perl-testing

Use Test2::V0 with is() for equality, hash and array builders for deep comparison, and subtest blocks to group related assertions. Always end the file with done_testing to verify all planned tests executed.

Test2::V0 is the modern replacement for Test::More, offering richer deep-comparison builders, better failure diagnostics, and cleaner subtest scoping. It remains backward-compatible with Test::More tests, so migration can be incremental.

Run prove -lr t/ to execute all tests recursively with lib/ in @INC. Add -v for verbose output, -j8 for parallel execution, or --state=failed to rerun only previously failing tests.

Use Test::MockModule to override methods on a target package; the mock restores automatically when the object goes out of scope. For lightweight test doubles, use Test::MockObject and verify calls with called_ok.

This happens when prove runs without the -l flag, so modules in lib/ are not in @INC. Run prove -l t/ or add -l to a .proverc file to include the lib directory permanently.

Run cover -test to execute the suite under Devel::Cover and generate a summary, then cover -report html for a browsable report. In CI, parse the text report and fail the build when total coverage drops below your threshold.