JarCastingp-each-series 
Iterate over promises serially
Useful as a side-effect iterator. Prefer p-map if you don't need side-effects, as it's concurrent.
Install
$ npm install p-each-series
Usage
const pEachSeries = require('p-each-series');
const keywords = [
getTopKeyword(), //=> Promise
'rainbow',
'pony'
];
const iterator = async element => saveToDiskPromise(element);
(async () => {
console.log(await pEachSeries(keywords, iterator));
//=> ['unicorn', 'rainbow', 'pony']
})();
API
pEachSeries(input, iterator)
Returns a Promise that is fulfilled when all promises in input and ones returned from iterator are fulfilled, or rejects if any of the promises reject. The fulfillment value is the original input.
input
Type: Iterable<Promise | unknown>
Iterated over serially in the iterator function.
iterator(element, index)
Type: Function
Return value is ignored unless it's Promise, then it's awaited before continuing with the next iteration.
pEachSeries.stop
Stop iterating through items by returning pEachSeries.stop from the iterator function.
const pEachSeries = require('p-each-series');
// Logs `a` and `b`.
const result = await pEachSeries(['a', 'b', 'c'], value => {
console.log(value);
if (value === 'b') {
return pEachSeries.stop;
}
});
console.log(result);
//=> ['a', 'b', 'c']
Related
- p-map-series - Map over promises serially
- p-series - Run promise-returning & async functions in series
- p-pipe - Compose promise-returning & async functions into a reusable pipeline
- p-waterfall - Run promise-returning & async functions in series, each passing its result to the next
- p-reduce - Reduce a list of values using promises into a promise for a value
- p-map - Map over promises concurrently
- More…