https://approvaltests.com/
https://github.com/approvals

https://github.com/approvals/ApprovalTests.cpp
https://github.com/approvals/ApprovalTests.cpp/blob/master/doc/Overview.md
https://github.com/approvals/ApprovalTests.cpp/blob/master/doc/Tutorial.md

2019
Macrae - Quickly Testing Legacy C++ Code with Approval Tests
    https://www.youtube.com/watch?v=3GZHvcdq32s