fuzztesting

[Tsche]

rsl::test should support fuzz tests.

minimal example:

extern "C" size_t
LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize);

extern "C" size_t LLVMFuzzerCustomMutator(uint8_t *Data, size_t Size,
                                          size_t MaxSize, unsigned int Seed) {
  // do custom mutations?
  return LLVMFuzzerMutate(Data, Size, MaxSize);
}

extern "C" int LLVMFuzzerRunDriver(int *argc, char ***argv,
                  int (*UserCb)(const uint8_t *Data, size_t Size));

int main(int argc, char** argv) {
  // fake argc/argv to set proper options
  LLVMFuzzerRunDriver(&argc, &argv, &test);
}

use google's fuzztest as reference. Centipede support is not desired at this point, libfuzzer is enough

[Tsche]

[[=test]]
[[=fuzz]] // this is a fuzz test, fixture insertion is not attempted
void foo(int x) { /* ... */ } 

[[=test]]
[[=fuzz]] // this is a fuzz test, fixture insertion is only done for the first parameter
void foo([[=fixture]] int x, int y) { /* ... */ }

[[=test]]
[[=fuzz]] // this is a fuzz test
[[=params{{1, 'c'}, {4, 'd'}}]] // this is also a unit test with 2 parameterizations, disables fixtures
void foo(int a, char b) { /* ... */ }  // fixtures not supported

[[=test]]
[[=fuzz]] // this is a fuzz test, domains are used for custom mutators
void foo([[=NonZero]] int a) { /* ... */ }

[Tsche]

Reflecting function parameter annotations outside of that function is currently not supported. One possible workaround is to accept a tagged wrapper type instead, so ie [[=NonZero]] int becomes NonZero<int>