An A/B testing engine
On the 16th of March 2024 this repository will change ownership and move to the personal account of one of it’s maintainers, Yaniv Kessler
Ownership change will also occur on the npm registry to Yaniv Kessler
An A/B testing engine
To use this engine, create one or more experiments and stick them in a container. Each experiment is composed of a bunch of variations which are randomly picked/served to you. Once you obtain a variation, use it to render some content or make some sort of a decision.
The container’s job is to select the correct experiments for each visitor
based on each experiment’s targeting expression. Thusly, to get a variation one would call pick()
twice, once on the container and once on the experiment.
Further information about the targeting experssion syntax can be found here: pickpick-targeting-compiler
Also, please take a look at our examples
npm i -S pickpick
Let’s say we have a website with two pages buy
and index
and we want to run 3 experiments:
buy
page test color button
buy
page test price
index
page test text
const { Experiment, ExperimentContainer } = require('pickpick')
// first create the experiments:
let e1 = Experiment.create({
name: 'buy page button color experiment',
id: '953d6fe0',
variations: [
{ object: '#ff0000', weight: 4 },
{ object: '#ff0000', weight: 1 },
{ object: '#00ff00', weight: 1 }
],
targeting: '_.path in ["buy", "index"]'
})
let e2 = Experiment.create({
name: 'buy page price experiment',
id: 'a40f09ac',
variations: [
{ object: 25 },
{ object: 35 },
{ object: 45 }
],
targeting: '_.path !== "home" && page !== "foo"'
})
let e3 = Experiment.create({
name: 'index text experiment',
id: 'ac49ef42',
variations: [
{ object: 'hi' },
{ object: 'hello' },
{ object: 'welcome' }
],
targeting: '_.path === "index"'
})
// now create a container:
let experiments = [e1, e2, e3]
let container = ExperimentContainer.create({ experiments })
// simulate a visitor that needs a determination about which variation of which experiment he gets:
let visitor = { page: 'index' }
for (let i = 0; i < 10; i++) {
let experiment = container.pick(visitor)
if (!experiment) {
// no experiment that targets this user
// handle this with defaults
console.log('default goes here')
} else {
console.log(`selected experiment '${experiment.name}' for '${JSON.stringify(visitor)}'`)
let variation = experiment.pick()
console.log(`selected variation is ${variation}`)
}
}
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Experiment.js#L34-L171" title="Source code on GitHub">lib/Experiment.js:34-171
An A/B test experiment contains one or more @Variation">variations and a definition of @Targeting">targeting.
Experiments are serializable and can be created using classes from this engine or object literals. For example:
const { Experiment } = require('pickpick')
const e1 = Experiment.create({
name: 'my experiment',
id: 'foo',
variations: [
{ object: 1, weight: 1 },
{ object: 2, weight: 1 },
{ object: 3, weight: 1 }
],
targeting: '_.geo === "US"'
})
$0
Object $0.name
$0.id
$0.variations
(optional, default []
)$0.targeting
(optional, default Targeting.default()
)$0.userData
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Experiment.js#L66-L68" title="Source code on GitHub">lib/Experiment.js:66-68
randomly select one variation from the Variations set
Returns Variant the value contained within the selected variation
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Experiment.js#L76-L78" title="Source code on GitHub">lib/Experiment.js:76-78
check if this experiment matches the input targeting
targeting
Object Returns Boolean
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Experiment.js#L84-L95" title="Source code on GitHub">lib/Experiment.js:84-95
add another variation to this experiment
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Experiment.js#L116-L118" title="Source code on GitHub">lib/Experiment.js:116-118
iterate over the variations contained in this experiment
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Targeting.js#L11-L80" title="Source code on GitHub">lib/Targeting.js:11-80
Targeting
expression
String see pickpick-targeting-compiler for more detailsuserEnvironment
Object (optional, default {}
)git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Targeting.js#L31-L39" title="Source code on GitHub">lib/Targeting.js:31-39
check if the input data is matched by this targeting instance
inputTargeting
Object is normally a simple js objectReturns Boolean
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Targeting.js#L45-L47" title="Source code on GitHub">lib/Targeting.js:45-47
access this Targeting’s expression
Returns String
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Targeting.js#L52-L54" title="Source code on GitHub">lib/Targeting.js:52-54
iterate over the features that participate in the targeting
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Targeting.js#L61-L63" title="Source code on GitHub">lib/Targeting.js:61-63
check if a feature is part of this targeting instance
feature
String a name of a feature, e.g geo
Returns Boolean
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/Variation.js#L9-L99" title="Source code on GitHub">lib/Variation.js:9-99
A variation attaches weight to a piece of data. Variations are used in Experiments and ExperimentContainers
$0
Object $0.object
$0.weight
(optional, default 1
)git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L38-L239" title="Source code on GitHub">lib/ExperimentContainer.js:38-239
Contains one or more experiments and routes traffic evenly to each of them based on their
targeting. The following is an example of using a container to host several experiments, pick
on thats appropriate for a single visitor’s targeting and then access a variation from the
selected experiment:
const { ExperimentContainer, Experiment } = require('pickpick')
const experiments = [
Experiment.create(...),
Experiment.create(...),
Experiment.create(...)
