Closed
Description
TypeScript Version: 2.0.3
Code
class Result1 {
readonly value1: number;
constructor(value1: number) {
this.value1 = value1;
}
}
class Result2 {
readonly value1: number;
readonly value2: number;
constructor(value1: number, value2: number) {
this.value1 = value1;
this.value2 = value2;
}
}
function someFunction(result: Result1 | Result2) {
if (result instanceof Result1) {
// result is still Result1 | Result2
console.log("1");
}
else {
// result is never ! this is wrong !
console.log("2");
}
}
// this will output 2 !
someFunction(new Result2(9,9))Expected behavior:
instance of type guard should not care about type compatibility
Actual behavior:
Wrong assertion by the compiler.