/
waitForPredicatePageFunction.js
83 lines (78 loc) · 2.32 KB
/
waitForPredicatePageFunction.js
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async function waitForPredicatePageFunction(predicateBody, polling, timeout, ...args) {
const predicate = new Function('...args', predicateBody);
let timedOut = false;
if (timeout)
setTimeout(() => (timedOut = true), timeout);
if (polling === 'raf')
return await pollRaf();
if (polling === 'mutation')
return await pollMutation();
if (typeof polling === 'number')
return await pollInterval(polling);
/**
* @returns {!Promise<*>}
*/
async function pollMutation() {
const success = await predicate(...args);
if (success)
return Promise.resolve(success);
let fulfill;
const result = new Promise((x) => (fulfill = x));
const observer = new MutationObserver(async () => {
if (timedOut) {
observer.disconnect();
fulfill();
}
const success = await predicate(...args);
if (success) {
observer.disconnect();
fulfill(success);
}
});
observer.observe(document, {
childList: true,
subtree: true,
attributes: true,
});
if (timeout)
setTimeout(() => {
observer.disconnect();
fulfill();
}, timeout);
return result;
}
async function pollRaf() {
let fulfill;
const result = new Promise((x) => (fulfill = x));
await onRaf();
return result;
async function onRaf() {
if (timedOut) {
fulfill();
return;
}
const success = await predicate(...args);
if (success)
fulfill(success);
else
requestAnimationFrame(onRaf);
}
}
async function pollInterval(pollInterval) {
let fulfill;
const result = new Promise((x) => (fulfill = x));
await onTimeout();
return result;
async function onTimeout() {
if (timedOut) {
fulfill();
return;
}
const success = await predicate(...args);
if (success)
fulfill(success);
else
setTimeout(onTimeout, pollInterval);
}
}
}