feat: add warnings for errors 401 and 409 (#574)

* feat: add warnings for errors 401 and 409

* fix: dedupe errors during polling

* fix: remove testing code

revoked, don't bother

src/bot.ts

@@ -568,15 +568,8 @@ a known bot info object.",
  let sleepSeconds = 3;
  if (error instanceof GrammyError) {
  debugErr(error.message);
- if (error.error_code === 401) {
- debugErr(
- "Make sure you are using the bot token you obtained from @BotFather (https://t.me/BotFather).",
- );
- throw error;
- } else if (error.error_code === 409) {
- debugErr(
- "Consider revoking the bot token if you believe that no other instance is running.",
- );
+ // rethrow upon unauthorized or conflict
+ if (error.error_code === 401 || error.error_code === 409) {
  throw error;
  } else if (error.error_code === 429) {
  debugErr("Bot API server is closing.");

src/core/error.ts

@@ -1,4 +1,6 @@
 import { type ApiError, type ResponseParameters } from "../types.ts";
+import { debug as d } from "../platform.deno.ts";
+const debug = d("grammy:warn");
 
 /**
  * This class represents errors that are thrown by grammY because the Telegram
@@ -40,6 +42,18 @@ export function toGrammyError(
  method: string,
  payload: Record<string, unknown>,
 ) {
+ switch (err.error_code) {
+ case 401:
+ debug(
+ "Error 401 means that your bot token is wrong, talk to https://t.me/BotFather to check it.",
+ );
+ break;
+ case 409:
+ debug(
+ "Error 409 means that you are running your bot several times on long polling. Consider revoking the bot token if you believe that no other instance is running.",
+ );
+ break;
+ }
  return new GrammyError(
  `Call to '${method}' failed!`,
  err,