Added go-fuzz for parser

[tie]

It’d be nice to integrate continuous fuzzing too, but I’m not aware of any easy to set up (and free) services.

See also #252

[codecov-io]

Codecov Report

Merging #253 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #253   +/-   ##
=======================================
  Coverage   61.35%   61.35%           
=======================================
  Files          68       68           
  Lines        6345     6345           
=======================================
  Hits         3893     3893           
  Misses       1936     1936           
  Partials      516      516           

Impacted Files	Coverage Δ
database/config.go	68.59% <0.00%> (ø)
sql/query/reindex.go	81.81% <0.00%> (ø)

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[asdine]

Could we run the fuzzer on a Github Action when a branch is merged on master for example?

[tie]

Yes, we can do that. I think it’s better to run a scheduled nightly fuzz test.

I’ll write a workflow that stores corpus in cache, but we’d probably need a separate repo or some kind of file storage for corpus data if we don’t want to lose it.

[asdine]

@tie Is this something that must be generated once and stored somewhere? If so, how about storing it in the Genji repo directly?

[tie]

For each Fuzz function we need corpus data. Ideally, we should also update it since running go-fuzz may find new inputs that increase coverage (we can git push from GitHub Actions workflow with zero setup).

See libFuzzerTutorial.md#Continuous fuzzing.

[asdine]

@tie I have created a repo for storing the corpus data: https://github.com/genjidb/go-fuzz-corpus

[asdine]

@tie Is it ready for review?

[tie]

@asdine yes!

There would be another PR to go-fuzz-corpus repo with actions workflow to update the corpus on nightly schedule but the changes for main repo are ready.

Note that the (1.15.x, windows, genji/engine/badgerengine) combo fails with -race flag (see the latest workflow run on the PR source branch). Should we (temporarily) exclude it from the matrix?

[tie]

I’ve removed go test workflows since they are still work-in-progress. I’ll submit them as a new PR, and will also add tinygo test runner (currently we only run tests with tinygo tag in Travis config).

[asdine]

Thanks @tie ! That's great job! Let's iterate on this for tinygo and race on subsequent PRs 👍🏼

[tie]

Neat, it’s working. Found another bug too!