jnpf-web-datareport-v6x/node_modules/.pnpm-store/v3/files/6e/3f54cce608ff8b2d8e566498fe76dcacd7d64eed781b54ad916bdbea18ff41d01a37e0de9049c6066e7a1f85a270f2e9ce96fa160c198916cdd1d29557bef2

# invariant

[![Build Status](https://travis-ci.org/zertosh/invariant.svg?branch=master)](https://travis-ci.org/zertosh/invariant)

A mirror of Facebook's `invariant` (e.g. [React](https://github.com/facebook/react/blob/v0.13.3/src/vendor/core/invariant.js), [flux](https://github.com/facebook/flux/blob/2.0.2/src/invariant.js)).

A way to provide descriptive errors in development but generic errors in production.

## Install

With [npm](http://npmjs.org) do:

```sh
npm install invariant
```

## `invariant(condition, message)`

```js
var invariant = require('invariant');

invariant(someTruthyVal, 'This will not throw');
// No errors

invariant(someFalseyVal, 'This will throw an error with this message');
// Error: Invariant Violation: This will throw an error with this message
```

**Note:** When `process.env.NODE_ENV` is not `production`, the message is required. If omitted, `invariant` will throw regardless of the truthiness of the condition. When `process.env.NODE_ENV` is `production`, the message is optional – so they can be minified away.

### Browser

When used with [browserify](https://github.com/substack/node-browserify), it'll use `browser.js` (instead of `invariant.js`) and the [envify](https://github.com/hughsk/envify) transform will inline the value of `process.env.NODE_ENV`.

### Node

The node version is optimized around the performance implications of accessing `process.env`. The value of `process.env.NODE_ENV` is cached, and repeatedly used instead of reading `process.env`. See [Server rendering is slower with npm react #812](https://github.com/facebook/react/issues/812)