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// deno-lint-ignore-file camelcaseimport { BotError, Composer, run } from './composer.ts'import { Context } from './context.ts'import { Api } from './core/api.ts'import { ApiClientOptions, WebhookReplyEnvelope } from './core/client.ts'import { GrammyError } from './core/error.ts'import { Update, debug as d, UserFromGetMe } from './platform.ts'const debug = d('grammy:bot')const debugErr = d('grammy:error')
/** * Options that can be specified when running the bot via simple long polling. */export interface PollingOptions { /** * Limits the number of updates to be retrieved per `getUpdates` call. * Values between 1-100 are accepted. Defaults to 100. */ limit?: number /** * Timeout in seconds for long polling. grammY uses 30 seconds as a default * value. */ timeout?: number /** * A list of the update types you want your bot to receive. For example, * specify [“message”, “edited_channel_post”, “callback_query”] to only * receive updates of these types. See Update for a complete list of * available update types. Specify an empty list to receive all update types * except chat_member (default). If not specified, the previous setting will * be used. * * Please note that this parameter doesn't affect updates created before the * call to the getUpdates, so unwanted updates may be received for a short * period of time. */ allowed_updates?: ReadonlyArray<Exclude<keyof Update, 'update_id'>> /** * Pass True to drop all pending updates before starting the long polling. */ drop_pending_updates?: boolean /** * Synchronous callback that is useful for logging. It will be executed once * the setup of the bot has completed, and immediately before the first * updates are being fetched. The bot information `bot.botInfo` will be * available when the function is run. For convenience, the callback * function receives the value of `bot.botInfo` as an argument. */ onStart?: (botInfo: UserFromGetMe) => void}
export { BotError }/** * Error handler that can be installed on a bot to catch error thrown by * middleware. */export type ErrorHandler<C extends Context = Context> = ( error: BotError<C>) => unknown
/** * Options to pass the bot when creating it. */export interface BotConfig<C extends Context> { /** * You can specify a number of advanced options under the `client` property. * The options will be passed to the grammY client—this is the part of * grammY that actually connects to the Telegram Bot API server in the end * when making HTTP requests. */ client?: ApiClientOptions /** * grammY automatically calls `getMe` when starting up to make sure that * your bot has access to the bot's own information. If you restart your bot * often, for example because it is running in a serverless environment, * then you may want to skip this initial API call. * * Set this property of the options to pre-initialize the bot with cached * values. If you use this option, grammY will not attempt to make a `getMe` * call but use the provided data instead. */ botInfo?: UserFromGetMe /** * Pass the constructor of a custom context object that will be used when * creating the context for each incoming update. */ ContextConstructor?: new ( ...args: ConstructorParameters<typeof Context> ) => C}
/** * This is the single most important class of grammY. It represents your bot. * * First, you must create a bot by talking to @BotFather, check out * Once it is ready, you obtain a secret token for your * bot. grammY will use that token to identify as your bot when talking to the * Telegram servers. Got the token? You are now ready to write some code and run * your bot! * * You should do three things to run your bot: * ```ts * // 1. Create a bot instance * const bot = new Bot('<secret-token>') * // 2. Listen for updates * bot.on('message:text', ctx => ctx.reply('You wrote: ' + ctx.message.text)) * // 3. Launch it! * bot.start() * ``` */export class Bot< C extends Context = Context, A extends Api = Api> extends Composer<C> { private pollingRunning = false private pollingAbortController: AbortController | undefined private lastTriedUpdateId = 0
/** * Gives you full access to the Telegram Bot API. * ```ts * // This is how to call the Bot API methods: * bot.api.sendMessage(chat_id, 'Hello, grammY!') * ``` * * Use this only outside of your middleware. If you have access to `ctx`, * then using `ctx.api` instead of `bot.api` is preferred. */ public readonly api: A
private me: UserFromGetMe | undefined private readonly clientConfig: ApiClientOptions | undefined
private readonly ContextConstructor: new ( ...args: ConstructorParameters<typeof Context> ) => C
