Circular Dependencies (Modules)

The Problem

{
  "modules": {
    "ModuleA": ["services/ServiceA.ts"],
    "ModuleB": ["services/ServiceB.ts"]
  }
}

// ServiceA (ModuleA) depends on ServiceB (ModuleB)
export class ServiceA implements IServiceA {
  constructor(private serviceB: IServiceB) {}
  doSomething(): string {
    return 'A: ' + this.serviceB.doSomething();
  }
}

// ServiceB (ModuleB) depends on ServiceA (ModuleA)
export class ServiceB implements IServiceB {
  constructor(private serviceA: IServiceA) {}
  doSomething(): string {
    return 'B: ' + this.serviceA.doSomething();
  }
}

The Cycle: ModuleA → ModuleB → ModuleA → impossible to load!

Detection

❌ Error: Circular dependency detected between modules.

Module dependency chain:
  ModuleA → ModuleB → ModuleA

Detailed circular dependency:
  ServiceA (ModuleA) → IServiceB (ServiceB in ModuleB) → IServiceA (ServiceA in ModuleA)

Modules involved in circular dependencies:
  - ModuleA: services/ServiceA.ts
  - ModuleB: services/ServiceB.ts

How to Fix

Merge modules or extract common dependency:

// ✅ Extract shared service
class SharedService {
  doSomething(): string {
    return 'shared logic';
  }
}

// ModuleA
class ServiceA {
  constructor(private shared: SharedService) {}
}

// ModuleB
class ServiceB {
  constructor(private shared: SharedService) {}
}