Automagically switch your Node.js version
based on `package.json`
**nodengine** is an automatic way to switch your Node.js version per project reading `engines` fields at `package.json`.
It needs a global version manager as [n](https://www.npmjs.com/package/n) or [nvm](https://www.npmjs.com/package/nvm).
If you want know when a new version of node is released, follow our [@nodengine](https://twitter.com/nodengine) bot.
## Install
```bash
$ npm install nodengine --global --production
```
## Usage
Set the desired version range in the `package.json`
```json
"engines": {
"node": ">= 0.10"
}
```
Then just run `nodengine` to change the current node version to version declared into `package.json`.
It will use the highest version that satisfies the range.
## Automatic switching
Enabling automatic switching consist in a little shell script for check if `package.json` exists and then runs `nodengine`.
Add the follow snippet in a file loaded by your shell agent, for example, `.extra`.
```bash
function chpwd() {
local PKG
PKG=$PWD/package.json
if [ -f "$PKG" ] && [ "$NODENGINE_LAST_DIR" != "$PWD" ]; then
nodengine
printf "\033[36m%s\033[0m \033[90m%s\033[0m\n" "nodengine" "$(node --version)"
NODENGINE_LAST_DIR=$PWD
fi
}
function cd() { builtin cd "$@" && chpwd; }
function pushd() { builtin pushd "$@" && chpwd; }
function popd() { builtin popd "$@" && chpwd; }
```
## Fetching new versions
The program use a local cache for avoid fetching versions of node all the time.
By default, new versions of node will be fetched after 5 days.
You can setup the interval using `NODENGINE_INTERVAL`
For example, if you want to fetch all versions every time that you run the program:
```bash
NODENGINE_INTERVAL=0 nodengine
```
## License
MIT © [Kiko Beats](http://kikobeats.com)