[d565449] | 1 | # p-locate [![Build Status](https://travis-ci.com/sindresorhus/p-locate.svg?branch=master)](https://travis-ci.com/github/sindresorhus/p-locate)
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| 2 |
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| 3 | > Get the first fulfilled promise that satisfies the provided testing function
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| 4 |
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| 5 | Think of it like an async version of [`Array#find`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/find).
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| 6 |
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| 7 | ## Install
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| 8 |
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| 9 | ```
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| 10 | $ npm install p-locate
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| 11 | ```
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| 12 |
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| 13 | ## Usage
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| 14 |
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| 15 | Here we find the first file that exists on disk, in array order.
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| 16 |
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| 17 | ```js
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| 18 | const pathExists = require('path-exists');
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| 19 | const pLocate = require('p-locate');
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| 20 |
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| 21 | const files = [
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| 22 | 'unicorn.png',
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| 23 | 'rainbow.png', // Only this one actually exists on disk
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| 24 | 'pony.png'
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| 25 | ];
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| 26 |
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| 27 | (async () => {
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| 28 | const foundPath = await pLocate(files, file => pathExists(file));
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| 29 |
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| 30 | console.log(foundPath);
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| 31 | //=> 'rainbow'
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| 32 | })();
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| 33 | ```
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| 34 |
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| 35 | *The above is just an example. Use [`locate-path`](https://github.com/sindresorhus/locate-path) if you need this.*
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| 36 |
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| 37 | ## API
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| 38 |
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| 39 | ### pLocate(input, tester, options?)
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| 40 |
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| 41 | Returns a `Promise` that is fulfilled when `tester` resolves to `true` or the iterable is done, or rejects if any of the promises reject. The fulfilled value is the current iterable value or `undefined` if `tester` never resolved to `true`.
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| 42 |
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| 43 | #### input
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| 44 |
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| 45 | Type: `Iterable<Promise | unknown>`
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| 46 |
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| 47 | An iterable of promises/values to test.
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| 48 |
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| 49 | #### tester(element)
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| 50 |
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| 51 | Type: `Function`
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| 52 |
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| 53 | This function will receive resolved values from `input` and is expected to return a `Promise<boolean>` or `boolean`.
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| 54 |
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| 55 | #### options
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| 56 |
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| 57 | Type: `object`
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| 58 |
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| 59 | ##### concurrency
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| 60 |
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| 61 | Type: `number`\
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| 62 | Default: `Infinity`\
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| 63 | Minimum: `1`
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| 64 |
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| 65 | Number of concurrently pending promises returned by `tester`.
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| 66 |
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| 67 | ##### preserveOrder
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| 68 |
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| 69 | Type: `boolean`\
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| 70 | Default: `true`
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| 71 |
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| 72 | Preserve `input` order when searching.
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| 73 |
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| 74 | Disable this to improve performance if you don't care about the order.
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| 75 |
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| 76 | ## Related
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| 77 |
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| 78 | - [p-map](https://github.com/sindresorhus/p-map) - Map over promises concurrently
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| 79 | - [p-filter](https://github.com/sindresorhus/p-filter) - Filter promises concurrently
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| 80 | - [p-any](https://github.com/sindresorhus/p-any) - Wait for any promise to be fulfilled
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| 81 | - [More…](https://github.com/sindresorhus/promise-fun)
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| 82 |
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| 83 | ---
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| 84 |
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| 85 | <div align="center">
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| 86 | <b>
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| 87 | <a href="https://tidelift.com/subscription/pkg/npm-p-locate?utm_source=npm-p-locate&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
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| 88 | </b>
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| 89 | <br>
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| 90 | <sub>
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| 91 | Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
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| 92 | </sub>
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| 93 | </div>
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