From 74e32a725da8067b6daca88451023c0cab5c1961 Mon Sep 17 00:00:00 2001
From: Maybe Waffle <waffle.lapkin@gmail.com>
Date: Mon, 6 Feb 2023 12:17:55 +0400
Subject: [PATCH] Add tests for response processing

---
 crates/teloxide-core/src/errors.rs      |   1 +
 crates/teloxide-core/src/net/request.rs | 120 ++++++++++++++++++++++++
 2 files changed, 121 insertions(+)

diff --git a/crates/teloxide-core/src/errors.rs b/crates/teloxide-core/src/errors.rs
index 41acffdf..45be0f70 100644
--- a/crates/teloxide-core/src/errors.rs
+++ b/crates/teloxide-core/src/errors.rs
@@ -17,6 +17,7 @@ pub enum RequestError {
     /// The group has been migrated to a supergroup with the specified
     /// identifier.
     #[error("The group has been migrated to a supergroup with ID #{0}")]
+    // FIXME: change to `ChatId` :|
     MigrateToChatId(i64),
 
     /// In case of exceeding flood control, the number of seconds left to wait
diff --git a/crates/teloxide-core/src/net/request.rs b/crates/teloxide-core/src/net/request.rs
index 6c0580fe..b990e588 100644
--- a/crates/teloxide-core/src/net/request.rs
+++ b/crates/teloxide-core/src/net/request.rs
@@ -99,6 +99,13 @@ where
 
     let text = response.text().await?;
 
+    deserialize_response(text)
+}
+
+fn deserialize_response<T>(text: String) -> Result<T, RequestError>
+where
+    T: DeserializeOwned + 'static,
+{
     serde_json::from_str::<TelegramResponse<T>>(&text)
         .map(|mut response| {
             use crate::types::{Update, UpdateKind};
@@ -152,3 +159,116 @@ where
         .map_err(|source| RequestError::InvalidJson { source, raw: text.into() })?
         .into()
 }
+
+#[cfg(test)]
+mod tests {
+    use std::time::Duration;
+
+    use cool_asserts::assert_matches;
+
+    use crate::{
+        net::request::deserialize_response,
+        types::{True, Update, UpdateKind},
+        ApiError, RequestError,
+    };
+
+    #[test]
+    fn smoke_ok() {
+        let json = r#"{"ok":true,"result":true}"#.to_owned();
+
+        let res = deserialize_response::<True>(json);
+        assert_matches!(res, Ok(True));
+    }
+
+    #[test]
+    fn smoke_err() {
+        let json =
+            r#"{"ok":false,"description":"Forbidden: bot was blocked by the user"}"#.to_owned();
+
+        let res = deserialize_response::<True>(json);
+        assert_matches!(res, Err(RequestError::Api(ApiError::BotBlocked)));
+    }
+
+    #[test]
+    fn migrate() {
+        let json = r#"{"ok":false,"description":"this string is ignored","parameters":{"migrate_to_chat_id":123456}}"#.to_owned();
+
+        let res = deserialize_response::<True>(json);
+        assert_matches!(res, Err(RequestError::MigrateToChatId(123456)));
+    }
+
+    #[test]
+    fn retry_after() {
+        let json = r#"{"ok":false,"description":"this string is ignored","parameters":{"retry_after":123456}}"#.to_owned();
+
+        let res = deserialize_response::<True>(json);
+        assert_matches!(res, Err(RequestError::RetryAfter(duration)) if duration == Duration::from_secs(123456));
+    }
+
+    #[test]
+    fn update_ok() {
+        let json = r#"{
+            "ok":true,
+            "result":[
+                {
+                    "update_id":0,
+                    "poll_answer":{
+                        "poll_id":"POLL_ID",
+                        "user": {"id":42,"is_bot":false,"first_name":"blah"},
+                        "option_ids": []
+                    }
+                }
+            ]
+        }"#
+        .to_owned();
+
+        let res = deserialize_response::<Vec<Update>>(json).unwrap();
+        assert_matches!(res, [Update { id: 0, kind: UpdateKind::PollAnswer(_) }]);
+    }
+
+    /// Check that `get_updates` can work with malformed updates.
+    #[test]
+    fn update_err() {
+        let json = r#"{
+            "ok":true,
+            "result":[
+                {
+                    "update_id":0,
+                    "poll_answer":{
+                        "poll_id":"POLL_ID",
+                        "user": {"id":42,"is_bot":false,"first_name":"blah"},
+                        "option_ids": []
+                    }
+                },
+                {
+                    "update_id":1,
+                    "something unknown to us":17
+                },
+                {
+                    "update_id":2,
+                    "poll_answer":{
+                        "poll_id":"POLL_ID",
+                        "user": {"id":42,"is_bot":false,"first_name":"blah"},
+                        "option_ids": [3, 4, 8]
+                    }
+                },
+                {
+                    "update_id":3,
+                    "message":{"some fields are missing":true}
+                }
+            ]
+        }"#
+        .to_owned();
+
+        let res = deserialize_response::<Vec<Update>>(json).unwrap();
+        assert_matches!(
+            res,
+            [
+                Update { id: 0, kind: UpdateKind::PollAnswer(_) },
+                Update { id: 1, kind: UpdateKind::Error(v) } if v.is_object(),
+                Update { id: 2, kind: UpdateKind::PollAnswer(_) },
+                Update { id: 3, kind: UpdateKind::Error(v) } if v.is_object(),
+            ]
+        );
+    }
+}