Add Dollar class with the capability of being multiplied by scalars

src/index.spec.ts

@@ -0,0 +1,13 @@
+import Dollar from '.';
+
+describe('Multi currency money', () => {
+  it.todo('should sum $5 + 10CHF as being $10 if exchange rate is 2:1');
+
+  describe('multiplication', () => {
+    it('should multiply $5 by 2 and get $10', () => {
+      const five = new Dollar(5);
+      five.times(2);
+      expect(five.amount).toEqual(10);
+    });
+  });
+});

src/index.ts

@@ -1 +1,11 @@
-console.log('Hello world!');
+export default class Dollar {
+  amount: number;
+
+  constructor(amount: number) {
+    this.amount = amount;
+  }
+
+  times(multiplier: number) {
+    this.amount *= multiplier;
+  }
+}