support ping command

internal/command/command.go

@@ -49,6 +49,8 @@ func Parse(args [][]byte) (redis.Cmd, error) {
  // connection
  case "echo":
  return conn.ParseEcho(b)
+ case "ping":
+ return conn.ParsePing(b)
 
  // key
  case "del":

internal/command/conn/ping.go

@@ -0,0 +1,41 @@
+package conn
+
+import (
+ "strings"
+
+ "github.com/nalgeon/redka/internal/parser"
+ "github.com/nalgeon/redka/internal/redis"
+)
+
+const (
+ PONG = "PONG"
+)
+
+// Returns PONG if no argument is provided, otherwise return a copy of the argument as a bulk
+// https://redis.io/commands/ping
+type Ping struct {
+ redis.BaseCmd
+ Parts []string
+}
+
+
+func ParsePing(b redis.BaseCmd) (*Ping, error) {
+ cmd := &Ping{BaseCmd: b}
+ err := parser.New(
+ parser.Strings(&cmd.Parts),
+ ).Required(0).Run(cmd.Args())
+ if err != nil {
+ return cmd, err
+ }
+ return cmd, nil
+}
+
+func (c *Ping) Run(w redis.Writer, _ redis.Redka) (any, error) {
+ if len(c.Parts) == 0 {
+ w.WriteAny(PONG)
+ return PONG, nil
+ }
+ out := strings.Join(c.Parts, " ")
+ w.WriteAny(out)
+ return out, nil
+}

internal/command/conn/ping_test.go

@@ -0,0 +1,89 @@
+package conn_test
+
+import (
+ "testing"
+
+ "github.com/nalgeon/redka/internal/command"
+ "github.com/nalgeon/redka/internal/command/conn"
+ "github.com/nalgeon/redka/internal/redis"
+ "github.com/nalgeon/redka/internal/testx"
+)
+
+func TestPingParse(t *testing.T) {
+ tests := []struct {
+ name string
+ args [][]byte
+ want []string
+ err error
+ }{
+ {
+ name: "ping",
+ args: command.BuildArgs("ping"),
+ want: []string(nil),
+ err: nil,
+ },
+ {
+ name: "ping hello",
+ args: command.BuildArgs("ping", "hello"),
+ want: []string{"hello"},
+ err: nil,
+ },
+ {
+ name: "ping one two",
+ args: command.BuildArgs("ping", "one", "two"),
+ want: []string{"one", "two"},
+ err: nil,
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ cmd, err := command.Parse(test.args)
+ testx.AssertEqual(t, err, test.err)
+ if err == nil {
+ testx.AssertEqual(t, cmd.(*conn.Ping).Parts, test.want)
+ }
+ })
+ }
+}
+
+func TestPingExec(t *testing.T) {
+ db, red := getDB(t)
+ defer db.Close()
+
+ tests := []struct {
+ name string
+ cmd *conn.Ping
+ res any
+ out string
+ }{
+ {
+ name: "ping",
+ cmd: command.MustParse[*conn.Ping]("ping"),
+ res: "PONG",
+ out: "PONG",
+ },
+ {
+ name: "ping hello",
+ cmd: command.MustParse[*conn.Ping]("ping hello"),
+ res: "hello",
+ out: "hello",
+ },
+ {
+ name: "ping one two",
+ cmd: command.MustParse[*conn.Ping]("ping one two"),
+ res: "one two",
+ out: "one two",
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ conn := redis.NewFakeConn()
+ res, err := test.cmd.Run(conn, red)
+ testx.AssertNoErr(t, err)
+ testx.AssertEqual(t, res, test.res)
+ testx.AssertEqual(t, conn.Out(), test.out)
+ })
+ }
+}