Merge pull request #642 from estolfo/wire-version

Correct wire version range checks

Author: estolfo

lib/mongo/server/description/features.rb

@@ -75,7 +75,8 @@ def initialize(server_wire_versions)
         private
 
         def check_driver_support!
-          if DRIVER_WIRE_VERSIONS.max < server_wire_versions.max
+          if DRIVER_WIRE_VERSIONS.max < server_wire_versions.min ||
+             DRIVER_WIRE_VERSIONS.min > server_wire_versions.max
             raise Error::UnsupportedFeatures.new(server_wire_versions)
           end
         end

spec/mongo/server/description/features_spec.rb

@@ -15,16 +15,36 @@
       end
     end
 
-    context 'when the server wire version range is higher' do
+    context 'when the server wire version range min is higher' do
 
       it 'raises an exception' do
         expect {
-          described_class.new(0..4)
+          described_class.new(described_class::DRIVER_WIRE_VERSIONS.max+1..described_class::DRIVER_WIRE_VERSIONS.max+2)
         }.to raise_error(Mongo::Error::UnsupportedFeatures)
       end
     end
 
-    context 'when the server wire version range is lower' do
+    context 'when the server wire version range max is higher' do
+
+      let(:features) do
+        described_class.new(0..4)
+      end
+
+      it 'sets the server wire version range' do
+        expect(features.server_wire_versions).to eq(0..4)
+      end
+    end
+
+    context 'when the server wire version range max is lower' do
+
+      it 'raises an exception' do
+        expect {
+          described_class.new(described_class::DRIVER_WIRE_VERSIONS.min-2..described_class::DRIVER_WIRE_VERSIONS.min-1)
+        }.to raise_error(Mongo::Error::UnsupportedFeatures)
+      end
+    end
+
+    context 'when the server wire version range max is lower' do
 
       let(:features) do
         described_class.new(0..2)