fix: correctly handle ignored 'combine' rule

Fixes: pact-foundation/pact-ruby-standalone#25

lib/pact/matching_rules/v3/merge.rb

@@ -116,7 +116,7 @@ def log_ignored_rules
           if @matching_rules.any?
             @matching_rules.each do | path, rules_hash |
               rules_hash.each do | key, value |
-                $stderr.puts "WARN: Ignoring unsupported #{key} #{value} for path #{path}" if value.any?
+                $stderr.puts "WARN: Ignoring unsupported #{key} #{value} for path #{path}" if value_present?(value)
               end
             end
           end
@@ -129,6 +129,10 @@ def find_rule(path, key)
         def log_used_rule path, key, value
           @used_rules << [path, key, value]
         end
+
+        def value_present? value
+          value.respond_to?(:any?) ? value.any? : true
+        end
       end
     end
   end

spec/lib/pact/matching_rules/v3/merge_spec.rb

@@ -456,6 +456,29 @@ module V3
           end
         end
 
+        describe "with a combine key" do
+          let(:expected) do
+            {
+              "foo" => "bar"
+            }
+          end
+
+          let(:matching_rules) do
+            {
+              "$.foo" => {
+                "matchers" => [{ "match" => "type" }],
+                "combine" => "AND"
+              }
+            }
+
+          end
+
+          it "logs the ignored rule" do
+            allow(Pact.configuration.error_stream).to receive(:puts)
+            expect(Pact.configuration.error_stream).to receive(:puts).with("WARN: Ignoring unsupported combine AND for path $['foo']")
+            subject
+          end
+        end
       end
     end
   end