# on-change

[![npm](https://img.shields.io/npm/dw/@olegjs/on-change)](https://www.npmjs.com/package/@olegjs/on-change)
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CLI tool to run a command if file has changed since the last time that command
was run.

Forgetting to run `npm i` or `npm ci` every time after `git pull` or switching
between branches and getting `Error: Cannot find module...`? Add the following
to `package.json` to automate this chore.

```json
"scripts": {
  "prestart": "npx @olegjs/on-change --file package-lock.json npm ci"
}
```

This CLI tool stores a file checksum in a hidden `sha` file every time it run a
given command. Made to automate running `npm ci` after pulling modified
`package-lock.json`.

## Install

```sh
npm install --save-dev @olegjs/on-change
```

## Usage

```sh
npx @olegjs/on-change --help

# Usage: on-change --file [file] [command]
#
# Options:
#   --help      Show help                                                [boolean]
#   --version   Show version number                                      [boolean]
#   --file, -f  Path to file to check for changes              [string] [required]
#   --color     Force color or disable with --no-color                   [boolean]
#
# Examples:
#   on-change --file package-lock.json npm    Reinstall dependencies on changed
#   ci                                        package-lock.json
```