Changes for version 0.42 - 2026-07-07
- New features
- Add CoverageGuidedFuzzer->minimize_corpus(): reduces the accumulated fuzz corpus to the minimum subset that still covers every branch discovered in the current run, using a greedy set-cover algorithm. Entries without branch data (loaded from a previous run or kept by random sampling when Devel::Cover is unavailable) are deduplicated by canonical JSON fingerprint. Bug-triggering inputs are always retained regardless of coverage contribution. Returns a hashref with keys before, after, and branches.
- Add --minimize-corpus flag to bin/extract-schemas: calls minimize_corpus() between run() and save_corpus() so corpus files stay bounded in size across repeated CI runs.
- Add POD example round-trip testing: new module App::Test::Generator::PodExampleExtractor extracts runnable code examples from =head1 SYNOPSIS, =head2 SYNOPSIS, and =for example begin/end blocks, plus annotated inline examples of the form "# returns value" or "# => value". New script bin/pod-example-tester generates a Test::Most-based .t file from any .pm file; each subtest wraps the example in eval{}, asserts it does not die, and (for annotated examples) compares the return value with is(). SchemaExtractor::_extract_pod_examples now also accepts =head1 SYNOPSIS (previously only =head2) and collects =for example blocks.
- Add GitHub Actions workflow deployment: new script bin/deploy-workflows copies dashboard.yml and mutate.yml (both embedded verbatim in the script via Data::Section::Simple __DATA__ sections) into the target repository's .github/workflows/ directory. Supports --target DIR, --force (overwrite existing files), --dry-run (preview without writing), --version, and --help. Prints git add/commit/push next-step instructions on success. The embedded workflow files are identical to the master copies in .github/workflows/ and work without any sibling files, maintaining the portability guarantee introduced in 0.41.
- Add automatic benchmark generation: new module App::Test::Generator::BenchmarkGenerator and new script bin/benchmark-generator produce self-contained Perl benchmark scripts (using Benchmark::cmpthese) from any ATG YAML schema. Each transform defined in the schema becomes a named cmpthese variant; representative input values are derived from each parameter's type and range constraints (min/max midpoint, or type defaults). OOP schemas (those with a new: key) emit a constructor call before the benchmark loop.
- Add CPAN Testers reproduction harness to bin/test-generator-index: for each FAIL report where installed-module data is available, a self-contained shell script (cover_html/reproduce/reproduce-GUID.sh) is generated that pins every installed module version with cpanm and suggests the matching Perl via perlbrew/plenv, allowing any developer to reproduce the exact failing environment locally. Scripts are linked as downloadable "Script" links in the CPAN Testers failure table on the dashboard.
- Bug fixes
- Fix SchemaExtractor::_compile_signature_isolated to degrade gracefully when the isolated subprocess fails. Previously a subprocess error (stderr) triggered an unconditional croak, propagating a fatal exception through _extract_type_params_schema's "or return" guard (which catches falsy returns but not exceptions). The croak now becomes a verbose-gated carp followed by a plain return so the caller falls back to heuristic analysis as intended. A secondary guard in the subprocess heredoc now checks that the return value of signature_for() is a blessed object with a parameters() method before calling it, so older Type::Params (< 2.x) installations — which install the constraint but return undef rather than the signature object — no longer cause the subprocess to die and write to stderr. Reported via CPAN Testers (t/integration.t "degrades gracefully without BSD::Resource" subtest, App-Test-Generator-0.41).
Documentation
Generate Benchmark harnesses from ATG schema files
Demonstrate the schema extractor
Deploy ATG GitHub Actions workflows to a CPAN module repository
Extract test schemas from Perl modules
Generate fuzzing + corpus-based test harnesses from test schemas
Generate round-trip tests from POD code examples
Test coverage dashboard generator
Run mutation testing against a Perl test suite
Modules
Fuzz Testing, Mutation Testing, LCSAJ Metrics and Test Dashboard for Perl modules
Generate Benchmark harnesses from ATG schemas
AFL-style coverage-guided fuzzing for App::Test::Generator
Serialise a test plan to YAML
Static LCSAJ extraction for Perl
Merge LCSAJ path data with runtime hits
Evidence-based model of a single method under test
Negate boolean return expressions to expose missing assertion coverage
Replace return expressions with undef to expose missing undef-return checks in the test suite
Generate and apply mutation tests
Extract runnable code examples from a Perl module's POD
Example module for schema extraction testing
Extract test schemas from Perl modules
Template for the test files generated by App::Test::Generator
Debugger backend for LCSAJ coverage
Provides
in lib/App/Test/Generator/Analyzer/Complexity.pm
in lib/App/Test/Generator/Analyzer/Return.pm
in lib/App/Test/Generator/Analyzer/ReturnMeta.pm
in lib/App/Test/Generator/Analyzer/SideEffect.pm
in lib/App/Test/Generator/Emitter/Perl.pm
in lib/App/Test/Generator/Mutant.pm
in lib/App/Test/Generator/Mutation/Base.pm
in lib/App/Test/Generator/Mutation/ConditionalInversion.pm
in lib/App/Test/Generator/Mutation/NumericBoundary.pm
in lib/App/Test/Generator/Planner.pm
in lib/App/Test/Generator/Planner/Fixture.pm
in lib/App/Test/Generator/Planner/Grouping.pm
in lib/App/Test/Generator/Planner/Isolation.pm
in lib/App/Test/Generator/Planner/Mock.pm
in lib/App/Test/Generator/TestStrategy.pm