blob: 1528a00c9f5db2eac4a2c5888a0f43f6f428bcb3 [file] [log] [blame]
// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/**
* @fileoverview Manages the current user's participation in experiments (e.g.
* phased rollouts).
*
* This file is an early prototype serving the needs of go/monorail-slo-v0.
*
* The more mature design is under discussion:
* http://doc/1rtYXq68WSlTNCzVJiSttLWF14CiK5sOlEef2JWAgheg
*/
/**
* An Enum representing known expreriments.
*
* @typedef {string} Experiment
*/
/**
* @type {Experiment}
*/
export const SLO_EXPERIMENT = 'slo';
const EXPERIMENT_QUERY_PARAM = 'e';
const DISABLED_STR = '-';
const _SLO_EXPERIMENT_USER_DISPLAY_NAMES = new Set([
'jessan@google.com',
]);
/**
* Checks whether the current user is in given experiment.
*
* @param {Experiment} experiment The experiment to check.
* @param {UserV0=} user The current user. Although any user can currently
* be passed in, we only intend to support checking if the current user is
* in the experiment. In the future the user parameter may be removed.
* @param {Object} queryParams The current query parameters, parsed by qs.
* We support a string like 'e=-exp1,-exp2...' for disabling experiments.
*
* We allow disabling so that a user in the fishfood group can work around
* any bugs or undesired behaviors the experiment may introduce for them.
*
* As of now, we don't allow enabling experiments by override params.
* We may not want access shared beyond the fishfood group (e.g. if it is a
* feature we are likely to change dramatically or take away).
* @return {boolean} Whether the experiment is enabled for the current user.
*/
export const isExperimentEnabled = (experiment, user, queryParams) => {
const experimentOverrides = parseExperimentParam(
queryParams[EXPERIMENT_QUERY_PARAM]);
if (experimentOverrides[experiment] === false) {
return false;
}
switch (experiment) {
case SLO_EXPERIMENT:
return !!user &&
_SLO_EXPERIMENT_USER_DISPLAY_NAMES.has(user.displayName);
default:
throw Error('Unknown experiment provided');
}
};
/**
* Parses a comma separated list of experiments from the query string.
* Experiment strings preceded by DISABLED_STR are overrode to be disabled,
* otherwise they are to be enabled.
*
* Does not do any validation of the experiment string provided.
*
* @param {string?} experimentParam comma separated experiements.
* @return {Object} Maps experiment name to whether enabled or
* disabled boolean. May include invalid experiment names.
*/
const parseExperimentParam = (experimentParam) => {
const experimentOverrides = {};
if (experimentParam) {
for (const experimentOverride of experimentParam.split(',')) {
if (experimentOverride.startsWith(DISABLED_STR)) {
const experiment = experimentOverride.substr(DISABLED_STR.length);
experimentOverrides[experiment] = false;
} else {
experimentOverrides[experimentOverride] = true;
}
}
}
return experimentOverrides;
};