Repeat until the predicate returns true and resolves a Promise
npm install repeat-until-asyncRepeats the async function The library provides TypeScript definitions. No dependencies needed. Please be sure that your environment has Promise support (or has a polyfill).
``sh`
$ npm install repeat-until-async
The simple use case is described below:
`javascript
const repeatUntil = require('repeat-until-async');
const timeOfStart = Date.now();
// Wait for some async operation to end
repeatUntil(() => {
const timePassed = Date.now() - timeOfStart;
return (timePassed < 500)
&& (timePassed % 2 === 0) // Some random stuff
? true
: throw new Error('Async operation failed');
}, 600)
.then((result) => {
// Here are the operations to be done after predicate
console.log('Async operation succeeded, predicate result = ', result);
})
.catch((error) => {
// Here are the operations to be done if predicate didn't succeed in the timeout
console.log('Async operation failed: ', error);
});
`
The library is async/await compatible because it uses Promises/A+, so the example above could be rewritten:
`javascript
const repeatUntil = require('repeat-until-async');
const timeOfStart = Date.now();
// Wait for some async operation to end
try {
const result = await repeatUntil(() => {
const timePassed = Date.now() - timeOfStart;
return (timePassed < 500)
&& (timePassed % 2 === 0) // Some random stuff
? true
: throw new Error('Async operation failed');
}, 600);
// Here are the operations to be done after predicate
console.log('Async operation succeeded, predicate result = ', result);
} catch (error) {
// Here are the operations to be done if predicate didn't succeed in the timeout
console.log('Async operation failed: ', error);
}
`
`javascript``
/**
* Waits for predicate to be truthy and resolves a Promise
*
* @param predicate Function Predicate that checks the condition
* @param timeout Number Maximum wait interval, optional, 5000ms by default
* @param interval Number Wait interval, optional, 50ms by default
* @return Promise Promise to return a callback result
*/
function repeatUntil(
predicate: Function,
timeout: Number = 5000,
interval: Number = 50
): Promise;
No building required, library is implemented with ES5 for better compatibility and shipped as is.
Library is shipped "as is" under MIT License.
Feel free to contribute. Just raise ann issue, create a pull request covering it and don't forget to test everything properly.