headroom/tests/test_compression
Veesh Goldman f39858c233
feat(code): add Perl support to code-aware compressor (#1125)
## Description

Adds Perl as a supported language for `CodeAwareCompressor` /
`CodeStructureHandler`. Function bodies are compressed while
`use`/`require` imports, `sub`/`method` signatures, and
`package`/`class`/`role` declarations are preserved — bringing Perl up
to parity with the other Tier-2 languages.

No new dependencies: the Perl grammar already ships in
`tree-sitter-language-pack` (already a Headroom dependency), so this is
pure configuration.

Closes #

## Type of Change

- [ ] Bug fix (non-breaking change that fixes an issue)
- [x] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- `code_handler.py`: Perl entries in the four per-language tables —
`_STRUCTURAL_NODE_TYPES`, `_SIGNATURE_PATTERNS` (regex fallback),
`_LANGUAGE_MARKERS` (detection), `_IMPORT_PATTERNS`. The existing
`_CONTAINER_BODY_TYPES` already covers Perl's `block` body node, so no
change was needed there.
- `code_compressor.py`: `CodeLanguage.PERL` enum value, a data-driven
`LangConfig`, a `_LANGUAGE_PREFILTER` entry, and the supported-language
string in the parser error message.
- Node-type names (`subroutine_declaration_statement`,
`package_statement`, `signature`, `block`, …) are from the
`tree-sitter-perl/tree-sitter-perl` grammar (MIT).
- Tests: 1 detection test + 2 regex-path signature/import-preservation
tests.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ pytest tests/test_compression/test_code_handler.py -q
collected 28 items
tests/test_compression/test_code_handler.py ............................ [100%]
======================== 28 passed, 1 warning in 2.53s =========================

$ ruff check headroom/compression/handlers/code_handler.py headroom/transforms/code_compressor.py tests/test_compression/test_code_handler.py
All checks passed!

$ mypy headroom/compression/handlers/code_handler.py headroom/transforms/code_compressor.py
Success: no issues found in 2 source files
```

## Real Behavior Proof

- Environment: Python 3.12, `pip install -e ".[code]"`
(tree-sitter-language-pack installed, `is_tree_sitter_available() ==
True`).
- Exact command / steps: ran `CodeStructureHandler().get_mask(code,
language="perl")` on a real Perl module (package + two subs with
bodies).
- Observed result: detected as `perl`, parsed via the `tree-sitter` path
(not regex), and the preserved span was exactly the imports + package +
sub signatures, with both sub bodies marked compressible:

```text
tree-sitter available: True
parser: tree-sitter | detected: perl
--- PRESERVED (signatures/imports/structure) ---
use strict;use warnings;package Greeter;sub new sub greet
```

- Not tested: the full proxy/MCP server end-to-end path (out of scope —
this PR only touches the code compressor's language tables).

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

## Additional Notes

- Docs/CHANGELOG left unchecked — happy to add a Perl line to either if
you'd like; I wasn't sure of your preferred location.
- *Disclosure: I maintain the upstream `tree-sitter-perl` grammar this
relies on. It's already a transitive dependency of Headroom via
`tree-sitter-language-pack` — this PR only adds config to use it, with
no dependency changes.*

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-22 18:47:41 -05:00
..
__init__.py Add universal compression module with ML-based content detection 2026-01-15 15:26:14 -08:00
test_code_handler.py feat(code): add Perl support to code-aware compressor (#1125) 2026-06-22 18:47:41 -05:00
test_evals.py Remove LLMLingua: Kompress is the sole text compressor 2026-03-26 11:11:00 -07:00
test_json_handler.py fix(compression): measure short-value threshold on payload, not token (#889) 2026-06-15 10:23:26 -05:00
test_llm_eval.py Remove LLMLingua: Kompress is the sole text compressor 2026-03-26 11:11:00 -07:00
test_masks.py Add universal compression module with ML-based content detection 2026-01-15 15:26:14 -08:00
test_universal.py Remove LLMLingua: Kompress is the sole text compressor 2026-03-26 11:11:00 -07:00