References
- [https://github.com/matrix-org/matrix-appservice-irc/pull/1465/files](https://github.com/matrix-org/matrix-appservice-irc/pull/1465/files)
- [https://github.com/matrix-org/matrix-appservice-irc/blob/develop/src/util/MessageDiff.ts](https://github.com/matrix-org/matrix-appservice-irc/blob/develop/src/util/MessageDiff.ts)
- [https://github.com/matrix-org/matrix-appservice-irc/blob/develop/spec/unit/MessageDiff.spec.js](https://github.com/matrix-org/matrix-appservice-irc/blob/develop/spec/unit/MessageDiff.spec.js)