/
asyncWaterfall.ts
57 lines (55 loc) · 1.39 KB
/
asyncWaterfall.ts
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/**
* In series, run an array of `async` functions
*
* without arguments
* ```js
* let sleepyFunc = async () => {
* await new Promise((resolve) => { setTimeout(resolve, 100) })
* return (new Date()).getTime()
* }
* let jobs = [sleepyFunc, sleepyFunc, sleepyFunc]
* let responses = await api.utils.asyncWaterfall(jobs)
* // responses = [1506536188356, 1506536188456, 1506536188456]
* ```
*
* with arguments
* ```js
* let sleepyFunc = async (response) => {
* await new Promise((resolve) => { setTimeout(resolve, 100) })
* return response
* }
* let jobs = [
* {method: sleepyFunc, args: ['a']},
* {method: sleepyFunc, args: ['b']},
* {method: sleepyFunc, args: ['c']}
* ]
* let responses = await api.utils.asyncWaterfall(jobs)
* // responses = ['a', 'b', 'c']
* ```
*/
export async function asyncWaterfall(
jobs: Array<Function | { method: Function; args: Array<any> }>
): Promise<Array<any>> {
const results = [];
while (jobs.length > 0) {
const collection = jobs.shift();
let job;
let args;
if (typeof collection === "function") {
job = collection;
args = [];
} else {
job = collection.method;
args = collection.args;
}
const value = await job.apply(this, args);
results.push(value);
}
if (results.length === 0) {
return null;
}
if (results.length === 1) {
return results[0];
}
return results;
}