From 90654432b00845ff46e9f6380dd0ac463b13bb6f Mon Sep 17 00:00:00 2001
From: fatkodima <fatkodima123@gmail.com>
Date: Thu, 4 Nov 2021 22:30:22 +0200
Subject: [PATCH] [Redis 6.2] Add COPY command

---
 lib/redis.rb                                  | 35 ++++++++++++++++++
 lib/redis/distributed.rb                      |  7 ++++
 test/cluster_commands_on_value_types_test.rb  |  4 +++
 ...istributed_commands_on_value_types_test.rb |  8 +++++
 test/helper.rb                                |  5 +++
 test/lint/value_types.rb                      | 36 +++++++++++++++++++
 6 files changed, 95 insertions(+)

diff --git a/lib/redis.rb b/lib/redis.rb
index 4746ec463..353726555 100644
--- a/lib/redis.rb
+++ b/lib/redis.rb
@@ -656,6 +656,41 @@ def move(key, db)
     end
   end
 
+  # Copy a value from one key to another.
+  #
+  # @example Copy a value to another key
+  #   redis.set "foo", "value"
+  #     # => "OK"
+  #   redis.copy "foo", "bar"
+  #     # => true
+  #   redis.get "bar"
+  #     # => "value"
+  #
+  # @example Copy a value to a key in another database
+  #   redis.set "foo", "value"
+  #     # => "OK"
+  #   redis.copy "foo", "bar", db: 2
+  #     # => true
+  #   redis.select 2
+  #     # => "OK"
+  #   redis.get "bar"
+  #     # => "value"
+  #
+  # @param [String] source
+  # @param [String] destination
+  # @param [Integer] db
+  # @param [Boolean] replace removes the `destination` key before copying value to it
+  # @return [Boolean] whether the key was copied or not
+  def copy(source, destination, db: nil, replace: false)
+    command = [:copy, source, destination]
+    command << "DB" << db if db
+    command << "REPLACE" if replace
+
+    synchronize do |client|
+      client.call(command, &Boolify)
+    end
+  end
+
   def object(*args)
     synchronize do |client|
       client.call([:object] + args)
diff --git a/lib/redis/distributed.rb b/lib/redis/distributed.rb
index 4662a136d..c199a12cd 100644
--- a/lib/redis/distributed.rb
+++ b/lib/redis/distributed.rb
@@ -215,6 +215,13 @@ def move(key, db)
       node_for(key).move(key, db)
     end
 
+    # Copy a value from one key to another.
+    def copy(source, destination, **options)
+      ensure_same_node(:copy, [source, destination]) do |node|
+        node.copy(source, destination, **options)
+      end
+    end
+
     # Return a random key from the keyspace.
     def randomkey
       raise CannotDistribute, :randomkey
diff --git a/test/cluster_commands_on_value_types_test.rb b/test/cluster_commands_on_value_types_test.rb
index 257e4dd2e..07a369206 100644
--- a/test/cluster_commands_on_value_types_test.rb
+++ b/test/cluster_commands_on_value_types_test.rb
@@ -11,4 +11,8 @@ class TestClusterCommandsOnValueTypes < Minitest::Test
   def test_move
     assert_raises(Redis::CommandError) { super }
   end
+
+  def test_copy
+    assert_raises(Redis::CommandError) { super }
+  end
 end
diff --git a/test/distributed_commands_on_value_types_test.rb b/test/distributed_commands_on_value_types_test.rb
index f882537b5..e15b7f52d 100644
--- a/test/distributed_commands_on_value_types_test.rb
+++ b/test/distributed_commands_on_value_types_test.rb
@@ -127,4 +127,12 @@ def test_migrate
       r.migrate("foo", {})
     end
   end
+
+  def test_copy
+    r.set("foo", "s1")
+
+    assert_raises Redis::Distributed::CannotDistribute do
+      r.copy("foo", "bar")
+    end
+  end
 end
diff --git a/test/helper.rb b/test/helper.rb
index 0a98354db..d99f5af50 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -158,6 +158,11 @@ def target_version(target)
       end
     end
 
+    def with_db(index)
+      r.select(index)
+      yield
+    end
+
     def omit_version(min_ver)
       skip("Requires Redis > #{min_ver}") if version < min_ver
     end
diff --git a/test/lint/value_types.rb b/test/lint/value_types.rb
index e23715b7c..66b88818f 100644
--- a/test/lint/value_types.rb
+++ b/test/lint/value_types.rb
@@ -162,5 +162,41 @@ def test_move
       assert_equal "s1", r.get("foo")
       assert_equal "s3", r.get("bar")
     end
+
+    def test_copy
+      target_version("6.2") do
+        with_db(14) do
+          r.flushdb
+
+          r.set "foo", "s1"
+          r.set "bar", "s2"
+
+          assert r.copy("foo", "baz")
+          assert_equal "s1", r.get("baz")
+
+          assert !r.copy("foo", "bar")
+          assert r.copy("foo", "bar", replace: true)
+          assert_equal "s1", r.get("bar")
+        end
+
+        with_db(15) do
+          r.set "foo", "s3"
+          r.set "bar", "s4"
+        end
+
+        with_db(14) do
+          assert r.copy("foo", "baz", db: 15)
+          assert_equal "s1", r.get("foo")
+
+          assert !r.copy("foo", "bar", db: 15)
+          assert r.copy("foo", "bar", db: 15, replace: true)
+        end
+
+        with_db(15) do
+          assert_equal "s1", r.get("baz")
+          assert_equal "s1", r.get("bar")
+        end
+      end
+    end
   end
 end