end
 
+    # Raised when the connection to the couch server can not be established.
+    #
+    # The message will contain the corresponding error message from the
+    # underlying error.
+    #
+    class ConnectionFailed < CouchRestModelError; end
+
     class DocumentNotFound < Errors::CouchRestModelError; end
   end
 end