Franc (CHF) multiplication

src/franc/index.spec.ts

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+import Franc from '.';
+
+describe('Franc', () => {
+  describe('multiplication', () => {
+    it('should multiply $5 by 2 and get $10', () => {
+      const five = new Franc(5);
+      const product = five.times(2);
+      expect(product.equals(new Franc(10))).toBe(true);
+    });
+
+    it('should preserve the initial dollar amount when multiplying multiple times', () => {
+      const five = new Franc(5);
+      let product: Franc = five.times(2);
+      expect(product.equals(new Franc(10))).toBe(true);
+      product = five.times(3);
+      expect(product.equals(new Franc(15))).toBe(true);
+    });
+  });
+});

src/franc/index.ts

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+export default class Franc {
+  private amount: number;
+
+  constructor(amount: number) {
+    this.amount = amount;
+  }
+
+  times(multiplier: number): Franc {
+    return new Franc(this.amount * multiplier);
+  }
+
+  equals(dollar: Object): boolean {
+    return this.amount == (dollar as Franc).amount;
+  }
+}