prefer-switch-with-sealed-classes

added in: 1.17.0

Pro+

Suggests to use a switch statement or expression instead of conditionals with sealed class instances.

When it comes to sealed classes, the analyzer warns you when a new class is not covered by a switch case. This feature is not available for if statements and conditional expressions.

Therefore using switches where possible can reduce the number of potential bugs.

Example

❌ Bad:

void fn() {
  final Vehicle? value;

  if (value is Car || value is Truck) {} // LINT
  if (value case Car() || Truck()) {} // LINT
}

sealed class Vehicle {}

class Car extends Vehicle {}

class Truck implements Vehicle {
  const Truck();
}

✅ Good:

void fn() {
  final Vehicle? value;

  switch (value) {
    case Car():
      ...

    case Truck():
     ...
  }
}

sealed class Vehicle {}

class Car extends Vehicle {}

class Truck implements Vehicle {
  const Truck();
}

Example​

Example