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// @strict: true
interface Cat {
type: 'cat';
canMeow: true;
}
interface Dog {
type: 'dog';
canBark: true;
}
type Animal = Cat | Dog;
declare function assertEqual<T>(value: any, type: T): asserts value is T;
const animal = { type: 'cat', canMeow: true } as Animal;
assertEqual(animal.type, 'cat' as const);
animal.canMeow; // since is cat, should not be an error
const animalOrUndef = { type: 'cat', canMeow: true } as Animal | undefined;
assertEqual(animalOrUndef?.type, 'cat' as const);
animalOrUndef.canMeow; // since is cat, should not be an error
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