Code health check

<!-- WHY: D1 (Activation Protocol) — Load check definitions and scoring before running any analysis. Without this, checks are ad-hoc and inconsistent. -->

Code Health Check

Automated codebase health analysis with scored report and prioritized fixes.

When to use: Before a release, during sprint planning, onboarding to a new codebase, or anytime you need a structured quality snapshot.

When NOT to use: For runtime debugging (use a debugger). For security-specific audits (use a dedicated security tool). This is a structural health check, not a pentest.

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Activation Protocol

Before running any checks:

1. Load check definitions: Read references/health-checks.md
2. Load scoring: Read references/scoring-methodology.md
3. Detect project type: Glob for package.json, pyproject.toml, Cargo.toml, go.mod
4. Scope the check:
   • If $ARGUMENTS provided, use as path scope
   • If not, use current working directory
5. Verify it's a code repo: Check for .git/ or source files
   • If no code found: "This doesn't appear to be a codebase. Point me to a project directory."

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<!-- WHY: D5 (Question System) — If scope is ambiguous, ask before running a potentially expensive analysis on the wrong directory. -->

Question System

Input	Required	If Missing
Target path	Yes	Ask: "Which directory should I analyze?"
Depth	No	Default: full (all 5 dimensions)
Exclusions	No	Default: node_modules, .git, dist, build, vendor

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Core Instructions

Run 5 health dimensions in sequence. Each produces a 0-100 score.

Dimension 1: Dead Code (weight: 15%)

# Find unused exports
grep -r "export " --include="*.ts" --include="*.js" | # extract export names
# Cross-reference with imports across codebase
# Unused export = dead code candidate

• Glob all source files
• Extract exported symbols (functions, classes, constants)
• Grep for imports/usage of each symbol
• Score: 100 - (dead_exports / total_exports × 100)

Dimension 2: Dependency Health (weight: 20%)

• Read package.json / requirements.txt / Cargo.toml
• Check last publish date of each dependency (if available via Bash)
• Flag: dependencies > 1 year old, deprecated packages, known CVEs
• Score: 100 - (stale_deps / total_deps × 100)

Dimension 3: Test Coverage (weight: 25%)

• Glob test files (.test., .spec., test_*, _test.)
• Glob source files
• Calculate ratio: test_files / source_files
• Check for test configuration (jest.config, pytest.ini, etc.)
• Score: (test_ratio × 50) + (has_config × 25) + (has_ci × 25)

Dimension 4: Security Surface (weight: 20%)

• Grep for hardcoded secrets (API keys, tokens, passwords)
• Check for eval(), exec(), dangerouslySetInnerHTML
• Check .env.example exists (if .env is gitignored)
• Check dependency audit (npm audit / pip-audit)
• Score: 100 - (findings × 10), min 0

Dimension 5: Complexity Hotspots (weight: 20%)

• Find files > 500 lines (candidates for splitting)
• Find functions > 50 lines (candidates for extraction)
• Find deeply nested code (> 4 levels of indentation)
• Score: 100 - (hotspots / total_files × 100)

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<!-- WHY: D4 (Quality Gate) — The report must meet these criteria before being presented to the user. Prevents low-quality analysis. -->

Quality Gate

Before presenting the report, verify:

• All 5 dimensions produced a numeric score (0-100)
• At least 10 files were analyzed (otherwise scope is too narrow)
• Each finding has a specific file path (not generic advice)
• Remediation priorities are ordered by impact (not alphabetically)

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<!-- WHY: D7 (Pre-Execution Gate) — Verify preconditions before running the potentially expensive analysis. -->

Pre-Execution Gate

Before running checks:

• Target directory exists and contains source files
• At least one recognized language detected
• Not running inside node_modules or .git
• Sufficient context to complete analysis

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<!-- WHY: D14 (Graceful Degradation) — Handle repos that are missing tests, deps, or other expected structures without crashing. -->

Degradation Handling

Missing Element	Behavior
No tests at all	Score dimension 3 at 0, note "No test infrastructure detected"
No package manager	Skip dimension 2, note "No dependency manifest found"
Binary/generated files	Exclude from analysis, note count
Monorepo	Ask which package to analyze, or run on root
Empty directories	Skip, don't count as dead code

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<!-- WHY: D2 (Anti-Pattern Guard) — Common mistakes when doing health checks. -->

Anti-Patterns

1. Counting lines as quality — More lines ≠ worse. Measure complexity, not volume.
2. Flagging all old dependencies — Stable deps (lodash, express) being "old" is fine.
3. Test file ratio as coverage — File existence ≠ meaningful test coverage.
4. Generic advice — "You should write more tests" is useless. Specify WHICH files need tests.
5. Ignoring context — A prototype has different health standards than production code.
6. Running on vendor code — Always exclude node_modules, vendor, generated code.
7. One-time snapshot thinking — Health checks should be re-run periodically, not once.

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<!-- WHY: D16 (Composability) — No hardcoded paths. Works in any project. -->

Output Format

CODE HEALTH REPORT — {project_name}
Generated: {date} | Scope: {path} | Files: {N}

OVERALL HEALTH: {score}/100 {grade}

  Dead Code        {score}/100  ████████░░  {dead_count} unused exports
  Dependencies     {score}/100  ██████████  {stale_count} stale, {vuln_count} vulnerable
  Test Coverage    {score}/100  ██████░░░░  {test_ratio}% file coverage
  Security Surface {score}/100  █████████░  {finding_count} findings
  Complexity       {score}/100  ████████░░  {hotspot_count} hotspots

TOP PRIORITIES (fix these first):
  1. {file:line} — {issue} — {impact}
  2. {file:line} — {issue} — {impact}
  3. {file:line} — {issue} — {impact}

DETAILED FINDINGS: {N} total across 5 dimensions
  [See below for per-dimension breakdown]

Grade scale: A (90+), B (75-89), C (60-74), D (40-59), F (<40)