mediawiki-skins-MinervaNeue/resources/skins.minerva.scripts/AB.js
Stephen Niedzielski 672df850cb Hygiene: revise A/B test terminology
Improve the comments and APIs provided by AB.js:

- Control becomes unsampled.
- A becomes control.
- B becomes treatment.

This code does not appear to be in use presently, so it's a great time
to change it.

Change-Id: I31d619f889ee45102a4aed774a6ec41f0d95ba7d
2019-01-08 15:08:50 +00:00

78 lines
2.4 KiB
JavaScript

/*
* Bucketing wrapper for creating AB-tests.
*
* Given a test name, sampling rate, and session ID, provides a class that buckets a user into
* a predefined bucket ("unsampled", "control", or "treatment") and starts an AB-test.
*/
( function ( M, mwExperiments ) {
var bucket = {
UNSAMPLED: 'unsampled', // Old treatment: not sampled and not instrumented.
CONTROL: 'control', // Old treatment: sampled and instrumented.
TREATMENT: 'treatment' // New treatment: sampled and instrumented.
};
/**
* Buckets users based on params and exposes an `isSampled` and `getBucket` method.
* @param {Object} config Configuration object for AB test.
* @param {string} config.testName
* @param {number} config.samplingRate Sampling rate for the AB-test.
* @param {number} config.sessionId Session ID for user bucketing.
* @constructor
*/
function AB( config ) {
var
testName = config.testName,
samplingRate = config.samplingRate,
sessionId = config.sessionId,
test = {
name: testName,
enabled: !!samplingRate,
buckets: {
unsampled: 1 - samplingRate,
control: samplingRate / 2,
treatment: samplingRate / 2
}
};
/**
* Gets the users AB-test bucket.
*
* A boolean instead of an enum is usually a code smell. However, the nature of A/B testing
* is to compare an A group's performance to a B group's so a boolean seems natural, even
* in the long term, and preferable to showing bucketing encoding ("unsampled", "control",
* "treatment") to callers which is necessary if getBucket(). The downside is that now two
* functions exist where one would suffice.
*
* @return {string} AB-test bucket, `bucket.UNSAMPLED` by default, `bucket.CONTROL` or
* `bucket.TREATMENT` buckets otherwise.
*/
function getBucket() {
return mwExperiments.getBucket( test, sessionId );
}
function isControl() {
return getBucket() === bucket.CONTROL;
}
function isTreatment() {
return getBucket() === bucket.TREATMENT;
}
/**
* Checks whether or not a user is in the AB-test,
* @return {boolean}
*/
function isSampled() {
return getBucket() !== bucket.UNSAMPLED; // I.e., `isControl() || isTreatment()`
}
return {
isControl: isControl,
isTreatment: isTreatment,
isSampled: isSampled
};
}
M.define( 'skins.minerva.scripts/AB', AB );
}( mw.mobileFrontend, mw.experiments ) );