Merge pull request #1327 from a5-stable/hscan-novalue-option

Add novalues option support for HSCAN command

Author: byroot

lib/redis/commands/hashes.rb

@@ -220,13 +220,20 @@ def hgetall(key)
       # @param [Hash] options
       #   - `:match => String`: only return keys matching the pattern
       #   - `:count => Integer`: return count keys at most per iteration
+      #   - `:novalues => Boolean`: whether or not to include values in the output (default: false)
       #
-      # @return [String, Array<[String, String]>] the next cursor and all found keys
+      # @return [String, Array<[String, String]>, Array<String>] the next cursor and all found keys
+      #   - when `:novalues` is false: [cursor, [[field1, value1], [field2, value2], ...]]
+      #   - when `:novalues` is true: [cursor, [field1, field2, ...]]
       #
       # See the [Redis Server HSCAN documentation](https://redis.io/docs/latest/commands/hscan/) for further details
       def hscan(key, cursor, **options)
         _scan(:hscan, cursor, [key], **options) do |reply|
-          [reply[0], reply[1].each_slice(2).to_a]
+          if options[:novalues]
+            reply
+          else
+            [reply[0], reply[1].each_slice(2).to_a]
+          end
         end
       end
 
@@ -239,6 +246,7 @@ def hscan(key, cursor, **options)
       # @param [Hash] options
       #   - `:match => String`: only return keys matching the pattern
       #   - `:count => Integer`: return count keys at most per iteration
+      #   - `:novalues => Boolean`: whether or not to include values in the output (default: false)
       #
       # @return [Enumerator] an enumerator for all found keys
       #

lib/redis/commands/keys.rb

@@ -447,13 +447,14 @@ def type(key)
 
       private
 
-      def _scan(command, cursor, args, match: nil, count: nil, type: nil, &block)
+      def _scan(command, cursor, args, match: nil, count: nil, type: nil, novalues: false, &block)
         # SSCAN/ZSCAN/HSCAN already prepend the key to +args+.
 
         args << cursor
         args << "MATCH" << match if match
         args << "COUNT" << Integer(count) if count
         args << "TYPE" << type if type
+        args << "NOVALUES" if novalues
 
         send_command([command] + args, &block)
       end

test/redis/scanning_test.rb

@@ -213,6 +213,26 @@ def test_hscan_with_encoding
     end
   end
 
+  def test_hscan_novalues
+    target_version "7.4.0" do
+      count = 1000
+      elements = []
+      count.times { |j| elements << "key:#{j}" << j.to_s }
+      r.hmset "hash", *elements
+
+      cursor = 0
+      all_keys = []
+      loop do
+        cursor, keys = r.hscan "hash", cursor, novalues: true
+        all_keys.concat keys
+        break if cursor == "0"
+      end
+
+      assert_equal count, all_keys.uniq.size
+      assert_equal true, all_keys.all? { |k| k.start_with?("key:") }
+    end
+  end
+
   def test_hscan_each_enumerator
     count = 1000
     elements = []
@@ -270,6 +290,25 @@ def test_hscan_each_block_match
     assert all_keys.sort == keys_from_scan.uniq.sort
   end
 
+  def test_hscan_each_block_novalues
+    target_version "7.4.0" do
+      count = 1000
+      elements = []
+      count.times { |j| elements << "key:#{j}" << j.to_s }
+      r.hmset "hash", *elements
+
+      keys = []
+      values = []
+      r.hscan_each("hash", novalues: true) do |field, value|
+        keys << field
+        values << value
+      end
+
+      assert_equal count, keys.uniq.size
+      assert_equal true, values.all?(&:nil?)
+    end
+  end
+
   def test_zscan_with_encoding
     %i[ziplist skiplist].each do |enc|
       r.del "zset"