cherrypick/website/docs/advanced-features/circular-dependency-detection.md

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Circular Dependency Detection

CherryPick can detect circular dependencies in your DI configuration, helping you avoid infinite loops and hard-to-debug errors.

How to use:

1. Enable Cycle Detection for Development

Local detection (within one scope):

final scope = CherryPick.openSafeRootScope(); // Local detection enabled by default
// or, for an existing scope:
scope.enableCycleDetection();

Global detection (across all scopes):

CherryPick.enableGlobalCrossScopeCycleDetection();
final rootScope = CherryPick.openGlobalSafeRootScope();

2. Error Example

If you declare mutually dependent services:

class A { A(B b); }
class B { B(A a); }

scope.installModules([
  Module((bind) {
    bind<A>().to((s) => A(s.resolve<B>()));
    bind<B>().to((s) => B(s.resolve<A>()));
  }),
]);

scope.resolve<A>(); // Throws CircularDependencyException

3. Typical Usage Pattern

• Always enable detection in debug and test environments for maximum safety.
• Disable detection in production for performance (after code is tested).

import 'package:flutter/foundation.dart';

void main() {
  if (kDebugMode) {
    CherryPick.enableGlobalCycleDetection();
    CherryPick.enableGlobalCrossScopeCycleDetection();
  }
  runApp(MyApp());
}

4. Handling and Debugging Errors

On detection, CircularDependencyException is thrown with a readable dependency chain:

try {
  scope.resolve<MyService>();
} on CircularDependencyException catch (e) {
  print('Dependency chain: ${e.dependencyChain}');
}