bridge both ways and prevent reflections

m2d/converters/utils.js

@@ -0,0 +1,21 @@
+// @ts-check
+
+const reg = require("../../matrix/read-registration")
+const userRegex = reg.namespaces.users.map(u => new RegExp(u.regex))
+/**
+ * Determine whether an event is the bridged representation of a discord message.
+ * Such messages shouldn't be bridged again.
+ * @param {string} sender
+ */
+function eventSenderIsFromDiscord(sender) {
+	// If it's from a user in the bridge's namespace, then it originated from discord
+	// This includes messages sent by the appservice's bot user, because that is what's used for webhooks
+	// TODO: It would be nice if bridge system messages wouldn't trigger this check and could be bridged from matrix to discord, while webhook reflections would remain ignored...
+	if (userRegex.some(x => sender.match(x))) {
+		return true
+	}
+
+	return false
+}
+
+module.exports.eventSenderIsFromDiscord = eventSenderIsFromDiscord