feat: the kata machine

src/__tests__/doubly-linked-list.ts

@@ -0,0 +1,21 @@
+import LinkedList from "@code/doubly-linked-list";
+
+test("linked-list", function() {
+    const list = new LinkedList<number>();
+
+    list.add(5);
+    list.add(7);
+    list.add(9);
+
+    expect(list.remove()).toEqual(5);
+    expect(list.length).toEqual(2);
+
+    list.add(11);
+    expect(list.remove()).toEqual(7);
+    expect(list.remove()).toEqual(9);
+    expect(list.remove()).toEqual(11);
+    expect(list.remove()).toEqual(undefined);
+});
+
+
+