Add padding for responses in comments, to let threads appear

Fixes #144

plume-models/src/comments.rs

@@ -69,13 +69,17 @@ impl Comment {
             .len()
     }
 
-    pub fn to_json(&self, conn: &PgConnection) -> serde_json::Value {
+    pub fn to_json(&self, conn: &PgConnection, others: &Vec<Comment>) -> serde_json::Value {
         let mut json = serde_json::to_value(self).unwrap();
         json["author"] = self.get_author(conn).to_json(conn);
         let mentions = Mention::list_for_comment(conn, self.id).into_iter()
             .map(|m| m.get_mentioned(conn).map(|u| u.get_fqn(conn)).unwrap_or(String::new()))
             .collect::<Vec<String>>();
         json["mentions"] = serde_json::to_value(mentions).unwrap();
+        json["responses"] = json!(others.into_iter()
+            .filter(|c| c.in_response_to_id.map(|id| id == self.id).unwrap_or(false))
+            .map(|c| c.to_json(conn, others))
+            .collect::<Vec<_>>());
         json
     }