Constructors can't redirect to themselves either directly or indirectlyDRT-W1584

The analyzer produces this diagnostic when a constructor redirects to itself, either directly or indirectly, creating an infinite loop.

Examples

The following code produces this diagnostic because the generative constructors C.a and C.b each redirect to the other:

class C {
  C.a() : this.b();
  C.b() : this.a();
}

The following code produces this diagnostic because the factory constructors A and B each redirect to the other:

abstract class A {
  factory A() = B;
}
class B implements A {
  factory B() = A;
  B.named();
}

Common fixes

In the case of generative constructors, break the cycle by finding defining at least one of the constructors to not redirect to another constructor:

class C {
  C.a() : this.b();
  C.b();
}

In the case of factory constructors, break the cycle by defining at least one of the factory constructors to do one of the following:

• Redirect to a generative constructor:

abstract class A {
  factory A() = B;
}
class B implements A {
  factory B() = B.named;
  B.named();
}

• Not redirect to another constructor:

abstract class A {
  factory A() = B;
}
class B implements A {
  factory B() {
    return B.named();
  }

  B.named();
}

• Not be a factory constructor:

abstract class A {
  factory A() = B;
}
class B implements A {
  B();
  B.named();
}