fix: Don't invert redaction target helper

src/core/matrix/event/redact.rs

@@ -56,7 +56,12 @@ pub(super) fn is_redacted<E: Event>(event: &E) -> bool {
 		return false;
 	};
 
-	unsigned.redacted_because.is_some()
+	unsigned.redacted_by.is_some()
+}
+
+#[derive(Deserialize)]
+struct RedactionField {
+	redacts: OwnedEventId,
 }
 
 #[must_use]
@@ -69,16 +74,104 @@ pub(super) fn redacts_id<E: Event>(
 	}
 
 	if room_version_rules.redaction.content_field_redacts {
-		event.redacts().map(ToOwned::to_owned)
-	} else {
 		event
-			.get_content::<RoomRedactionEventContent>()
-			.ok()?
-			.redacts
+			.get_content::<RedactionField>()
+			.map(|r| r.redacts)
+			.ok()
+	} else {
+		event.redacts().map(ToOwned::to_owned)
 	}
 }
 
 #[derive(Deserialize)]
 struct ExtractRedactedBecause {
-	redacted_because: Option<serde::de::IgnoredAny>,
+	#[serde(rename = "org.continuwuity.redacted_by")]
+	redacted_by: Option<serde::de::IgnoredAny>,
+}
+
+#[cfg(test)]
+mod tests {
+	use ruma::{UInt, events::TimelineEventType, room_version_rules::RoomVersionRules};
+	use serde_json::json;
+
+	use crate::{Event, Pdu, pdu::EventHash};
+
+	#[test]
+	fn v11_redacts_from_content() {
+		let p = Pdu {
+			event_id: ruma::owned_event_id!("$v11"),
+			room_id: Some(ruma::owned_room_id!("!v11:example.com")),
+			sender: ruma::owned_user_id!("@user:example.com"),
+			origin: None,
+			origin_server_ts: UInt::default(),
+			kind: TimelineEventType::RoomRedaction,
+			content: serde_json::value::to_raw_value(&json!({"redacts": "$content_redacts"}))
+				.unwrap(),
+			sticky: None,
+			state_key: None,
+			prev_events: vec![],
+			depth: UInt::default(),
+			auth_events: vec![],
+			redacts: Some(ruma::owned_event_id!("$apex_redacts")),
+			unsigned: None,
+			hashes: EventHash { sha256: String::new() },
+			signatures: None,
+		};
+		assert_eq!(
+			p.redacts_id(&RoomVersionRules::V11),
+			Some(ruma::owned_event_id!("$content_redacts"))
+		);
+	}
+
+	#[test]
+	fn v10_redacts_from_apex() {
+		let p = Pdu {
+			event_id: ruma::owned_event_id!("$v11"),
+			room_id: Some(ruma::owned_room_id!("!v11:example.com")),
+			sender: ruma::owned_user_id!("@user:example.com"),
+			origin: None,
+			origin_server_ts: UInt::default(),
+			kind: TimelineEventType::RoomRedaction,
+			content: serde_json::value::to_raw_value(&json!({"redacts": "$content_redacts"}))
+				.unwrap(),
+			sticky: None,
+			state_key: None,
+			prev_events: vec![],
+			depth: UInt::default(),
+			auth_events: vec![],
+			redacts: Some(ruma::owned_event_id!("$apex_redacts")),
+			unsigned: None,
+			hashes: EventHash { sha256: String::new() },
+			signatures: None,
+		};
+		assert_eq!(
+			p.redacts_id(&RoomVersionRules::V10),
+			Some(ruma::owned_event_id!("$apex_redacts"))
+		);
+	}
+
+	#[test]
+	fn redacts_ignores_non_redaction_event() {
+		let p = Pdu {
+			event_id: ruma::owned_event_id!("$v11"),
+			room_id: Some(ruma::owned_room_id!("!v11:example.com")),
+			sender: ruma::owned_user_id!("@user:example.com"),
+			origin: None,
+			origin_server_ts: UInt::default(),
+			kind: TimelineEventType::RoomMessage,
+			content: serde_json::value::to_raw_value(&json!({"redacts": "$content_redacts"}))
+				.unwrap(),
+			sticky: None,
+			state_key: None,
+			prev_events: vec![],
+			depth: UInt::default(),
+			auth_events: vec![],
+			redacts: Some(ruma::owned_event_id!("$apex_redacts")),
+			unsigned: None,
+			hashes: EventHash { sha256: String::new() },
+			signatures: None,
+		};
+		assert_eq!(p.redacts_id(&RoomVersionRules::V11), None);
+		assert_eq!(p.redacts_id(&RoomVersionRules::V10), None);
+	}
 }