cypress-ld-control
v1.13.0
Published
Set LaunchDarkly feature flags from Cypress tests
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cypress-ld-control
Set LaunchDarkly feature flags from Cypress tests
Read the blog post Control LaunchDarkly From Cypress Tests.
Install
Add this plugin as a dev dependency
# install using NPM
$ npm i -D cypress-ld-control
# install using Yarn
$ yarn add -D cypress-ld-control
Most common use case: using this plugin from Cypress
Add the plugin to your Node-side plugins or config file
// cypress.config.js
// https://github.com/bahmutov/cypress-ld-control
const { initCypress } = require('cypress-ld-control')
...
e2e: {
setupNodeEvents(on, config) {
initCypress(on, config)
// IMPORTANT: return the updated config object
return config
},
}
If you want custom cy
commands to fetch or control the feature flags, include the plugin's commands file from your support file or from your spec file:
// your support or spec file
// https://github.com/bahmutov/cypress-ld-control
import 'cypress-ld-control/commands'
API
Commands
From the spec or browser support file you can import the cypress-ld-control/commands
module to add utility commands
isLaunchDarklyControlInitialized
Static, chained off Cypress
if (Cypress.isLaunchDarklyControlInitialized()) {
// we can control the LaunchDarkly flags
}
getFeatureFlag
cy.getFeatureFlag(featureFlagKey).then(flag => ...)
setFeatureFlagForUser
cy.setFeatureFlagForUser(featureFlagKey, userId, variationIndex)
removeUserTarget
cy.removeUserTarget(featureFlagKey, userId)
Plugin Node API
This plugin provides the following functions
getFeatureFlags
Returns all feature flags. Warning: could be a lot of flags!
const flags = await ldApi.getFeatureFlags()
// flags is an array of objects
getFeatureFlag
Returns a large object with everything there is two know about the feature flag in a particular environment
const flag = ldApi.getFeatureFlag('my-feature-flag')
setFeatureFlagForUser
Important: the feature flag must have "Targeting: on" for user-level targeting to work.
await ldApi.setFeatureFlagForUser({
featureFlagKey: 'my-flag-key',
userId: 'string user id',
variationIndex: 1, // must be index to one of the variations
})
removeTarget
Removes the specified target object
await ldApi.removeTarget({
featureFlagKey: 'my-flag-key',
targetIndex: 0,
})
removeUserTarget
Removes the given user from any variation targeting lists for the given feature
await ldApi.removeUserTarget({
featureFlagKey: 'my-flag-key',
userId: 'user string id',
})
Use without Cypress
You can use this plugin by itself to control LaunchDarkly flags
// https://github.com/bahmutov/cypress-ld-control
const { initLaunchDarklyApiClient } = require('cypress-ld-control')
const ldApi = initLaunchDarklyApiClient({
projectKey: process.env.LAUNCH_DARKLY_PROJECT_KEY,
authToken: process.env.LAUNCH_DARKLY_AUTH_TOKEN,
environment: 'test', // the key of the environment to use
})
const flag = await ldApi.getFeatureFlag('my-flag-key')
await ldApi.setFeatureFlagForUser({
featureFlagKey: 'my-flag-key',
userId: '1234567',
variationIndex: 0, // index of the variant to use
})
See demo/index.js
Use from Cypress
Add the plugin to your Cypress plugins file by grabbing an object with tasks.
initCypress
From your Cypress config file (v10+) or from your plugins file, call the initCypress
function.
// cypress.config.js
const { initCypress } = require('cypress-ld-control')
setupNodeEvents(on, config) {
initCypress(on, config)
// IMPORTANT: return the updated config object
return config
}
Reads the environment variables LAUNCH_DARKLY_PROJECT_KEY
and LAUNCH_DARKLY_AUTH_TOKEN
to initialize the LD client. You can pass the LD environment name via LAUNCH_DARKLY_ENVIRONMENT
, otherwise it assumes the LD environment name is "test".
initCypressMultipleProjects
Sometimes you might have several LaunchDarkly projects. You can control each one, and all you need is LAUNCH_DARKLY_AUTH_TOKEN
environment variable.
// cypress.config.js
const { initCypressMultipleProjects } = require('cypress-ld-control')
setupNodeEvents(on, config) {
// list all the LD projects you want to use
const projects = [
{
projectKey: 'demo-project',
environment: 'test',
},
{
projectKey: 'api-project',
environment: 'test',
},
]
initCypressMultipleProjects(projects, on, config)
// IMPORTANT: return the updated config object
return config
}
When calling the cy
custom commands from commands.js pass the project key, for example
cy.getFeatureFlag(featureFlagKey, projectKey)
Project names
Since some projects might have "default" as the project key, you can give them your own "name"
// list all the LD projects you want to use
const projects = [
{
name: 'web-flags',
projectKey: 'default',
environment: 'test',
},
{
projectKey: 'api-project',
environment: 'test',
},
]
initCypressMultipleProjects(projects, on, config)
In the situation above you can get the flag for first project using either of the two keys:
cy.getFeatureFlag('my-flag', 'default')
cy.getFeatureFlag('my-flag', 'web-flags')
Explicit registration (old)
Tip: you might want to check if the environment variables and
are set and only initialize the tasks in that case.
// cypress/plugins/index.js
const { initLaunchDarklyApiTasks } = require('cypress-ld-control')
module.exports = (on, config) => {
const tasks = {
// add your other Cypress tasks if any
}
// https://github.com/bahmutov/cypress-ld-control
if (
process.env.LAUNCH_DARKLY_PROJECT_KEY &&
process.env.LAUNCH_DARKLY_AUTH_TOKEN
) {
const ldApiTasks = initLaunchDarklyApiTasks({
projectKey: process.env.LAUNCH_DARKLY_PROJECT_KEY,
authToken: process.env.LAUNCH_DARKLY_AUTH_TOKEN,
environment: 'test', // the key of the environment to use
})
// copy all LaunchDarkly methods as individual tasks
Object.assign(tasks, ldApiTasks)
} else {
console.log('Skipping cypress-ld-control plugin')
}
// register all tasks with Cypress
on('task', tasks)
// IMPORTANT: return the updated config object
return config
}
Each method from the API (see above) has a matching task prefixed with cypress-ld-control:
string. For example, to see a particular flag from your spec call:
// in your Cypress spec file
// let's find everything about a feature flag
cy.task('cypress-ld-control:getFeatureFlag', 'my-flag-key').then(flag => {...})
// let's set the feature variation for a user
cy.task('cypress-ld-control:setFeatureFlagForUser', {
featureFlagKey: 'my-flag-key',
userId: 'string user id',
variationIndex: 1 // must be index to one of the variations
})
Examples
- application bahmutov/cypress-ld-control-example
Types
In src/index.d.ts file and src/globals.d.ts
Small print
Author: Gleb Bahmutov <[email protected]> © 2022
License: MIT - do anything with the code, but don't blame me if it does not work.
Support: if you find any problems with this module, email / tweet / open issue on Github
MIT License
Copyright (c) 2022 Gleb Bahmutov <[email protected]>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.