/** * Holds the bot's error handler that is invoked whenever middleware throws * (rejects). If you set your own error handler via `bot.catch`, all that * happens is that this variable is assigned. */ public errorHandler: ErrorHandler<C> = async err => { console.error( 'Error in middleware while handling update', err.ctx?.update?.update_id, err.error ) console.error('No error handler was set!') console.error('Set your own error handler with `bot.catch = ...`') if (this.pollingRunning) { console.error('Stopping bot') await this.stop() } throw err }
/** * Creates a new Bot with the given token. * * Remember that you can listen for messages by calling * ```ts * bot.on('message', ctx => { ... }) * ``` * or similar methods. * * The simplest way to start your bot is via simple long polling: * ```ts * bot.start() * ``` * * @param token The bot's token as acquired from * @param config Optional configuration properties for the bot */ constructor(public readonly token: string, config?: BotConfig<C>) { super() if (token.length === 0) throw new Error('Empty token!') = config?.botInfo this.clientConfig = config?.client this.ContextConstructor = config?.ContextConstructor ?? (Context as new ( ...args: ConstructorParameters<typeof Context> ) => C) this.api = new Api(token, this.clientConfig) as A }
/** * Information about the bot itself as retrieved from `api.getMe()`. Only * available after the bot has been initialized via `await bot.init()`, or * after the value has been set manually. * * Starting the bot will always perform the initialization automatically, * unless a manual value is already set. * * Note that the recommended way to set a custom bot information object is * to pass it to the configuration object of the `new Bot()` instatiation, * rather than assigning this property. */ public set botInfo(botInfo: UserFromGetMe) { = botInfo } public get botInfo(): UserFromGetMe { if ( === undefined) { throw new Error( 'Bot information unavailable! Make sure to call `await bot.init()` before accessing `bot.botInfo`!' ) } return }
/** * Initializes the bot, i.e. fetches information about the bot itself. This * method is called automatically, you don't have to call it manually. */ async init() { if ( === undefined) { debug('Initializing bot') const me = await this.api.getMe() if ( === undefined) = me else debug('Bot info was set manually by now, will not overwrite') } else { debug('Bot already initialized!') } debug(`I am ${}!`) }
/** * This is an internal method that you probably will not ever need to call. * It is used whenever a new update arrives from the Telegram servers that * your bot will handle. * * If you're writing a library on top of grammY, check out the * [documentation]( of the runner * plugin for an example that uses this method. * * @param update An update from the Telegram Bot API * @param webhookReplyEnvelope An optional webhook reply envelope */ async handleUpdate( update: Update, webhookReplyEnvelope?: WebhookReplyEnvelope ) { if ( === undefined) throw new Error( 'Bot not initialized! Either call `await bot.init()`, \or directly set the `botInfo` option in the `Bot` constructor to specify \a known bot info object.' ) debug(`Processing update ${update.update_id}`) // create API object const api = new Api(this.token, this.clientConfig, webhookReplyEnvelope) // configure it with the same transformers as bot.api const t = this.api.config.installedTransformers() if (t.length > 0) api.config.use(...t) // create context object const ctx = new this.ContextConstructor(update, api, try { // run middleware stack await run(this.middleware(), ctx) } catch (err) { debugErr(`Error in middleware for update ${update.update_id}`) throw new BotError<C>(err, ctx) } }
/** * Starts your bot using long polling. * * This method effectively enters a loop that will repeatedly call * `getUpdates` and run your middleware for every received update, allowing * your bot to respond to messages. * * If your bot is already running, this method does nothing. * * This method returns a `Promise` that will never resolve except if your * bot is stopped. Remember to catch potential errors by calling * `bot.catch`, otherwise your bot will crash (and stop) if something goes * wrong in your code. * * **Note that this starts your bot using a very simple long polling * implementation.** `bot.start` should only be used for small bots. While * the rest of grammY was built to perform well even under extreme loads, * simple long polling is not capable of scaling up in a similar fashion. * You should switch over to using `@grammyjs/runner` if you are running a * bot with high load. * * What exactly _high load_ means differs from bot to bot, but as a rule of * thumb, simple long polling should not be processing more than ~5K * messages every hour. Also, if your bot has long-running operations such * as large file transfers that block the middleware from completing, this * will impact the responsiveness negatively, so it makes sense to use the * `@grammyjs/runner` package even if you receive much fewer messages. If * you worry about how much load your bot can handle, check out the grammY * [documentation]( about scaling * up. * * @param options Options to use for simple long polling */ async start(options?: PollingOptions) { // Perform setup await this.init() if (this.pollingRunning) { debug('Simple long polling already running!') return } await this.api.deleteWebhook({ drop_pending_updates: options?.drop_pending_updates, })
