✨ Add SINTERCARD

lib/redis/commands/sets.rb

@@ -154,6 +154,19 @@ def sinterstore(destination, *keys)
         send_command([:sinterstore, destination].concat(keys))
       end
 
+      # This command is similar to SINTER, but instead of returning the result set,
+      #   it returns just the cardinality of the result.
+      #
+      # @param [String, Array<String>] keys keys pointing to sets to intersect
+      # @param [Interger] limits number of matches searched for
+      # @return [Array<String>] cardinality of the intersection
+      def sintercard(*keys, limit: nil)
+        args = [:sintercard, keys.size, keys]
+        args << "LIMIT" << limit if limit
+
+        send_command(args)
+      end
+
       # Add multiple sets.
       #
       # @param [String, Array<String>] keys keys pointing to sets to unify

lib/redis/distributed.rb

@@ -648,6 +648,15 @@ def sinterstore(destination, *keys)
       end
     end
 
+    # This command is similar to SINTER, but instead of returning the result set,
+    #   it returns just the cardinality of the result.
+    def sintercard(*keys, limit: nil)
+      keys.flatten!(1)
+      ensure_same_node(:sintercard, keys) do |node|
+        node.sinter(*keys, limit: limit)
+      end
+    end
+
     # Add multiple sets.
     def sunion(*keys)
       keys.flatten!(1)

test/lint/sets.rb

@@ -237,6 +237,14 @@ def test_variadic_sinterstore_expand
       assert_equal 1, r.sinterstore('{1}baz', '{1}foo', '{1}bar')
     end
 
+    def test_sintercard
+      r.sadd '{1}foo', 's1'
+      r.sadd '{1}foo', 's2'
+      r.sadd '{1}bar', 's2'
+
+      assert_equal 1, r.sintercard('{1}foo', '{1}bar')
+    end
+
     def test_sunion
       r.sadd 'foo', 's1'
       r.sadd 'foo', 's2'