expiry with options

command.go

@@ -5,7 +5,7 @@ import (
 	"time"
 )
 
-// Flags For SETOptions
+// Flags For SETOptions.
 const (
 	// NX only sets the key if it does not already exist.
 	NX = 1 << iota
@@ -18,6 +18,14 @@ const (
 	PX
 )
 
+// EXPIRE flags include NX And XX.
+const (
+	// GT sets expiry only when the new expiry is greater than current one.
+	GT = 32 << iota
+	// LT sets expiry only when the new expiry is less than current one.
+	LT
+)
+
 // SETOptions are extra arguments for the SET command.
 type SETOptions struct {
 	// Composotion of NX, XX, EX or PX. The combinations
@@ -48,6 +56,32 @@ func (c *Client[Key, Value]) FLUSHDB(async bool) error {
 	return c.commandOK(r)
 }
 
+// EXPIRE executes <https://redis.io/commands/expire>.
+// Flags can be any of NX, XX, GT or LT.
+func (c *Client[Key, Value]) EXPIRE(k Key, seconds int64, flags uint) (bool, error) {
+	if unknown := flags &^ (NX | XX | GT | LT); unknown != 0 {
+		return false, errors.New("redis: unknown EXPIRE flags")
+	}
+
+	var n int64
+	var err error
+	switch flags {
+	case 0:
+		n, err = c.commandInteger(requestWithStringAndDecimal("*3\r\n$6\r\nEXPIRE\r\n$", k, seconds))
+	case NX:
+		n, err = c.commandInteger(requestWithStringAndDecimalAndString("*4\r\n$6\r\nEXPIRE\r\n$", k, seconds, "NX"))
+	case XX:
+		n, err = c.commandInteger(requestWithStringAndDecimalAndString("*4\r\n$6\r\nEXPIRE\r\n$", k, seconds, "XX"))
+	case GT:
+		n, err = c.commandInteger(requestWithStringAndDecimalAndString("*4\r\n$6\r\nEXPIRE\r\n$", k, seconds, "GT"))
+	case LT:
+		n, err = c.commandInteger(requestWithStringAndDecimalAndString("*4\r\n$6\r\nEXPIRE\r\n$", k, seconds, "LT"))
+	default:
+		return false, errors.New("redis: multiple EXPIRE flags denied")
+	}
+	return n != 0, err
+}
+
 // FLUSHALL executes <https://redis.io/commands/flushall>.
 func (c *Client[Key, Value]) FLUSHALL(async bool) error {
 	var r *request

command_test.go

@@ -670,3 +670,51 @@ func TestHashAbsent(t *testing.T) {
 		t.Errorf("HDEL %q got true, want false", key)
 	}
 }
+
+func TestExpiry(t *testing.T) {
+	t.Parallel()
+	key := randomKey("test-key")
+
+	ok, err := testClient.EXPIRE(key, 2, 0)
+	if err != nil {
+		t.Errorf("EXPIRE %q 2 error: %s", key, err)
+	} else if ok {
+		t.Errorf("EXPIRE %q 2 got OK on non-existent key", key)
+	}
+	_, err = testClient.SADD(key, "foo")
+	if err != nil {
+		t.Errorf(`SADD %q "foo" error: %s`, key, err)
+	}
+	ok, err = testClient.EXPIRE(key, 2, 0)
+	if err != nil {
+		t.Errorf("EXPIRE %q 2 error: %s", key, err)
+	} else if !ok {
+		t.Errorf("EXPIRE %q 2 got not OK on existent key", key)
+	}
+
+	ok, err = testClient.EXPIRE(key, 2, NX)
+	if err != nil {
+		t.Errorf("EXPIRE %q 2 NX error: %s", key, err)
+	} else if ok {
+		t.Errorf("EXPIRE %q 2 NX got OK with existing expiry", key)
+	}
+	ok, err = testClient.EXPIRE(key, 2, XX)
+	if err != nil {
+		t.Errorf("EXPIRE %q 2 XX error: %s", key, err)
+	} else if !ok {
+		t.Errorf("EXPIRE %q 2 XX got not OK with existing expiry", key)
+	}
+
+	ok, err = testClient.EXPIRE(key, 99, LT)
+	if err != nil {
+		t.Errorf("EXPIRE %q 99 LT error: %s", key, err)
+	} else if ok {
+		t.Errorf("EXPIRE %q 99 LT got OK on 2 second expiry", key)
+	}
+	ok, err = testClient.EXPIRE(key, 99, GT)
+	if err != nil {
+		t.Errorf("EXPIRE %q 99 GT error: %s", key, err)
+	} else if !ok {
+		t.Errorf("EXPIRE %q 99 GT got not OK on 2 second expiry", key)
+	}
+}