// Prevent common misuse that causes memory leak this.use = () => { throw new Error(`It looks like you are registering more listeners \on your bot from within other listeners! This means that every time your bot \handles a message like this one, new listeners will be added. This list grows until \your machine crashes, so grammY throws this error to tell you that you should \probably do things a bit differently. If you're unsure how to resolve this problem, \you can ask in the group chat:
On the other hand, if you actually know what you're doing and you do need to install \further middleware while your bot is running, consider installing a composer \instance on your bot, and in turn augment the composer after the fact. This way, \you can circumvent this protection against memory leaks.`) }
// Start polling debug('Starting simple long polling') this.pollingRunning = true this.pollingAbortController = new AbortController()
const limit = options?.limit const timeout = options?.timeout ?? 30 // seconds let allowed_updates = options?.allowed_updates try { options?.onStart?.(this.botInfo) } catch (error) { this.pollingRunning = false this.pollingAbortController = undefined throw error }
const handleErr = async (error: unknown) => { if (!this.pollingRunning) throw error else 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 (' ) throw error } else if (error.error_code === 409) { debugErr( 'Consider revoking the bot token if you believe that no other instance is running.' ) throw error } } else debugErr(error) debugErr('Call to `getUpdates` failed, retrying in 3 seconds ...') await new Promise(r => setTimeout(r, 3000)) }
while (this.pollingRunning) { // fetch updates const offset = this.lastTriedUpdateId + 1 let updates: Update[] | undefined = undefined do { try { updates = await this.api.getUpdates( { offset, limit, timeout, allowed_updates }, this.pollingAbortController.signal ) } catch (error) { await handleErr(error) } } while (updates === undefined && this.pollingRunning) if (updates === undefined) break // handle them sequentially (!) for (const update of updates) { this.lastTriedUpdateId = update.update_id try { await this.handleUpdate(update) } catch (err) { // should always be true if (err instanceof BotError) { await this.errorHandler(err) } else { console.error('FATAL: grammY unable to handle:', err) throw err } } } // Telegram uses the last setting if `allowed_updates` is omitted so // we can save same traffic by only sending it in the first request allowed_updates = undefined } debug('Middleware is done running') }
/** * Stops the bot from long polling. * * All middleware that is currently being executed may complete, but no * further `getUpdates` calls will be performed. The current `getUpdates` * request will be cancelled. * * In addition, this method will _confirm_ the last received update to the * Telegram servers by calling `getUpdates` one last time with the latest * offset value. If any updates are received in this call, they are * discarded and will be fetched again when the bot starts up the next time. * Confer the official documentation on confirming updates if you want to * know more: * * > Note that this method will not wait for the middleware stack to finish. * > If you need to run code after all middleware is done, consider waiting * > for the promise returned by `bot.start()` to resolve. */ async stop() { if (this.pollingRunning) { debug('Stopping bot, saving update offset') this.pollingRunning = false this.pollingAbortController?.abort() const offset = this.lastTriedUpdateId + 1 await this.api.getUpdates({ offset, limit: 1 }) this.pollingAbortController = undefined } else { debug('Bot is not running!') } }
/** * Sets the bots error handler that is used during long polling. * * You should call this method to set an error handler if you are using long * polling, no matter whether you use `bot.start` or the `@grammyjs/runner` * package to run your bot. * * Calling `bot.catch` when using other means of running your bot (or * webhooks) has no effect. * * @param errorHandler A function that handles potential middleware errors */ catch(errorHandler: ErrorHandler<C>) { this.errorHandler = errorHandler }}