device_home/node_modules/p-locate/readme.md

   1 # p-locate [![Build Status](https://travis-ci.org/sindresorhus/p-locate.svg?branch=master)](https://travis-ci.org/sindresorhus/p-locate)
   2
   3 > Get the first fulfilled promise that satisfies the provided testing function
   4
   5 Think of it like an async version of [`Array#find`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/find).
   6
   7
   8 ## Install
   9
  10 ```
  11 $ npm install p-locate
  12 ```
  13
  14
  15 ## Usage
  16
  17 Here we find the first file that exists on disk, in array order.
  18
  19 ```js
  20 const pathExists = require('path-exists');
  21 const pLocate = require('p-locate');
  22
  23 const files = [
  24         'unicorn.png',
  25         'rainbow.png', // Only this one actually exists on disk
  26         'pony.png'
  27 ];
  28
  29 (async () => {
  30         const foundPath = await pLocate(files, file => pathExists(file));
  31
  32         console.log(foundPath);
  33         //=> 'rainbow'
  34 })();
  35 ```
  36
  37 *The above is just an example. Use [`locate-path`](https://github.com/sindresorhus/locate-path) if you need this.*
  38
  39
  40 ## API
  41
  42 ### pLocate(input, tester, [options])
  43
  44 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`.
  45
  46 #### input
  47
  48 Type: `Iterable<Promise|any>`
  49
  50 #### tester(element)
  51
  52 Type: `Function`
  53
  54 Expected to return a `Promise<boolean>` or boolean.
  55
  56 #### options
  57
  58 Type: `Object`
  59
  60 ##### concurrency
  61
  62 Type: `number`<br>
  63 Default: `Infinity`<br>
  64 Minimum: `1`
  65
  66 Number of concurrently pending promises returned by `tester`.
  67
  68 ##### preserveOrder
  69
  70 Type: `boolean`<br>
  71 Default: `true`
  72
  73 Preserve `input` order when searching.
  74
  75 Disable this to improve performance if you don't care about the order.
  76
  77
  78 ## Related
  79
  80 - [p-map](https://github.com/sindresorhus/p-map) - Map over promises concurrently
  81 - [p-filter](https://github.com/sindresorhus/p-filter) - Filter promises concurrently
  82 - [p-any](https://github.com/sindresorhus/p-any) - Wait for any promise to be fulfilled
  83 - [More…](https://github.com/sindresorhus/promise-fun)
  84
  85
  86 ## License
  87
  88 MIT © [Sindre Sorhus](https://sindresorhus.com)