Testing data or rules 4

countryConfiguration.ts

//hard-coded data giving by business (probably) to "play safe"
const defaultConfiguration = {
    alcohol: 21,
    softDrugs: Infinity,
    hardDrugs: Infinity,
    drive: 21,
    adult: 21
}

// ts-magic, creates an interface-like type definition
// it uses a value as template, infering the types correctly
type Configuration = typeof defaultConfiguration

//hard-coded data giving by each country's law
//(not checked for accuracy)
//the Partial<T> allow us to not have to define values for all Configuration members
const dataset: Record<string, Partial<Configuration>> = {
  [Country.Brazil]: { alcohol: 18, drive: 18, adult: 18 },
  [Country.SaudiArabia]: { alcohol: Infinity, adult: Infinity },
  [Country.Netherlands]: { drive: 16, softDrugs: 18 },
  [Country.USA]: { drive: 16, adult: 18 }
}

// js-magic, merges the default and the argument-related record
// in a way that the client code always will have some values
// even when the record does not especify them
export const getCountryConfiguration = (
  country: Country
): Configuration => ({
    ...defaultConfiguration,
    ...dataset[country]
})