@netlify/config/src/options/feature_flags.js

Netlify config module

// From CLI `--featureFlags=a,b,c` to programmatic `{ a: true, b: true, c: true }`
export const normalizeCliFeatureFlags = function (cliFeatureFlags) {
  return Object.assign({}, ...cliFeatureFlags.split(',').filter(isNotEmpty).map(getFeatureFlag))
}

const isNotEmpty = function (name) {
  return name.trim() !== ''
}

const getFeatureFlag = function (name) {
  return { [name]: true }
}

// Default values for feature flags
export const DEFAULT_FEATURE_FLAGS = {}