go-fuzz
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dvyukov
Packages missing from the coverage
I started writing fuzzy tests for go-ipfs but I've hit quite a big wall.
The instrumentation during build process is not performed if any package if dependency tree of given package has import "C". This causes about 80% of our code to not be instrumented by go-fuzz, which means that it doesn't really try to cover our code.
Whole problem seems to be down to net package and runtime/cgo packages which do import "C".
OK, running with CGO_ENABLED=0 seems to resolve it.
Is that the official way of doing it? If yes then it would be good to recommend it by default as net dependency is quite common an it screws the coverage completely.
CGO_ENABLED=0 is the best solution for now.
Ultimately go-fuzz is integrated into Go compiler and build system, which would eliminate all these constant breakages related to cgo, vendoring, internal packages, new package naming restrictions, etc.
@dvyukov Is there any bug open to track the steps required for this to be integrated upstream?
@dgryski No, there is none. Feel free to file a one. Ideally Fuzz functions can be defined in test packages along with unit tests and benchmarks and then easily executed either in continuous coverage-guided mode, or in unit testing mode (corpus is executed once and/or a fixed number of additional random inputs). Maybe it should be integrated with testing/quick package, or maybe not.