Source code
Revision control
Copy as Markdown
Other Tools
// |jit-test| --fast-warmup; --no-threads
// Test |using| and |await using| spanning a suspend.
let log = [];
function* syncUsing() {
using res = { [Symbol.dispose]() { log.push("dispose"); } };
log.push("a");
yield 1;
log.push("b");
return "end";
}
// The async disposal itself awaits, so it suspends the generator again.
async function* asyncUsing() {
await using res = {
[Symbol.asyncDispose]() { log.push("dispose"); return Promise.resolve(); }
};
log.push("a");
yield 1;
log.push("b");
return "end";
}
// One disposable per iteration, so a forced return mid-loop has a live resource.
function disposables(n) {
let i = 0;
return {
[Symbol.iterator]() { return this; },
next() {
if (i >= n) {
return { done: true };
}
const tag = i++;
return {
value: {
[Symbol.asyncDispose]() {
log.push("d" + tag);
return Promise.resolve();
}
},
done: false
};
}
};
}
async function* forAwaitUsing(n) {
for (await using res of disposables(n)) {
yield "y";
}
return "end";
}
for (let i = 0; i < 200; i++) {
log = [];
const g = syncUsing();
assertEq(g.next().value, 1);
const r = g.next();
assertEq(r.done, true);
assertEq(r.value, "end");
assertEq(log.join(","), "a,b,dispose");
}
for (let i = 0; i < 200; i++) {
log = [];
const g = syncUsing();
assertEq(g.next().value, 1);
const r = g.return("stop");
assertEq(r.done, true);
assertEq(r.value, "stop");
assertEq(log.join(","), "a,dispose");
}
let failure = null;
(async function () {
for (let i = 0; i < 200; i++) {
log = [];
const g = asyncUsing();
assertEq((await g.next()).value, 1);
const r = await g.next();
assertEq(r.done, true);
assertEq(r.value, "end");
assertEq(log.join(","), "a,b,dispose");
}
for (let i = 0; i < 200; i++) {
log = [];
const g = asyncUsing();
assertEq((await g.next()).value, 1);
const r = await g.return("stop");
assertEq(r.done, true);
assertEq(r.value, "stop");
assertEq(log.join(","), "a,dispose");
}
for (let i = 0; i < 200; i++) {
log = [];
const g = forAwaitUsing(3);
assertEq((await g.next()).value, "y");
const r = await g.return("stop");
assertEq(r.done, true);
assertEq(r.value, "stop");
assertEq(log.join(","), "d0");
}
})().catch(e => { failure = e; });
drainJobQueue();
assertEq(failure, null);