From b50037affc4039285ad80856f30e20b9239557b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Commaille?= <zecakeh@tedomum.fr>
Date: Thu, 27 Apr 2023 18:53:42 +0200
Subject: [PATCH] events: Implement sanitize on MessageType

---
 crates/ruma-common/CHANGELOG.md               |  1 +
 crates/ruma-common/src/events/room/message.rs | 52 ++++++++++++++-----
 2 files changed, 40 insertions(+), 13 deletions(-)

diff --git a/crates/ruma-common/CHANGELOG.md b/crates/ruma-common/CHANGELOG.md
index 002ef3b6..392a0e00 100644
--- a/crates/ruma-common/CHANGELOG.md
+++ b/crates/ruma-common/CHANGELOG.md
@@ -31,6 +31,7 @@ Improvements:
   - `user_can_send_message`
   - `user_can_send_state`
   - `user_can_trigger_room_notification`
+- Add `MessageType::sanitize` behind the `unstable-sanitize` feature
 
 # 0.11.3
 
diff --git a/crates/ruma-common/src/events/room/message.rs b/crates/ruma-common/src/events/room/message.rs
index 64d09994..26bb8293 100644
--- a/crates/ruma-common/src/events/room/message.rs
+++ b/crates/ruma-common/src/events/room/message.rs
@@ -326,19 +326,13 @@ impl RoomMessageEventContent {
         mode: HtmlSanitizerMode,
         remove_reply_fallback: RemoveReplyFallback,
     ) {
-        if let MessageType::Emote(EmoteMessageEventContent { body, formatted, .. })
-        | MessageType::Notice(NoticeMessageEventContent { body, formatted, .. })
-        | MessageType::Text(TextMessageEventContent { body, formatted, .. }) = &mut self.msgtype
-        {
-            if let Some(formatted) = formatted {
-                formatted.sanitize_html(mode, remove_reply_fallback);
-            }
-            if remove_reply_fallback == RemoveReplyFallback::Yes
-                && matches!(self.relates_to, Some(Relation::Reply { .. }))
-            {
-                *body = remove_plain_reply_fallback(body).to_owned();
-            }
-        }
+        let remove_reply_fallback = if matches!(self.relates_to, Some(Relation::Reply { .. })) {
+            remove_reply_fallback
+        } else {
+            RemoveReplyFallback::No
+        };
+
+        self.msgtype.sanitize(mode, remove_reply_fallback);
     }
 }
 
@@ -558,6 +552,38 @@ impl MessageType {
             Self::_Custom(c) => Cow::Borrowed(&c.data),
         }
     }
+
+    /// Sanitize this message.
+    ///
+    /// If this message contains HTML, this removes the [tags and attributes] that are not listed in
+    /// the Matrix specification.
+    ///
+    /// It can also optionally remove the [rich reply fallback] from the plain text and HTML
+    /// message. Note that you should be sure that the message is a reply, as there is no way to
+    /// differentiate plain text reply fallbacks and markdown quotes.
+    ///
+    /// This method is only effective on text, notice and emote messages.
+    ///
+    /// [tags and attributes]: https://spec.matrix.org/latest/client-server-api/#mroommessage-msgtypes
+    /// [rich reply fallback]: https://spec.matrix.org/latest/client-server-api/#fallbacks-for-rich-replies
+    #[cfg(feature = "unstable-sanitize")]
+    pub fn sanitize(
+        &mut self,
+        mode: HtmlSanitizerMode,
+        remove_reply_fallback: RemoveReplyFallback,
+    ) {
+        if let MessageType::Emote(EmoteMessageEventContent { body, formatted, .. })
+        | MessageType::Notice(NoticeMessageEventContent { body, formatted, .. })
+        | MessageType::Text(TextMessageEventContent { body, formatted, .. }) = self
+        {
+            if let Some(formatted) = formatted {
+                formatted.sanitize_html(mode, remove_reply_fallback);
+            }
+            if remove_reply_fallback == RemoveReplyFallback::Yes {
+                *body = remove_plain_reply_fallback(body).to_owned();
+            }
+        }
+    }
 }
 
 impl From<MessageType> for RoomMessageEventContent {