✨ Add ZINTERCARD

lib/redis/commands/sorted_sets.rb

@@ -722,6 +722,18 @@ def zinterstore(*args)
       end
       ruby2_keywords(:zinterstore) if respond_to?(:ruby2_keywords, true)
 
+      # This command is similar to ZINTER, but instead of returning the result set,
+      #   it returns just the cardinality of the result.
+      #
+      # @param [Array<String>] keys list of sorted sets
+      # @param [Integer] limit will short circuit operation if limit is met
+      def zintercard(*keys, limit: nil)
+        args = [:zintercard, keys.size, keys]
+        args << "LIMIT" << limit if limit
+
+        send_command(args)
+      end
+
       # Return the union of multiple sorted sets
       #
       # @example Retrieve the union of `2*zsetA` and `1*zsetB`

lib/redis/distributed.rb

@@ -788,6 +788,14 @@ def zinterstore(destination, *keys, **options)
       end
     end
 
+    # This command is similar to ZINTER, but instead of returning the result set,
+    #   it returns just the cardinality of the result.
+    def zintercard(*keys, limit: nil)
+      ensure_same_node(:zintercard, keys) do |node|
+        node.zintercard(keys, limit)
+      end
+    end
+
     # Return the union of multiple sorted sets.
     def zunion(*keys, **options)
       keys.flatten!(1)

test/lint/sorted_sets.rb

@@ -786,6 +786,17 @@ def test_zinterstore_expand
       assert_equal 1, r.zinterstore('{1}baz', %w[{1}foo {1}bar], weights: [2.0, 3.0])
     end
 
+    def test_zintercard
+      target_version('7.0') do
+        r.zadd('{1}foo', %w[0 a 1 b 2 c 3 d])
+        assert_equal 0, r.zintercard('{1}foo', '{2}foo2')
+
+        r.zadd('{2}foo', %w[0 a 1 b 2 c])
+        assert_equal 3, r.zintercard('{1}foo', '{2}foo2')
+        assert_equal 2, r.zintercard('{1}foo', '{2}foo2', limit: 2)
+      end
+    end
+
     def test_zscan
       r.zadd('foo', %w[0 a 1 b 2 c])
       expected = ['0', [['a', 0.0], ['b', 1.0], ['c', 2.0]]]