From d1c7b8c6cec16e9227c5db80adb001f352e90ff6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wojciech=20Szara=C5=84ski?=
 <67064139+wszaranski@users.noreply.github.com>
Date: Thu, 10 Jun 2021 17:20:29 +0200
Subject: [PATCH] Add GETDEL command

Redis 6.2.0 added GETDEL command.

See: https://redis.io/commands/getdel
---
 README.md          |  1 +
 cmd_string.go      | 36 ++++++++++++++++++++++++++++++++++++
 cmd_string_test.go | 45 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+)

diff --git a/README.md b/README.md
index ba959bd4..5b498c4a 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,7 @@ Implemented commands:
    - GETBIT
    - GETRANGE
    - GETSET
+   - GETDEL
    - INCR
    - INCRBY
    - INCRBYFLOAT
diff --git a/cmd_string.go b/cmd_string.go
index 09d4577a..f21be84d 100644
--- a/cmd_string.go
+++ b/cmd_string.go
@@ -23,6 +23,7 @@ func commandsString(m *Miniredis) {
 	m.srv.Register("GET", m.cmdGet)
 	m.srv.Register("GETRANGE", m.cmdGetrange)
 	m.srv.Register("GETSET", m.cmdGetset)
+	m.srv.Register("GETDEL", m.cmdGetdel)
 	m.srv.Register("INCRBYFLOAT", m.cmdIncrbyfloat)
 	m.srv.Register("INCRBY", m.cmdIncrby)
 	m.srv.Register("INCR", m.cmdIncr)
@@ -394,6 +395,41 @@ func (m *Miniredis) cmdGetset(c *server.Peer, cmd string, args []string) {
 	})
 }
 
+// GETDEL
+func (m *Miniredis) cmdGetdel(c *server.Peer, cmd string, args []string) {
+	if len(args) != 1 {
+		setDirty(c)
+		c.WriteError(errWrongNumber(cmd))
+		return
+	}
+	if !m.handleAuth(c) {
+		return
+	}
+	if m.checkPubsub(c, cmd) {
+		return
+	}
+
+	withTx(m, c, func(c *server.Peer, ctx *connCtx) {
+		db := m.db(ctx.selectedDB)
+
+		key := args[0]
+
+		if !db.exists(key) {
+			c.WriteNull()
+			return
+		}
+
+		if db.t(key) != "string" {
+			c.WriteError(msgWrongType)
+			return
+		}
+
+		v := db.stringGet(key)
+		db.del(key, true)
+		c.WriteBulk(v)
+	})
+}
+
 // MGET
 func (m *Miniredis) cmdMget(c *server.Peer, cmd string, args []string) {
 	if len(args) < 1 {
diff --git a/cmd_string_test.go b/cmd_string_test.go
index ee43873e..28ee523e 100644
--- a/cmd_string_test.go
+++ b/cmd_string_test.go
@@ -787,6 +787,51 @@ func TestGetSet(t *testing.T) {
 	}
 }
 
+func TestGetdel(t *testing.T) {
+	s, err := Run()
+	ok(t, err)
+	defer s.Close()
+	c, err := proto.Dial(s.Addr())
+	ok(t, err)
+	defer c.Close()
+
+	// Missing key
+	{
+		mustNil(t, c, "GETDEL", "foo")
+	}
+
+	// Existing key
+	{
+		s.Set("foo", "bar")
+		mustDo(t, c,
+			"GETDEL", "foo",
+			proto.String("bar"),
+		)
+		must0(t, c, "EXISTS", "foo")
+	}
+
+	// Wrong type of existing key
+	{
+		s.HSet("wrong", "foo", "bar")
+		mustDo(t, c,
+			"GETDEL", "wrong",
+			proto.Error(msgWrongType),
+		)
+	}
+
+	// Wrong usage
+	{
+		mustDo(t, c,
+			"GETDEL",
+			proto.Error(errWrongNumber("getdel")),
+		)
+		mustDo(t, c,
+			"GETDEL", "foo", "bar",
+			proto.Error(errWrongNumber("getdel")),
+		)
+	}
+}
+
 func TestStrlen(t *testing.T) {
 	s, err := Run()
 	ok(t, err)