Merge pull request #708 from estolfo/RUBY-1054-cmd-read

RUBY-1054 Use primary server selector for command unless read pref in opts

Author: estolfo

lib/mongo/database.rb

@@ -148,8 +148,8 @@ def collections
     #
     # @return [ Hash ] The result of the command execution.
     def command(operation, opts = {})
-      preference = opts[:read] ? ServerSelector.get(client.options.merge(opts[:read])) : read_preference
-      server = preference.select_server(cluster)
+      preference = ServerSelector.get(client.options.merge(opts[:read])) if opts[:read]
+      server = preference ? preference.select_server(cluster) : cluster.next_primary
       Operation::Command.new({
         :selector => operation,
         :db_name => name,

spec/mongo/database_spec.rb

@@ -228,6 +228,18 @@
         end.to raise_error(Mongo::Error::NoServerAvailable)
       end
     end
+
+    context 'when there is a read preference set on the client' do
+
+      let(:database) do
+        described_class.new(authorized_client.with(read: { mode: :secondary }), TEST_DB)
+      end
+
+      it 'does not use the read preference' do
+        expect(database.client.cluster).to receive(:next_primary).and_call_original
+        database.command(ping: 1)
+      end
+    end
   end
 
   describe '#drop' do