PLT-7684 Add support to outgoing webhooks and slash commands to set post type and props (#7531)

* Add support to outgoing webhooks and slash commands to set post type and props

* Fix nil access

api4/command.go

@@ -305,6 +305,8 @@ func testCommand(c *Context, w http.ResponseWriter, r *http.Request) {
 	rc := &model.CommandResponse{
 		Text:         "test command response " + msg,
 		ResponseType: model.COMMAND_RESPONSE_TYPE_IN_CHANNEL,
+		Type:         "custom_test",
+		Props:        map[string]interface{}{"someprop": "somevalue"},
 	}
 
 	w.Write([]byte(rc.ToJson()))

api4/command_test.go

@@ -423,6 +423,14 @@ func TestExecuteCommand(t *testing.T) {
 	cmdPosted := false
 	for _, post := range posts.Posts {
 		if strings.Contains(post.Message, "test command response") {
+			if post.Type != "custom_test" {
+				t.Fatal("wrong type set in slash command post")
+			}
+
+			if post.Props["someprop"] != "somevalue" {
+				t.Fatal("wrong prop set in slash command post")
+			}
+
 			cmdPosted = true
 			break
 		}