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63 lines
1.5 KiB
Markdown
63 lines
1.5 KiB
Markdown
**NOTE:** Starting from Node.js v.8.0.0, the promisify method is now included in the `util` native library.
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On Node.js, the usage of the native method is recommended!
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```
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// Native promisify example
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const util = require('util');
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const readfile = util.promisify(fs.readFile);
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```
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# ES6 Promisify
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## This is a library to promisify callback-style functions to ES6 promises. You can also use it on the client-side.
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### Install it with:
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npm i --save promisify-es6
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or
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git clone https://github.com/manuel-di-iorio/promisify-es6.git
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### Example:
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```javascript
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var promisify = require("promisify-es6");
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var fs = require("fs");
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var readFile = promisify(fs.readFile);
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readFile("test.js")
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.then(function(content) {
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console.log(content.toString());
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})
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.catch(function(err) {
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console.error(err);
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});
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```
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A promisified function is still callable with the callback style:
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```javascript
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readFile("test.js", function(err, content) { //etc...
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```
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You can even promisify entire modules or arrays:
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```javascript
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var readFile = promisify(require("fs")).readFile;
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```
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## API
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```javascript
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promisify(method[, options])
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```
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*Method* can be a function or an array/map of functions to promisify
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*Options* can have the following properties:
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`context`: The context which to apply the called function (by default is the function itself)
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`replace`: When an array/map is passed and this is truthy, it will replace the original object
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### Test with Mocha:
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npm test
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