Added testing field to README

README.md

@@ -286,6 +286,61 @@ async fn receive_location(
 
 [More examples >>](crates/teloxide/examples/)
 
+## Testing
+
+A crate [`teloxide_tests`](https://github.com/LasterAlex/teloxide_tests) can be used to test your bots.
+
+An example of its usage:
+
+```rust,ignore
+use teloxide::{
+    dispatching::{dialogue::GetChatId, UpdateHandler},
+    prelude::*,
+};
+
+fn handler_tree() -> UpdateHandler<Box<dyn std::error::Error + Send + Sync + 'static>> {
+    dptree::entry().endpoint(|update: Update, bot: Bot| async move {
+        bot.send_message(update.chat_id().unwrap(), "Hello World!")
+            .await?;
+        Ok(())
+    })
+}
+
+#[tokio::main]
+async fn main() {
+    let bot = Bot::from_env();
+
+    Dispatcher::builder(bot, handler_tree())
+        .enable_ctrlc_handler()
+        .build()
+        .dispatch()
+        .await;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use teloxide_tests::{MockBot, MockMessageText};
+
+    #[tokio::test]
+    async fn test_hello_world() {
+        let message = MockMessageText::new().text("Hi!");
+        let bot = MockBot::new(message, handler_tree());
+        // Sends the message as if it was from a user
+        bot.dispatch().await;  
+
+        let responses = bot.get_responses();
+        let message = responses
+            .sent_messages
+            .last()
+            .expect("No sent messages were detected!");
+        assert_eq!(message.text(), Some("Hello World!"));
+    }
+}
+```
+
+[More testing examples >>](https://github.com/LasterAlex/teloxide_tests/tree/master/examples)
+
 ## Tutorials
 
  - [_"Migrating my family finance bot from Python to Rust (teloxide) because I am tired of exceptions (part 1)"_](https://trkohler.com/posts/i-migrated-my-family-finance-bot-from-python-to-rust-because-i-am-tired-of-exceptions/) by Troy Köhler.