logicrepo

A CLI tool that validates business logic defined in YAML files. Runs in CI to block PRs with invalid or risky logic changes.

Why

Separate business logic from application code. Define rules as version-controlled YAML, test them in CI, and review changes in PR diffs.

Quick Start

# Run directly with npx
npx logicrepo check

# Or install globally
npm install -g logicrepo
logicrepo check

Example

Rule: logic/rules/pricing.yaml

version: 1
rules:
  - id: enterprise_discount
    description: "Enterprise customers get 20% off"
    when:
      customer_tier: enterprise
    then:
      discount_percent: 20

  - id: default_pricing
    when: {}
    then:
      discount_percent: 0

Test: logic/tests/pricing_tests.yaml

version: 1
tests:
  - name: enterprise customer gets discount
    input:
      customer_tier: enterprise
    expect:
      discount_percent: 20
      matched_rule: enterprise_discount

Output:

Loading rules...
  ✓ logic/rules/pricing.yaml (2 rules)

Running tests...
  ✓ logic/tests/pricing_tests.yaml (1 passed)

✓ All 1 tests passed

Documentation

| Document | Description | |----------|-------------| | Getting Started | Create your first rules and tests | | Rules Reference | Complete rule syntax and operators | | Examples | Real-world examples: pricing, access control, feature flags | | Best Practices | Patterns, anti-patterns, and code review checklist |

CI Integration

# .github/workflows/logic-check.yml
name: Logic Check
on: [pull_request]
jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
      - run: npx logicrepo check

Key Concepts

• First match wins: Rules evaluated in order; first match returns
• Deterministic: Same input always produces same output
• Stateless: Rules only see the input, nothing else
• Strict equality: No type coercion ("100" ≠ 100)

Directory Structure

logic/
├── rules/     # Business logic (YAML)
└── tests/     # Test scenarios (YAML)

CLI

logicrepo check              # Validate rules and run tests
logicrepo check --dir ./path # Custom logic directory

Exit code 0 = all tests pass. Exit code 1 = failures (blocks CI).