# tiny-experiment

A lightweight utility to run split tests in your javascript application.

# Quick start

1) Install
```
npm install tiny-experiment --save
```

2) Require module
```
var tinyManager = require('tiny-experiment');
// window.tinyManager is available now

```

3) Register experiments once
```
tinyManager.setup({
  experiments: [
    {
      experimentKey(required): 'homepageButtonStyle', // unique key
      experimentName(required): 'Homepage button style', // descriptive name for analytics

      variantNames(required): ['blue', 'red'],
      variantWeights(optional): [0.25, 0.75], // must add up to 1.0

      cached(optional): Boolean // default false, if true user will see same variant next time
      cachePeriod(optional): Number // default 7, if cached user will see same variant for X days
    },
    {
      // experiment two
    }
  ]
})
```

4a) Then run an experiment with variant-specific handlers
```
var experiment = tinyManager.getExperiment('homepageButtonStyle')

experiment
.on('blue', function() {
  // make button blue
})
.on('red', function() {
  // make button red
})
.run()
```

4b) You can 'run' the experiment asynchronously
```
experiment.on('blue', function() { ... })

someAsyncFunction(function() {
  experiment.run()
})

// or reversed in order
```

# When an experiment is run

A segment analytics call is made with event name 'Experiment Viewed', and the properties: experimentName, variantName, variantId, and variantNames. Make your funnel with 'Experiment Viewed' (experimentName, variantName) as the start point and any other segment event as the endpoint. 

To customize the default behavior when an experiment is run:

```
import tinyManager from 'tiny-experiment';
tinyManager.setup({
  experiments: [ ...experiments... ],
  globalCompletionHandler: function(params) {
    // do something where argument, params, has keys: experimentName, variantName, variantId, and variantNames
  }
})
```

# Manual variant setting

```
http://domain.com/?experimentKey=homepageButtonStyle&variantName=blue || variantId=1
```

This will run the experiment with experimentKey = homepageButtonStyle, and manually set the variant as 'blue'

# Angular 

a directive that let's you hide/show elements without writing any javascript: https://github.com/genelee/angular-experiment