sprint10-testing-patterns

Sprint 10 Testing Patterns - Prevention Through Testing

🎯 GOAL: Catch Sprint 10 Issues Before They Become Problems

These testing patterns specifically target the 5 critical failure modes identified in Sprint 10.

🔥 HYDRATION ERROR TESTING

Pre-Commit Hydration Testing

# MANDATORY before any theme/client-side commits
#!/bin/bash
echo "🧪 Testing for hydration issues..."

# 1. Production build test (catches 90% of hydration issues)
npm run build
if [ $? -ne 0 ]; then
  echo "❌ Build failed - fix before committing"
  exit 1
fi

# 2. Start production server and test both themes
npm start &
SERVER_PID=$!
sleep 5

# 3. Check for hydration errors in browser console
# Use Browser Tools MCP if available
mcp_browser-tools_takeScreenshot || echo "⚠️ MCP not available, manual test required"

kill $SERVER_PID
echo "✅ Hydration test complete"

Component-Level Hydration Testing

// Test file: __tests__/hydration.test.tsx
import { renderToString } from 'react-dom/server';
import { render } from '@testing-library/react';

describe('Hydration Safety', () => {
  test('Theme Provider renders consistently', () => {
    const ThemeWrapper = ({ children }) => (
      <ChakraProvider theme={theme}>{children}</ChakraProvider>
    );
    
    // Server render
    const serverHTML = renderToString(<ThemeWrapper><App /></ThemeWrapper>);
    
    // Client render
    const { container } = render(<ThemeWrapper><App /></ThemeWrapper>);
    
    // Should match (simplified check)
    expect(container.innerHTML).toContain('expected-theme-class');
  });
  
  test('No browser APIs in initial render', () => {
    // Mock browser APIs to undefined
    Object.defineProperty(window, 'localStorage', { value: undefined });
    Object.defineProperty(window, 'innerWidth', { value: undefined });
    
    // Should not throw during render
    expect(() => {
      render(<App />);
    }).not.toThrow();
  });
});

🔥 CIRCULAR IMPORT TESTING

Backend Import Validation

# backend/tests/test_imports.py
import ast
import os
from pathlib import Path

def test_no_main_imports_in_routers():
    """Ensure routers never import from main.py"""
    router_dir = Path("backend/routers")
    violations = []
    
    for py_file in router_dir.glob("*.py"):
        with open(py_file, 'r') as f:
            content = f.read()
            
        # Parse AST to find imports
        tree = ast.parse(content)
        for node in ast.walk(tree):
            if isinstance(node, ast.ImportFrom):
                if node.module and "main" in node.module:
                    violations.append(f"{py_file}: {ast.unparse(node)}")
    
    assert not violations, f"Found main.py imports in routers: {violations}"

def test_dependency_injection_usage():
    """Ensure routers use Depends() pattern"""
    router_dir = Path("backend/routers")
    
    for py_file in router_dir.glob("*.py"):
        if py_file.name == "__init__.py":
            continue
            
        with open(py_file, 'r') as f:
            content = f.read()
            
        # Should use Depends() for shared resources
        assert "Depends(" in content, f"{py_file} should use dependency injection"
        assert "from ..dependencies import" in content, f"{py_file} should import from dependencies"