For reasons, I've become interested in the background to the term "edge case". I'd presumed it was old school engineering terminology that had been ported over to software.<p>But searching on Google Books etc. all the uses that fit the modern meaning are related to programming/software testing, and even those examples are relatively recent.<p>Is this correct or am I missing something?
<a href="https://books.google.com/ngrams/graph?content=corner+case%2C+edge+case&year_start=1800&year_end=2019&corpus=en-2019&smoothing=3" rel="nofollow">https://books.google.com/ngrams/graph?content=corner+case%2C...</a><p>suggests it's a low-dimension version of "corner case", which I believe comes from aerospace*. (both spike in 1947-1957, which, albeit possible, seems early for a software origin)<p>* compare "coffin corner": <a href="https://books.google.com/ngrams/graph?content=corner+case%2Cedge+case%2C+coffin+corner&year_start=1800&year_end=2019&corpus=en-2019&smoothing=3" rel="nofollow">https://books.google.com/ngrams/graph?content=corner+case%2C...</a>
Apparently it started out in aviation engineering, referring to unusual behavior at the edge of the flight envelope. Related to 'corner case'.