Fallow - Codebase Health

Version updated for https://github.com/fallow-rs/fallow to version v2.35.0.

• This action is used across all versions by 7 repositories.

Action Type

This is a Composite action.

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Action Summary

This GitHub Action, “Fallow,” is a Rust-based codebase analyzer designed for TypeScript and JavaScript projects. It automates the detection of unused code, duplication, complexity issues, and architectural problems, providing rapid insights without requiring configuration. Fallow helps streamline code maintenance by offering capabilities such as dead code identification, circular dependency detection, and boundary violation auditing, making it a valuable tool for improving code quality and maintainability.

What’s Changed

Severity Tiers for Health Findings

Every complexity finding now has a severity field that tells you how urgently it needs attention:

Thresholds are asymmetric because cognitive complexity maps more directly to comprehension difficulty.

In practice

{
  "name": "processOrder",
  "cyclomatic": 57,
  "cognitive": 90,
  "exceeded": "both",
  "severity": "critical"
}

Summary includes severity breakdown:

{
  "functions_above_threshold": 24,
  "severity_critical_count": 10,
  "severity_high_count": 7,
  "severity_moderate_count": 7
}

Human output shows CRITICAL and HIGH badges on findings. Moderate findings are visually silent (no badge noise for the baseline tier).

CI exit code filtering

New --min-severity flag controls which findings cause exit code 1:

# Only fail on critical findings (ignore moderate/high)
fallow health --min-severity critical

# Default: any finding causes failure (same as before)
fallow health

MI Formula Fix for Small Files

The Maintainability Index formula previously used complexity_density = cyclomatic / LOC as its dominant term. This caused a 5-line type-guard function (density 0.40) to score worse than a 192-line nightmare function with 57 cyclomatic complexity (density 0.30).

Before: MI = 100 - (density × 30) - (dead_code × 20) - fan_out_penalty After: MI = 100 - (density × 30 × dampening) - (dead_code × 20) - fan_out_penalty

Where dampening = min(lines / 50, 1.0). Files under 50 lines get proportionally reduced density weight.

SNAPSHOT_SCHEMA_VERSION bumped to v7. Existing --save-snapshot data will not compare against pre-v7 snapshots.

All changes

Added

• Severity tiers on health findings (moderate/high/critical) across all 6 output formats (#119)
• --min-severity CLI flag for exit code filtering
• Health finding test fixtures in GitHub Action and GitLab CI jq tests

Fixed

• MI formula distorted for small files (#118)
• Integration test fixture for bin-script dependency resolution tracked in git

Full Changelog: https://github.com/fallow-rs/fallow/compare/v2.34.0...v2.35.0

• Fallow-Rs
• GitHub Actions