We've been developed protoxform for the vN -> V(N+1)alpha transform described in #8399. So far, we've manually inspected diffs against v2 and previous runs of protoxform to confirm that behavior is correct. This makes sense while we prototype and define the intended behaviors of the tool. Longer term (post 1.12.0), we will want some tests though.

This task tracks creating some tests for protoxform. I think some "golden proto" style tests make the most sense, i.e. example inputs/outputs and proto diffing for correctness. A good example of a similar tool with solid testing is https://github.com/envoyproxy/protoc-gen-validate.