tests.expected and tests.in are sourced from FUSE, the For UNIX Spectrum Emulator. FUSE is GPL software, and can be found at:

https://sourceforge.net/projects/fuse-emulator/

tests.exepected.json and tests.in.json are direct derivatives of those files and therefore are also offered under the GPL. See the converters directory for the hacky means I used to generate those from the originals.