Better documentation on testing socketmode client

[dnck]

Description

I'm struggling to test my socketmode client. Ideally, I want to mock the slack server, and send different events to my connected client. I found the current docs on testserver, but didn't quite understand how to get it all wired up and I ended up writing my own mock websocket server, which still isn't working 100% but I got further than using the testserver. Is there any better documentation on testing a socketmode client? Alternatively, can one of the maintainers talk to me in this thread, and help me make a contribution to documenting how to do so for the community benefit?

[nlopes]

Hi @dnck,

The best approach, I think, would be to do something like the following:

[...]
import (
	"net/http"
	"fmt"
	"os"
	"time"

	"github.com/slack-go/slack"
	"github.com/slack-go/slack/slackevents"
	"github.com/slack-go/slack/slacktest"
	"github.com/slack-go/slack/socketmode"
)

func appsConnectionOpenHandler(wsURL string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusOK)
		fmt.Fprint(w, `{"ok": true, "url":"`+wsURL+`"}`)
	}
}

func main() {
	s := slacktest.NewTestServer()
	go s.Start()

	s.Handle("/apps.connections.open", appsConnectionOpenHandler(s.GetWSURL()))

	api := slack.New("DOES NOT MATTER", slack.OptionAPIURL(s.GetAPIURL()))
	client := socketmode.New(api)

        // This is just an example! I'm basically waiting a few seconds and then sending a message to the websocket from the server side (think of it as Slack sending your client a message)
	go func() {
		time.Sleep(3 * time.Second)
		s.SendToWebsocket(`
{
  "payload": {
    "type": "message",
	"channel": "C12345",
	"user": "W012A3CDE",
	"text": "Hello, world!",
	"ts": "1742665072",
	"username": "Egon Spengler",
	"replace_original": false,
	"delete_original": false,
	"metadata": {
	  "event_type": "",
	  "event_payload": null
	},
	"blocks": null
  },
  "envelope_id": "1-2-3",
  "type": "events_api",
  "accepts_response_payload": false
}
`)
		time.Sleep(3 * time.Second)
	}()

        // This is the core of your client... mostly a copy&paste from what's in examples/socketmode/socketmode.go
	go func() {
		for evt := range client.Events {
			switch evt.Type {
			case socketmode.EventTypeConnecting:
				fmt.Println("Connecting to Slack with Socket Mode...")
			case socketmode.EventTypeConnectionError:
				fmt.Println("Connection failed. Retrying later...")
			case socketmode.EventTypeConnected:
				fmt.Println("Connected to Slack with Socket Mode.")
                         [...]
                 }
	}()

	client.Run()
}

Hope this helps!