Command Center

Refactoring Agent Examples

Eliminate duplication

📄 players/views.py
-18 lines+11 linesExtract Mixin
Source: github.com/jkoppel/django-battleships/pull/1
Extract Mixin
BEFOREAuth logic mixed with business logic
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@method_decorator(login_required, name='dispatch')
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class AdminManageUsersView(View):
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    def get(self, request, *args, **kwargs):
×2 DUPLICATED
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        # Check if the current user is an admin
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        try:
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            player = Player.objects.get(user=request.user)
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            if not player.is_admin:
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                return HttpResponseForbidden("...")
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        except Player.DoesNotExist:
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            return HttpResponseForbidden("...")
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        # Get all users...
...
        ...
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    def post(self, request, *args, **kwargs):
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        # Check if the current user is an admin
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        try:
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            player = Player.objects.get(user=request.user)
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            if not player.is_admin:
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                return HttpResponseForbidden("...")
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        except Player.DoesNotExist:
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            return HttpResponseForbidden("...")
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        # Handle user deletion...
NEW CLASSline 10
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class AdminRequiredMixin(LoginRequiredMixin):
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    """Mixin to require admin status."""
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    def dispatch(self, request, *args, **kwargs):
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        try:
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            player = Player.objects.get(user=request.user)
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        except Player.DoesNotExist:
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            return HttpResponseForbidden("...")
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        if not player.is_admin:
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            return HttpResponseForbidden("...")
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        return super().dispatch(request, *args, **kwargs)
AFTERAuth logic cleanly separated
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class AdminManageUsersView(AdminRequiredMixin, View):
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    def get(self, request, *args, **kwargs):
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        # Get all players and map...
...
        ...
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    def post(self, request, *args, **kwargs):
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        # Handle user deletion...

Remove indirection

📄 pages/_app.tsx
-4 linesRemove Indirection
Source: github.com/jkoppel/langfuse/pull/2
BEFOREUnnecessary wrapper function
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                      <Layout>
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                        <Component {...pageProps} />
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                        <UserTracking />
USELESS WRAPPER
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                        <LoginTracking />
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                      </Layout>
...
...
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function LoginTracking() {
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  return <LoginTracker />;
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}
AFTERDirect component usage
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                      <Layout>
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                        <Component {...pageProps} />
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                        <UserTracking />
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                        <LoginTracker />
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                      </Layout>
...

Separate logic

📄 features/auth/hooks.ts → features/auth/storage.ts
-25 lines+3 linesExtract Storage Logic
Source: github.com/jkoppel/langfuse/pull/2
BEFOREStorage logic mixed with UI hook
...
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export const useLastUsedLogin = () => {
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  const [logins, setLogins] = useState<LastUsedLogin[]>([]);
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  // Load from localStorage on mount
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  useEffect(() => {
UI HOOK+ STORAGE LOGIC
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    if (typeof window === "undefined") return;
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    try {
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      const stored = localStorage.getItem(STORAGE_KEY);
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      if (stored) {
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        const parsed = JSON.parse(stored) as LastUsedLogin[];
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        // Filter out expired entries
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        const now = Date.now();
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        const valid = parsed.filter(
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          (login) =>
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            now - login.timestamp < EXPIRATION_DAYS * 24 * 60 * 60 * 1000,
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        );
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        setLogins(valid);
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        // Update localStorage if we filtered anything
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        if (valid.length !== parsed.length) {
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          localStorage.setItem(STORAGE_KEY, JSON.stringify(valid));
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        }
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      }
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    } catch (error) {
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      console.error("Failed to load last used logins:", error);
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    }
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  }, []);
...
NEW MODULEfeatures/auth/storage.ts
Separated Storage Logic
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export function loadLastUsedLogins(): LastUsedLogin[] {
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  const stored = safeGetJson<LastUsedLogin[]>(
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    localStorage,
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    LAST_USED_STORAGE_KEY,
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  );
...
  // Filter expired, update storage...
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}
AFTERUI HOOK ONLY
Clean separation
...
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export const useLastUsedLogin = () => {
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  const [logins, setLogins] = useState<LastUsedLogin[]>([]);
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  // Load from localStorage on mount
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  useEffect(() => {
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    const loaded = loadLastUsedLogins();
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    setLogins(loaded);
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  }, []);
...