Allow comparing UserIds and ChatIds

crates/teloxide-core/CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `VideoChatEnded::duration` field that was previously missed ([#859][pr859])
 - `ThreadId` newtype over `MessageId`, used for identifying reply threads ([#887][pr887])
 - `ChatId::as_user` ([#905][pr905])
+- Implement `PartialEq<ChatId> for UserId` and `PartialEq<UserId> for ChatId` ([#905][pr905])
 
 [pr851]: https://github.com/teloxide/teloxide/pull/851
 [pr887]: https://github.com/teloxide/teloxide/pull/887

crates/teloxide-core/src/types/chat_id.rs

@@ -82,6 +82,12 @@ impl From<UserId> for ChatId {
     }
 }
 
+impl PartialEq<UserId> for ChatId {
+    fn eq(&self, other: &UserId) -> bool {
+        self.is_user() && *self == ChatId::from(*other)
+    }
+}
+
 impl BareChatId {
     /// Converts bare chat id back to normal bot API [`ChatId`].
     #[allow(unused)]
@@ -152,4 +158,16 @@ mod tests {
     fn display() {
         assert_eq!(ChatId(1).to_string(), "1");
     }
+
+    #[test]
+    fn user_id_eq() {
+        assert_eq!(ChatId(12), UserId(12));
+        assert_eq!(ChatId(4652762), UserId(4652762));
+        assert_ne!(ChatId(17), UserId(42));
+
+        // The user id is not well formed, so even though `-1 == max` is true,
+        // we don't want user id to match
+        assert_eq!(-1i64, u64::MAX as i64);
+        assert_ne!(ChatId(-1), UserId(u64::MAX));
+    }
 }

crates/teloxide-core/src/types/user_id.rs

@@ -1,5 +1,7 @@
 use serde::{Deserialize, Serialize};
 
+use crate::types::ChatId;
+
 /// Identifier of a user.
 #[derive(Clone, Copy)]
 #[derive(Debug, derive_more::Display)]
@@ -52,6 +54,13 @@ impl UserId {
     }
 }
 
+impl PartialEq<ChatId> for UserId {
+    fn eq(&self, other: &ChatId) -> bool {
+        // Reuse `PartialEq<UserId> for ChatId` impl
+        other == self
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use serde::{Deserialize, Serialize};