]
const container = ExperimentContainer.create({ experiments })
let experiment = container.pick({ geo: 'US', page: 'index.html '})
if (experiment) {
let variation = experiment.pick()
// do something with the variation data
} else {
console.log('no experiments that match this targeting were found')
}
__seed
number just for testing / predictable engine resultsgit@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L77-L102" title="Source code on GitHub">lib/ExperimentContainer.js:77-102
Add an experiment to this container. Inside a container experiments must
have unique ids. This method can accept different kinds of experiment expressions:
container.add(Experiment.create(...))
```js
container.add(Variation.create(Experiment.create(...)))
````
container.add(Variation.create({... experiment data ...}))
container.add({ object: {... experiment data }, weight: 5 })
experiments
…any git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L131-L151" title="Source code on GitHub">lib/ExperimentContainer.js:131-151
The pick method accepts a targeting object and randomly selects an experiment
from a set of experiments that match the targeting specification.
By default, selection is random and even, however, bias can be applied by specifying a weight
when adding an experiment to the container (see ExperimentContainer.add())
Weights are considered at the moment of selection from the current set of
matching experiments, therefor, careful planning of targeting is required to achieve
accurate traffic distribution betwee experiments.
For example, consider two experiments, E1
, that targets { geo: 'US', page: '*' }
and E2
that targets
{ geo: 'US', page: 'index.html' }
. If both had the weight 1
, given the following stream
of visitors:
{ geo: 'US', page: 'sale.html' }
{ geo: 'US', page: 'index.html' }
{ geo: 'US', page: 'sale.html' }
{ geo: 'US', page: 'index.html' }
Then it is more likely that E1
will receive more traffic than E2
since E1
competes with E2
evenly on index.html
page but not on sale.html
targeting
Targeting Returns Experiment an experiment that matches this targeting or null if none is found.
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L159-L161" title="Source code on GitHub">lib/ExperimentContainer.js:159-161
An iterator over all the targeting features from all the experiments
added to this container
Returns Iterator
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L175-L177" title="Source code on GitHub">lib/ExperimentContainer.js:175-177
iterate over all the experiments in this container:
let container = ExperimentContainer.create(...)
for (let experiment of container) {
console.log(experiment.id)
}
Returns ObjectIterator
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L184-L188" title="Source code on GitHub">lib/ExperimentContainer.js:184-188
check if this container contains the specified experiment
experiment
Expriment Returns Boolean
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L195-L201" title="Source code on GitHub">lib/ExperimentContainer.js:195-201
check if this container contains an experiment using an id
experimentId
String Returns Boolean
git@github.com/:ReasonSoftware/pickpick/blob/a6938cd996f3f68216a96b210bf576e6e3ff6ece/lib/ExperimentContainer.js#L208-L215" title="Source code on GitHub">lib/ExperimentContainer.js:208-215
serialize this container with all it’s experiments
Returns Object