"metatap is a simple testing tool for TAP producers. It reads TAP from standard input, along with the expected results on the command line. It then produces (and optionally runs) TAP describing how the input TAP was interpreted by TAP::Harness."
If you are building tap4j from source you can execute the tests by running mvn -e clean test -Pperl-integration. This command executes a TestNG 6.0 class that creates a TapProducer, dumps its contents to a temporary file and then reads it with metatap.
This test requires having "perl" in PATH, and was created in Windows running Strawberry Perl. So there may have issues running it in different operational systems.
We are happy to announce that tap4j passed in all integration tests :)