Asynchronous code

[qwenger]

I have trouble getting asynchronous code (async/await, Promise's) to work. I tried several approaches without much luck:

ctx = quickjs.Context()

ctx.add_callable("print", print)

ctx.eval("""
async function a() {
    print(1 + await 1);
}

a();
""")

ctx.eval("""
Promise.resolve(3).then(
    r => print(r)
);
""")

f = quickjs.Function("f", """
var b = {};

async function a() {
    b.x = 1 + await 1;
}

a()

function f() {
    while (!b.x) {}
    return b.x;
}
""")

f()

The two first codes execute without printing anything. The third code hangs due to non-terminating busy waiting.

Note: the codes work correctly in qjs (quickjs' interactive prompt), of course replacing print with console.log in the first two examples.

[qwenger]

Note 2:

• marking a function async but without using an await works (though it is not very useful...):

var b = {};

async function a() {
    b.x = 1;
}

a();

while (!b.x) {} // does not hang

• Mozilla Firefox' console has the same issue, while Google Chrome's handles await and Promise's as expected. So do qjs and node. Busy-waiting hangs in all tested consoles, which is actually kind of expected because js is single-threaded.