Stepper: bug that causes frontend crash

[martin-henz]

https://share.sourceacademy.nus.edu.sg/z6al6

The program that crashes the frontend:

function a() {
    if (true) {
        display(1);
        return 1;
    } else {
        undefined;
    }
}
a();

[teleohead]

Another example that has caused crash, which we discussed this morning. @martin-henz

It could be caused by any programmes involving the following error statement:

tail(null);

[teleohead]

I believe the frontend will clash as long as there is a TYPE ERROR of argument for head() and tail().

Situations are the same with the following statements:

head();
tail("");
head(undefined);
function foo() {}; tail(foo);
head("foo");

[martin-henz]

Got it. Thanks for the further details @teleohead