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// Without the pref, resolve(thenable, true) must behave exactly like
// resolve(thenable) — the second argument is ignored, and Get("then") runs
// on the caller's stack.
// resolve.length is 1 in the pref-off (default) configuration.
{
const {resolve} = Promise.withResolvers();
assertEq(resolve.length, 1,
"without the pref, resolve.length should be 1 (current spec)");
}
// resolve(thenable, true) with the pref off reads 'then' synchronously.
{
let getterCalls = 0;
const thenable = {
get then() {
getterCalls++;
return undefined;
},
};
const {promise, resolve} = Promise.withResolvers();
resolve(thenable, true);
assertEq(getterCalls, 1,
"without the pref, the second arg is ignored and 'then' is read sync");
drainJobQueue();
}
// The proxy trap also fires synchronously.
{
const trapCalls = [];
const thenable = new Proxy({}, {
get(_t, name) {
trapCalls.push(String(name));
return undefined;
},
});
const {promise, resolve} = Promise.withResolvers();
resolve(thenable, true);
assertEq(trapCalls.length, 1,
"without the pref, proxy 'get' trap for 'then' fires synchronously");
assertEq(trapCalls[0], "then");
drainJobQueue();
}