TS Workshop

moc-ts-workshop.md

type Tuple<Entity = number> = [Entity, Entity];
type Circle = number;
type Rectangle = Tuple;
type Triangle = [number, number, number];
type Shape = Circle | Rectangle | Triangle;

type ShapeEntity = {
    area: number;
    shape: Shape
}

type ShapeManager = { [k: number]: Function };

const SHAPES = [[4.23, 6.43], 1.23, 3.444, [1.342, 3.212]] satisfies Shape[];

const shapeManager = (): ShapeManager => {
  const circle = (r: Circle) => (Math.PI * r) ** 2;

  const rectangle = ([a, b]: Rectangle) => a * b;

  const triangle = ([a, b, c]: Triangle) => {
    const s = (a + b + c) / 2; // semiPerimeter
    return Math.sqrt(s * (s - a) * (s - b) * (s - c));
  };

  return {
    0: circle,
    2: rectangle,
    3: triangle,
  };
};

const sort = (tuple: Tuple<ShapeEntity>) =>
  tuple.sort((a, b) => a.area - b.area).map((i) => i.shape);

const getAreas = (shapes: Shape[]) => {
  const manager = shapeManager();
  const res = shapes.map((shape: Shape) => {
    const lines = typeof shape === 'number' ? 0 : shape?.length;
    return manager[lines](shape) ?? null;
  });

  const tuple = res.map((area: number, index: number): ShapeEntity => ({
    area,
    shape: shapes[index],
  })) as Tuple<ShapeEntity>;

  return sort(tuple);
};

const sortedArray = getAreas(SHAPES);

console.log(sortedArray);
console.log(sortedArray !== SHAPES);