FuzzTesting

This subpackage build binaries to be use with Fuzz testing.

NOTE: The Swift toolchain distributed with Xcode do not include the fuzzing support, so for macOS, one needs to install the swift.org toolchain and use that instead.

To build on macOS:

xcrun \
  --toolchain swift \
  swift build -c debug -Xswiftc -sanitize=fuzzer,address -Xswiftc -parse-as-library

To build on linux:

swift build -c debug -Xswiftc -sanitize=fuzzer,address -Xswiftc -parse-as-library

Then the binaries will be found in .build/debug.

Note: You can also use -c release to build/test in release instead as that could find different issues.

In this directory you will also find a do_build.sh script. By default it builds for both debug and release. You can also pass --run-regressions to have it run the the build against the previous failcases to check for regressions.

When issues are found:

1. Make sure you add a file to FailCases subdirectory so regressions can easily be watched for.

2. Consider adding them to the unit tests as well. This can provide even better regression testing.

This infrastructure was originally developed for Swift Protobuf, and has been adapted for SwiftNIO HTTP/2.