Epistemic Status: 
Sprouting - This is a zettelkasten-style card about a concept I’m interested in remembering.
Metamorphic testing is a testing technique that expands on property-based testing by testing properties spanning multiple inputs and outputs called a metamorphic relation.
- Metamorphic Testing — the blog post that introduced me to this idea.
- Metamorphic Testing of RESTful Web APIs — a paper about doing this sort of testing and uncovering bugs on the Spotify and YouTube APIs.