=== tests/cases/compiler/assertionFunctionsCanNarrowByDiscriminant.ts ===
interface Cat {
>Cat : Symbol(Cat, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 0, 0))

    type: 'cat';
>type : Symbol(Cat.type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 0, 15))

    canMeow: true;
>canMeow : Symbol(Cat.canMeow, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 1, 16))
}

interface Dog {
>Dog : Symbol(Dog, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 3, 1))

    type: 'dog';
>type : Symbol(Dog.type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 5, 15))

    canBark: true;
>canBark : Symbol(Dog.canBark, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 6, 16))
}

type Animal = Cat | Dog;
>Animal : Symbol(Animal, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 8, 1))
>Cat : Symbol(Cat, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 0, 0))
>Dog : Symbol(Dog, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 3, 1))

declare function assertEqual<T>(value: any, type: T): asserts value is T;
>assertEqual : Symbol(assertEqual, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 10, 24))
>T : Symbol(T, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 12, 29))
>value : Symbol(value, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 12, 32))
>type : Symbol(type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 12, 43))
>T : Symbol(T, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 12, 29))
>value : Symbol(value, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 12, 32))
>T : Symbol(T, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 12, 29))

const animal = { type: 'cat', canMeow: true } as Animal;
>animal : Symbol(animal, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 14, 5))
>type : Symbol(type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 14, 16))
>canMeow : Symbol(canMeow, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 14, 29))
>Animal : Symbol(Animal, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 8, 1))

assertEqual(animal.type, 'cat' as const);
>assertEqual : Symbol(assertEqual, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 10, 24))
>animal.type : Symbol(type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 0, 15), Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 5, 15))
>animal : Symbol(animal, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 14, 5))
>type : Symbol(type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 0, 15), Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 5, 15))
>const : Symbol(const)

animal.canMeow; // since is cat, should not be an error
>animal.canMeow : Symbol(Cat.canMeow, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 1, 16))
>animal : Symbol(animal, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 14, 5))
>canMeow : Symbol(Cat.canMeow, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 1, 16))

const animalOrUndef = { type: 'cat', canMeow: true } as Animal | undefined;
>animalOrUndef : Symbol(animalOrUndef, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 19, 5))
>type : Symbol(type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 19, 23))
>canMeow : Symbol(canMeow, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 19, 36))
>Animal : Symbol(Animal, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 8, 1))

assertEqual(animalOrUndef?.type, 'cat' as const);
>assertEqual : Symbol(assertEqual, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 10, 24))
>animalOrUndef?.type : Symbol(type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 0, 15), Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 5, 15))
>animalOrUndef : Symbol(animalOrUndef, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 19, 5))
>type : Symbol(type, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 0, 15), Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 5, 15))
>const : Symbol(const)

animalOrUndef.canMeow; // since is cat, should not be an error
>animalOrUndef.canMeow : Symbol(Cat.canMeow, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 1, 16))
>animalOrUndef : Symbol(animalOrUndef, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 19, 5))
>canMeow : Symbol(Cat.canMeow, Decl(assertionFunctionsCanNarrowByDiscriminant.ts, 1, 16))