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//// [narrowingIntersection.ts]
// Somehow this being an intersection matters.
type FooAndBaz = { foo: unknown } & { baz: unknown };
type Disjoint =
| { readonly value: string; readonly err?: never; }
| { readonly value?: never; readonly err: FooAndBaz; };
function test1(result: Disjoint): string {
if (result.err) {
throw result.err;
}
// Error, should OK
return result.value;
}
type TrivialIntersection = { a: 1 } & { a: 1 };
function want0(x: 0) {}
function test2(a: 0 | TrivialIntersection) {
if (a === 0) {
want0(a); // Fails, but expect to work
}
}
//// [narrowingIntersection.js]
function test1(result) {
if (result.err) {
throw result.err;
}
// Error, should OK
return result.value;
}
function want0(x) { }
function test2(a) {
if (a === 0) {
want0(a); // Fails, but expect to work
}
}
|
