Test Guided Debloating

What it does

When your agent uses it

• You need to debloat
• Remove unused code from a codebase based on test coverage
• Users ask to remove unused code
• Debloat based on tests

Example prompts

• “Use the test-guided-debloating skill to remove unnecessary code from a repository while preserving exactly the behavior exercised by a given test…”
• “/test-guided-debloating”

Requirements

• Python 3

Workflow steps

6 steps, taken from the step headings in SKILL.md.

1. 1Understand Requirements
2. 2Run Coverage Analysis
3. 3Analyze Coverage Data
4. 4Incremental Removal
5. 5Validate Preservation of Behavior
6. 6Document Changes

What it can do on your machine

Read from SKILL.md and the folder at commit 4f38503. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships 1 file in scripts/ (Python), which the agent can run.

  Shell commands in SKILL.md call:

  • python
  • pytest
  • npm
  • mvn

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md. Its commands use npm, which can reach the network depending on how they are called.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Test Guided Debloating loads about 1.5k tokens when it runs, and up to ~4.7k if it reads all its reference files. Until then it costs about 163 tokens; SKILL.md has 429 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~163

When it runs · the whole SKILL.md, loaded when a task matches

~1.5k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~4.7k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from ArabelaTso/Skills-4-SE at commit 4f38503, republished under its Apache-2.0 licence (© ArabelaTso). 429 words, ~1,473 tokens.

name

test-guided-debloating

description

Removes unnecessary code from a repository while preserving exactly the behavior exercised by a given test suite. Use this skill when you need to debloat, slim down, or remove unused code from a codebase based on test coverage. The skill analyzes which code elements (files, classes, functions, methods, branches, imports) are exercised by tests, identifies unreachable or unused code, and safely removes it while ensuring all tests continue to pass. Triggers when users ask to remove unused code, debloat based on tests, eliminate dead code guided by test coverage, or slim down a repository to only test-required functionality.

pytest --cov=. --cov-report=json --cov-report=html

npm test -- --coverage --coverageReporters=json --coverageReporters=html

mvn clean test jacoco:report

python scripts/analyze_coverage.py coverage.json --output analysis.json

# Run full test suite
<test_command>

# Verify all tests pass
# Check for import errors
# Verify build succeeds

DEBLOATING SUMMARY
==================

Removed Elements:
- 15 unused files
- 42 unused functions
- 8 unused classes
- 156 unused imports
- 23 dead branches

Total lines removed: 3,847
Tests passing: 156/156

Preservation Justification:
All test-defined behavior is preserved because:
1. All test-covered code remains intact
2. All transitive dependencies of test-covered code remain
3. No side effects required by tests were removed
4. Build succeeds and all 156 tests pass

# Analyze Python coverage
python scripts/analyze_coverage.py coverage.json

# Analyze JavaScript coverage
python scripts/analyze_coverage.py coverage-final.json --format javascript

# Save detailed analysis
python scripts/analyze_coverage.py coverage.json --output analysis.json

© ArabelaTso, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 3 other files (scripts, references) in skills/test-guided-debloating of ArabelaTso/Skills-4-SE.

• SKILL.md
• references/coverage_tools.md
• references/debloating_strategy.md
• scripts/analyze_coverage.py

Open the folder on GitHubat commit 4f38503