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30-seconds-of-code/snippets/runPromisesInSeries.md
Stefan Feješ 94bf2d2824 Fix test cases
2017-12-17 22:26:07 +01:00

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### runPromisesInSeries
Runs an array of promises in series.
Use `Array.reduce()` to create a promise chain, where each promise returns the next promise when resolved.
```js
const runPromisesInSeries = ps => ps.reduce((p, next) => p.then(next), Promise.resolve());
// const delay = (d) => new Promise(r => setTimeout(r, d))
// runPromisesInSeries([() => delay(1000), () => delay(2000)]) -> executes each promise sequentially, taking a total of 3 seconds to complete
```