property-testinglisted
Install: claude install-skill majiayu000/claude-skill-registry-data
# Property Testing
LivestockAI uses property-based testing (PBT) with fast-check to validate business logic invariants.
## What is Property Testing?
Instead of testing specific examples, property tests verify that properties hold for ALL possible inputs:
```typescript
// Example-based test
it('calculates FCR correctly', () => {
expect(calculateFCR(150, 100)).toBe(1.5)
})
// Property-based test
it('FCR is always positive when inputs are positive', () => {
fc.assert(
fc.property(
fc.float({ min: 0.1, max: 10000 }),
fc.float({ min: 0.1, max: 10000 }),
(feed, weight) => {
const fcr = calculateFCR(feed, weight)
return fcr === null || fcr > 0
},
),
)
})
```
## fast-check Basics
```typescript
import { describe, it, expect } from 'vitest'
import * as fc from 'fast-check'
describe('Property Tests', () => {
it('property holds for all inputs', () => {
fc.assert(
fc.property(fc.integer({ min: 1, max: 100000 }), (quantity) => {
// Property must return true or throw
return quantity > 0
}),
{ numRuns: 100 },
)
})
})
```
## Common Arbitraries
```typescript
// Integers
fc.integer({ min: 1, max: 100000 })
fc.nat() // Non-negative integer
// Floats
fc.float({ min: 0, max: 10000 })
// Strings
fc.string()
fc.uuid()
// Arrays
fc.array(fc.integer(), { minLength: 0, maxLength: 20 })
// Objects
fc.record({
quantity: fc.integer({ min: 1, max: 1000 }),
price: fc.float({ min: 0, max: 100