Perl 6's test suite, called Roast, can be found in the repository at https://github.com/perl6/roast. It contains thousands of tests covering many corners of Perl 6. The test suite is also a good place to look if you want to see ways you can write programs in Perl 6. It may be a long read sometimes, but many tests are checking the features from all possible angles.
In Roast, the tests are grouped in directories with names such as S32-io. These names correspond to the numbers of the Synopses, and are split into thematic sections. For example, for the Synopses 11 'Compilation Units', there exist three directories in tests—S11-compunits, S11-modules, and S11-repository.