## Testing Standards

### Test Structure (AAA Pattern)

```typescript
test('calculates similarity correctly', () => {
  // Arrange
  const vector1 = [1, 0, 0]
  const vector2 = [0, 1, 0]

  // Act
  const similarity = calculateCosineSimilarity(vector1, vector2)

  // Assert
  expect(similarity).toBe(0)
})
```

### Test Naming

```typescript
// ✅ GOOD: Descriptive test names
test('returns empty array when no markets match query', () => { })
test('throws error when OpenAI API key is missing', () => { })
test('falls back to substring search when Redis unavailable', () => { })

// ❌ BAD: Vague test names
test('works', () => { })
test('test search', () => { })
```