move or_empty deserializer to ruma-common, add tests

Signed-off-by: morguldir <morguldir@protonmail.com>

crates/ruma-client-api/src/keys/upload_signing_keys.rs

@@ -26,27 +26,13 @@ pub mod v3 {
             1.1 => "/_matrix/client/v3/keys/device_signing/upload",
         }
     };
-
-    fn or_empty<'de, D: serde::Deserializer<'de>, T: serde::Deserialize<'de>>(
-        deserializer: D,
-    ) -> Result<Option<T>, D::Error> {
-        #[derive(serde::Deserialize)]
-        #[serde(untagged)]
-        enum OrEmpty<T> {
-            NotEmpty(T),
-            Empty {},
-        }
-        let res = <Option<OrEmpty<T>> as serde::Deserialize<'de>>::deserialize(deserializer)?;
-        Ok(res.and_then(|res| if let OrEmpty::NotEmpty(a) = res { Some(a) } else { None }))
-    }
-
     /// Request type for the `upload_signing_keys` endpoint.
     #[request(error = UiaaResponse)]
     #[derive(Default)]
     pub struct Request {
         /// Additional authentication information for the user-interactive authentication API.
         #[serde(skip_serializing_if = "Option::is_none")]
-        #[serde(deserialize_with = "or_empty")]
+        #[serde(deserialize_with = "ruma_common::serde::or_empty")]
         #[serde(default)]
         pub auth: Option<AuthData>,
 

crates/ruma-client-api/src/uiaa.rs

@@ -729,3 +729,38 @@ impl OutgoingResponse for UiaaResponse {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use assert_matches2::assert_matches;
+    use serde;
+
+    #[test]
+    fn test_empty_uiaa_serialization() {
+        let input = "{}";
+        let result = serde_json::from_str::<super::AuthData>(input);
+        assert!(result.is_err());
+    }
+
+    #[derive(Debug, Default, serde::Serialize, serde::Deserialize)]
+    #[serde()]
+    struct Request {
+        /// Additional authentication information for the user-interactive authentication API.
+        #[serde(deserialize_with = "ruma_common::serde::or_empty")]
+        pub auth: Option<super::AuthData>,
+    }
+
+    #[test]
+    fn test_option_uiaa_serialization() {
+        let input = r#"{"auth": {}}"#;
+        let result = serde_json::from_str::<Request>(input).unwrap();
+        assert_matches!(result.auth, None);
+    }
+
+    #[test]
+    fn test_fail_uiaa_serialization() {
+        let input = r#"{"auth": "aaw"}"#;
+        let result = serde_json::from_str::<Request>(input);
+        assert!(result.is_err());
+    }
+}

crates/ruma-common/src/serde.rs

@@ -69,6 +69,19 @@ pub fn is_true(b: &bool) -> bool {
     *b
 }
 
+/// Returns None if the serialization fails
+pub fn or_empty<'de, D: Deserializer<'de>, T: Deserialize<'de>>(
+        deserializer: D,
+    ) -> Result<Option<T>, D::Error> {
+        #[derive(serde::Deserialize)]
+        #[serde(untagged)]
+        enum OrEmpty<T> {
+            NotEmpty(T),
+            Empty {},
+        }
+        let res = <Option<OrEmpty<T>> as Deserialize<'de>>::deserialize(deserializer)?;
+        Ok(res.and_then(|res| if let OrEmpty::NotEmpty(a) = res { Some(a) } else { None }))
+    }
 /// Helper function for `serde_json::value::RawValue` deserialization.
 #[inline(never)]
 pub fn from_raw_json_value<'a, T, E>(val: &'a RawJsonValue) -> Result<T, E>