Baseline Check Skill

An autonomous Claude Code skill that tracks code quality baselines throughout the development lifecycle.

Overview

The baseline-check skill provides automated quality tracking by:

Running RuboCop (Ruby style/lint checks) and RSpec (test suite)
Establishing quality baselines before development work
Detecting regressions after code changes
Comparing metrics across development sessions
Providing actionable feedback on code health

How It Works

Autonomous Activation

This skill activates automatically when Claude detects relevant triggers:

Before starting development work
After completing code changes
When quality concerns are mentioned
Before creating pull requests
When running tests is appropriate

Quality Tracking Process

Execute Checks: Runs baseline-check.sh wrapper script
Capture Metrics: Saves results to .claude/baseline/{branch}-{timestamp}.json
Compare Baselines: Finds previous baseline for the same branch
Analyze Trends: Identifies improvements, regressions, or stability
Report Findings: Provides clear, actionable feedback

Components

1. SKILL.md

Instructs Claude on when and how to use the skill, including:

Trigger conditions for autonomous activation
Step-by-step execution instructions
Baseline comparison logic
Report formatting guidelines

2. baseline-check.sh

Wrapper script that:

Executes RuboCop and RSpec via bundle exec
Outputs standardized JSON format
Gracefully handles missing tools
Tracks git branch and commit context
Measures execution time

3. Baseline Storage

Quality snapshots stored in .claude/baseline/:

Format: {branch}-{yyyymmdd-hhmmss}.json
Timestamped for comparison over time
Branch-specific for isolation
Gitignored (local development artifacts)

JSON Output Schema

{
  "timestamp": "2025-11-17T09:15:42Z",
  "branch": "feat/new-feature",
  "commit": "abc123f",
  "checks": {
    "rubocop": {
      "available": true,
      "status": "passed",
      "files_inspected": 15,
      "offenses": 3,
      "offenses_by_severity": {
        "convention": 2,
        "warning": 1,
        "error": 0,
        "fatal": 0
      },
      "execution_time": 1.45
    },
    "rspec": {
      "available": true,
      "status": "passed",
      "examples": 42,
      "failures": 0,
      "pending": 2,
      "execution_time": 3.21
    }
  },
  "overall_status": "passed",
  "summary": "All checks passed"
}

Usage

Manual Execution

Run the script directly from project root:

./.claude/skills/baseline-check/baseline-check.sh

Autonomous Execution

The skill runs automatically when Claude determines it's appropriate. No explicit invocation needed.

Exit Codes

0 - Success (all checks passed or none available)
1 - Check failures (one or more checks failed)
2 - Script error (not in git repo, JSON generation failed)

Example Workflow

Initial Baseline

User: "I want to add SSH support to the provider"

Claude: [baseline-check skill activates]
Running quality baseline check...

Baseline Quality Check - Initial Assessment
==========================================

Branch: main
Commit: 168d4ea

RuboCop: 15 files, 0 offenses ✓
RSpec: 42 examples, 0 failures ✓

Overall Status: PASSED ✓

This is the first baseline for this branch. Future checks will compare against these metrics.

[Proceeds with implementation...]

Post-Development Comparison

Claude: [After implementation, baseline-check skill activates again]
Running quality baseline check...

Baseline Quality Check - Regression Analysis
============================================

RuboCop Changes:
  Files Inspected: 15 → 18 (+3)
  Total Offenses: 0 → 2 (+2) ⚠️ REGRESSION
    - Convention: 0 → 2 (+2)

RSpec Changes:
  Examples: 42 → 48 (+6) ✓ IMPROVEMENT
  Failures: 0 → 0 (stable)

FINDINGS:
⚠️  2 new RuboCop convention offenses
✓  6 new tests added

RECOMMENDATION:
Consider addressing the new RuboCop offenses before committing.
Run 'bundle exec rubocop -a' to auto-fix.

Integration Points

Git Workflow

Pre-commit: Establish baseline before changes
Post-implementation: Detect regressions
Pre-push: Ensure quality standards met

Development Cycle

Feature start: Initial quality snapshot
During development: Periodic checks
Feature complete: Final verification
Pull request: Include quality metrics

Quality Gates

Block commits with fatal errors or test failures
Warn on convention/warning increases
Celebrate quality improvements

Best Practices

Run Before Starting: Establishes clean baseline
Run After Changes: Catches issues early
Don't Ignore Warnings: Small regressions accumulate
Fix Criticals First: Never commit with fatals/errors/failures
Track Trends: Review baselines over feature lifecycle

Requirements

Git repository (must be run from within repo)
Ruby project with Bundler
Optional: RuboCop gem (for style checks)
Optional: RSpec gem (for test suite)
Optional: jq (for prettier JSON, falls back gracefully)

Maintenance

The skill is designed to be:

Self-contained: All files colocated in skill directory
Portable: No hardcoded paths, works in any Ruby project
Robust: Handles missing tools gracefully
Extensible: Easy to add new quality checks
Informative: Clear logging and detailed reports

Files

.claude/skills/baseline-check/
├── SKILL.md              # Claude instructions for skill execution
├── baseline-check.sh     # Wrapper script for quality checks
└── README.md            # This file - skill documentation

baseline-check