added Do method for raw query by single conn from pool.Conn() (#3182)

* added `Do` method for raw query by single conn from `pool.Conn()`

* added test to cmdble Do method

* fixed test

* moved Do cmd to commands.go

---------

Co-authored-by: Oleg Laktyushkin <[email protected]>
Co-authored-by: Nedyalko Dyakov <[email protected]>

Author: 3 people

Diff for: commands.go

@@ -422,6 +422,12 @@ func (c cmdable) Ping(ctx context.Context) *StatusCmd {
 	return cmd
 }
 
+func (c cmdable) Do(ctx context.Context, args ...interface{}) *Cmd {
+	cmd := NewCmd(ctx, args...)
+	_ = c(ctx, cmd)
+	return cmd
+}
+
 func (c cmdable) Quit(_ context.Context) *StatusCmd {
 	panic("not implemented")
 }

Diff for: commands_test.go

@@ -84,6 +84,12 @@ var _ = Describe("Commands", func() {
 			Expect(ping.Val()).To(Equal("PONG"))
 		})
 
+		It("should Ping with Do method", func() {
+			result := client.Conn().Do(ctx, "PING")
+			Expect(result.Err()).NotTo(HaveOccurred())
+			Expect(result.Val()).To(Equal("PONG"))
+		})
+
 		It("should Wait", func() {
 			const wait = 3 * time.Second