product-types.ts

// TypeScript-specific way to ensure that other objects with the same shape
// can’t be interpreted as this type
declare const NsType: unique symbol
declare const LbfsType: unique symbol

// Ns effectively just wraps a value of type number.
class Ns {
  readonly value: number;
  [NsType]: void

  constructor(value: number) {
    this.value = value
  }
}

// Similarly, Lbfs type wraps a number and a unique symbol.
class Lbfs {
  readonly value: number;
  [LbfsType]: void

  constructor(value: number) {
    this.value = value
  }
}

function lbfsToNs(lbfs: Lbfs): Ns {
  return new Ns(lbfs.value * 4.448222)
}

function trajectoryCorrection(momentum: Ns) {
  if (momentum.value < new Ns(2).value) {
    // disintegrate()
  }
}

function provideMomentum() {
  trajectoryCorrection(lbfsToNs(new Lbfs(1.5)))
}