Testing data or rules 2

pruchase.ts

// this is hard-coded data
// probably it comes from the business rules
const MIN_POINTS = 5

// the argument is a dynamic data
// it might come from another place on the codebase
// or somewhere else, like a database
function calculateFidelity({ type, experiments }: User, products: [Product]) {
    const points = products.reduce(
        (total,{ fidelityPoints }) => total + fidelityPoints,
        MIN_POINTS
    )
    
    if (experiments.includes(INCREASE_FIDELITY_GAMA)) {
        points *= 3
    }
    

    //in js/ts we don't know if `type.fidelity` is a data or a rule (getter)
    return type.fidelityModifier * points
}