diff --git a/TypeScript/test/jest/gilded-rose.spec.ts b/TypeScript/test/jest/gilded-rose.spec.ts
index 6533075095..2a668568ca 100644
--- a/TypeScript/test/jest/gilded-rose.spec.ts
+++ b/TypeScript/test/jest/gilded-rose.spec.ts
@@ -1,9 +1,115 @@
-import { Item, GildedRose } from '@/gilded-rose';
+import { Item, GildedRose } from "@/gilded-rose";
 
-describe('Gilded Rose', () => {
-  it('should foo', () => {
-    const gildedRose = new GildedRose([new Item('foo', 0, 0)]);
-    const items = gildedRose.updateQuality();
-    expect(items[0].name).toBe('fixme');
+describe("Gilded Rose", () => {
+  describe("Normal items", () => {
+    it("should decrease quality by 1", () => {
+      const gildedRose = new GildedRose([new Item("foo", 1, 1)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(0);
+    });
+
+    it("should decrease sellIn by 1", () => {
+      const gildedRose = new GildedRose([new Item("foo", 1, 1)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].sellIn).toBe(0);
+    });
+
+    it("should decrease quality by 2 after sellIn", () => {
+      const gildedRose = new GildedRose([new Item("foo", 0, 2)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(0);
+    });
+
+    it("should not decrease quality below 0", () => {
+      const gildedRose = new GildedRose([new Item("foo", 1, 0)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(0);
+    });
+
+    it("should not decrease quality below 0 after sellIn", () => {
+      const gildedRose = new GildedRose([new Item("foo", 0, 0)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(0);
+    });
+  });
+
+  describe("Aged Brie", () => {
+    it("should increase quality by 1", () => {
+      const gildedRose = new GildedRose([new Item("Aged Brie", 1, 1)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(2);
+    });
+
+    it("should increase quality by 2 after sellIn", () => {
+      const gildedRose = new GildedRose([new Item("Aged Brie", 0, 1)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(3);
+    });
+  });
+
+  describe("Sulfuras", () => {
+    it("should not change quality", () => {
+      const gildedRose = new GildedRose([
+        new Item("Sulfuras, Hand of Ragnaros", 1, 80),
+      ]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(80);
+    });
+
+    it("should not change sellIn", () => {
+      const gildedRose = new GildedRose([
+        new Item("Sulfuras, Hand of Ragnaros", 1, 80),
+      ]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].sellIn).toBe(1);
+    });
+  });
+
+  describe("Backstage passes", () => {
+    it("should increase quality by 1", () => {
+      const gildedRose = new GildedRose([
+        new Item("Backstage passes to a TAFKAL80ETC concert", 11, 1),
+      ]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(2);
+    });
+
+    it("should increase quality by 2 when 10 days or less", () => {
+      const gildedRose = new GildedRose([
+        new Item("Backstage passes to a TAFKAL80ETC concert", 10, 1),
+      ]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(3);
+    });
+
+    it("should increase quality by 3 when 5 days or less", () => {
+      const gildedRose = new GildedRose([
+        new Item("Backstage passes to a TAFKAL80ETC concert", 5, 1),
+      ]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(4);
+    });
+
+    it("should drop quality to 0 after sellIn", () => {
+      const gildedRose = new GildedRose([
+        new Item("Backstage passes to a TAFKAL80ETC concert", 0, 1),
+      ]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(0);
+    });
+  });
+
+  describe("Conjured items", () => {
+    it("should decrease quality by 2", () => {
+      const gildedRose = new GildedRose([new Item("Conjured", 1, 2)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(0);
+    });
+
+    it("should decrease quality by 4 after sellIn", () => {
+      const gildedRose = new GildedRose([new Item("Conjured", 0, 4)]);
+      const items = gildedRose.updateQuality();
+      expect(items[0].quality).toBe(0);
+    });
   });
 });