WIP test but i think im done

src/config.go

@@ -149,9 +149,10 @@ func (c Config) WithConn(hashKey string, foo func(net.Conn) error) error {
 		log.Printf("errored with conn %v: %v", hashIdx, err)
 		forwardConn.Close()
 		return err
+	} else {
+		log.Printf("release conn %v", hashIdx)
+		forward.Put(forwardConn)
 	}
 
-	log.Printf("release conn %v", hashIdx)
-	forward.Put(forwardConn)
 	return nil
 }

src/listen_test.go

@@ -0,0 +1,54 @@
+package src
+
+import (
+	"context"
+	"encoding/base64"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestListenLifecycle(t *testing.T) {
+	ctx, can := context.WithTimeout(context.Background(), time.Second*5)
+	defer can()
+
+	valkeyPort := getPort(t)
+	valkeyReady := make(chan struct{})
+	valkeyReadyCloserOnce := &sync.Once{}
+	go func() {
+		defer close(valkeyReady)
+		t.Fatal("not impl: start pretend valkey server")
+	}()
+	select {
+	case <-ctx.Done():
+	case <-valkeyReady:
+	}
+
+	config := Config{
+		ctx:      ctx,
+		Listen:   ":" + getPort(t),
+		Forwards: "127.0.0.1:" + valkeyPort,
+		Hello:    base64.StdEncoding.EncodeToString([]byte("+ping\r\n")),
+	}
+	if err := config.setForwards(); err != nil {
+		t.Fatal(err)
+	}
+
+	go func() {
+		defer can()
+		t.Fatal("not impl: dial listen")
+	}()
+
+	if err := listen(ctx, config); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func getPort(t *testing.T) string {
+	s := httptest.NewServer(http.HandlerFunc(http.NotFound))
+	s.Close()
+	return strings.Split(s.URL, ":")[2]
+}