Tagging features

Tagging your features lets targets select smaller groups of features for generated datafiles.

Configuration#

Every Featurevisor project needs to define a set of tags in the configuration file:

featurevisor.config.js

module.exports = {
  tags: [
    'web',
    'mobile',
    // add more tags here...
  ],
  environments: [
    'staging',
    'production',
  ],
}

Defining features#

Above configuration enables you to define your features against one or more tags as follows:

features/my_feature.yml

description: My feature
tags:
  - web
# ...

Learn more about defining features.

Building datafiles#

Tags do not create datafiles on their own. Define targets that select the tags you need:

targets/web.yml

description: Web app
tag: web

When building datafiles, Featurevisor creates datafiles for targets.

Consuming datafile#

Now from your application, you can choose which datafile to load:

your-app/index.js

import { createFeaturevisor } from '@featurevisor/sdk'
const datafileUrl = 'https://cdn.yoursite.com/production/featurevisor-web.json'
const datafileContent = await fetch(datafileUrl).then((res) => res.json())
const f = createFeaturevisor({
  datafile: datafileContent,
})

Learn more about SDKs.

Testing features against targets#

When writing a feature's test spec, use the target property:

tests/features/my_feature.spec.yml

feature: my_feature
assertions:
  - environment: production
    at: 90
    context:
      country: nl
    target: web
    expectedToBeEnabled: true

The test runner builds target datafiles in memory automatically:

$ npx featurevisor test