Summary

Updates to #10193 - made it a separate pr into master because I have merged a lot of changes from master.

Updates

Improvements:

• Merge master; use latest solar v0.1.8
• Full mutation de/serialization for caching
• Cache mutants/results per-build-id and per-file
• Tries to identify which Spans already have surviving mutants and skips running tests on Mutants of duplicate or sub-Spans

Things to check/explicitly test

• Updates to src invalidates both mutant and results cache
• Updates to test suite invalidates only results cache

Proposed "v0" todos:

• At least parity with high-level gambit mutators
  • Basic Yul/inline-assembly mutators
• Mutate in a tmp dir, not src
• Use type information (possibly as part of hir) for fewer invalid mutations
• More informative summaries
  • Report type of mutation being run
  • Breakdown of mutation counts by type
• Report diffs of surviving mutants, similar to Gambit
  • ability to save mutation report to a file, e.g., .mutations-snapshot
• Add ability to generate + profile mutants independently from running test suite
• Cache per-file incremental results so mutation tests may be interrupted + resumed if build-id/hash stays the same (currently per-contract)
• Automatically delete old mutant caches if build-id/hash changes
• Assess new unit test framework
• Complete integration tests

Proposed "v1" todos:

• lcov support for coverage gutters
• true multithreaded - probably using stdin to solc
• gzip mutants + results?
• Explore ordering of mutators and proposed mutants to increase likelihood of skipping redundant mutations
  • This is probably complicated by mutli-threading