feature-toggles.md

Maintaining the repo

One of the practices followed while maintaining this repository is the use of feature toggles, and there are some utilities in this project to make it easy to follow the practice:

1. A central place to keep the values of the toggles
2. Mechanism to read the value of the toggles by their name
3. Mechanism to override the toggles values in the application if needed

Example

Adding a new toggle, myToggle, disabled by default, with a value of false, for this we would create a new property, in the src/config/featureToggles.js file:

export const featureToggles = {
    myToggle: false
}

Then we can check its actual value in any React component, using a custom react hook that is available

import {useFeatureToggle} from '..path-to-config-folder../config/togglesSlice' 

const AnyComponent = () => {
    const myToggleValue = useFeatureToggle('myToggle') // false
    // rest of the component
}

We could override the value of the toggle in runtime with query string parameters in the URL, in different environments, as follows:

• In local environment: http://localhost:3000?myToggle=true
• In production environment https://codebar.github.io/pairing-tool/?myToggle=true

Valid values are true or false. Invalid values will fall back to false.

Once the feature is complete, we can release it by swapping the value in src/config/featureToggles.js to true, and after the deployment of this change the feature will be available for everyone.

Finally, after the release, once confirmed the feature is stable and there will be no need to turn the feature off, then the toggle can be removed, by first deleting their usages in production code and tests, and lastly from the toggles file