mirror of
https://github.com/jerryscript-project/jerryscript.git
synced 2025-12-15 16:29:21 +00:00
74 lines
2.2 KiB
Markdown
74 lines
2.2 KiB
Markdown
# Converting incompatible features with Babel
|
|
To run ES6 sources with JerryScript that use unsupported language features, you can use Babel to transpile your code, which will output a semantically equivalent source file, where the unsupported features are replaced with ES5.1 code.
|
|
Babel is a JavaScript compiler that is used to convert ES2015+ code into a backward-compatible version. You can find more information [here](https://babeljs.io/).
|
|
|
|
## Example
|
|
|
|
```javascript
|
|
//Before
|
|
const fn = () => 1;
|
|
|
|
//After conversion
|
|
|
|
var fn = function fn() {
|
|
return 1;
|
|
};
|
|
```
|
|
## Table of Contents
|
|
* **[Getting ready](#getting-ready)**
|
|
* Installing node.js and npm
|
|
* **[Using babel](#using-babel)**
|
|
* **[Missing features/Polyfill](#missing-features)**
|
|
|
|
## Getting ready [](#getting-ready)
|
|
|
|
### 1. **Node.js and npm**
|
|
|
|
Start by updating the packages with
|
|
|
|
`$ sudo apt update`
|
|
|
|
Install `nodejs` using the apt package manager
|
|
|
|
`$ sudo apt install nodejs`
|
|
|
|
Check the version of **node.js** to verify that it installed
|
|
|
|
```bash
|
|
$ nodejs --version
|
|
Output: v8.10.0
|
|
```
|
|
|
|
Next up is installing **npm** with the following command
|
|
|
|
`$ sudo apt install npm`
|
|
|
|
Verify installation by typing:
|
|
|
|
```bash
|
|
$ npm --version
|
|
Output: 6.10.2
|
|
```
|
|
|
|
### 2. Using babel [](#using-babel)
|
|
|
|
Assuming you're in the tools/babel folder,
|
|
|
|
`$ sudo npm install`
|
|
|
|
After installing the dependencies it is ready to use.
|
|
|
|
Place the files/directories you want transpiled to the babel folder and run
|
|
|
|
`$ npm run transpile [name of input file/directory] [(OPTIONAL)name of output file/directory]`
|
|
|
|
If you want to use the same name, then only give the name once.
|
|
|
|
#### Missing features/Polyfill [](#missing-features)
|
|
Some features aren't implemented yet and found no babel plug-in for them.
|
|
|
|
* [Array.from](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from)
|
|
* [Array.prototype.fill](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/fill)
|
|
* [String.prototype.codePointAt](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/codePointAt)
|
|
|
|
In the case you encounter those, use the polyfill found on the linked sites. Also, **be aware** there could be more. |