TypeScript/tests/cases/compiler/partialTypeNarrowedToByTypeGuard.ts

26 lines
404 B
TypeScript

// @strict: true
type Obj = {} | undefined;
type User = {
email: string;
name: string;
};
type PartialUser = Partial<User>;
// type PartialUser = {
// email?: string;
// name?: string;
// };
function isUser(obj: Obj): obj is PartialUser {
return true;
}
function getUserName(obj: Obj) {
if (isUser(obj)) {
return obj.name;
}
return '';
}