codePreviews: add react to delete

src/modules/codePreviews.js

@@ -144,3 +144,40 @@ events.add("messageCreate", "codePreviews", async function (msg) {
     }
   }
 });
+
+// TODO: maybe all command outputs should have this ability
+events.add(
+  "messageReactionAdd",
+  "codePreviews",
+  async function (msg, reaction, reactor) {
+    if (!msg.guildID) return;
+    if (!(await hasFlag(msg.guildID, "codePreviews"))) return;
+    if (reaction.name != "\u274c") return;
+
+    let channel = msg.channel;
+    if (!channel.name) {
+      channel = hf.bot.getChannel(channel.id);
+    }
+    if (!msg.messageReference) {
+      msg = await channel.getMessage(msg.id);
+    }
+
+    if (!msg.messageReference) return;
+
+    const ref = await channel.getMessage(msg.messageReference.messageID);
+    if (!ref) return;
+    if (
+      ref.author.id != reactor.id ||
+      !channel.permissionsOf(reactor.id).has("manageMessages")
+    )
+      return;
+    if (
+      !REGEX_GITHUB.test(ref.content) &&
+      !REGEX_GITLAB.test(ref.content) &&
+      !REGEX_GITEA.test(ref.content)
+    )
+      return;
+
+    await msg.delete("Author requested code preview deletion");
+  }
+);