tdd-workflows-tdd-green

Green Phase: Simple function

def product_list(request):
products = Product.objects.all()
return JsonResponse({'products': list(products.values())})

Refactor: Class-based view

class ProductListView(View):
def get(self, request):
products = Product.objects.all()
return JsonResponse({'products': list(products.values())})

Refactor: Generic view

class ProductListView(ListView):
model = Product
context_object_name = 'products'

### Express Patterns
Inline → Middleware → Service Layer:

javascript
// Green Phase: Inline logic
app.post('/api/users', (req, res) => {
const user = { id: Date.now(), ...req.body };
users.push(user);
res.json(user);
});

// Refactor: Extract middleware
app.post('/api/users', validateUser, (req, res) => {
const user = userService.create(req.body);
res.json(user);
});

// Refactor: Full layering
app.post('/api/users',
validateUser,
asyncHandler(userController.create)
);
``

Use this skill when

Moving from red to green in a TDD cycle

Implementing minimal behavior to satisfy tests

You want to keep implementation intentionally simple

Do not use this skill when

You are refactoring for design or performance

Tests are already passing and you need new requirements

You need a full architectural redesign

Instructions

Review failing tests and identify the smallest fix.

Implement the minimal change to pass the next test.

Run tests after each change to confirm progress.

Record shortcuts or debt for the refactor phase.

Safety

Avoid bypassing tests to make them pass.

Keep changes scoped to the failing behavior only.

Resources

resources/implementation-playbook.md` for detailed patterns and examples.