@netlify/config/lib/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 = {};