1 files changed, 58 insertions, 0 deletions
diff --git a/tst/collections_cons_zipper.test.ts b/tst/collections_cons_zipper.test.ts
new file mode 100644
index 0000000..3dfe75d
--- /dev/null
+++ b/tst/collections_cons_zipper.test.ts
@@ -0,0 +1,58 @@
+import { Cons, ListZipper } from '../lib/index';
+
+describe('types/collections/cons + zipper', () => {
+    test('Cons.from iterates in order', () => {
+        const list = Cons.from([1, 2, 3]);
+        expect(Array.from(list.get())).toEqual([1, 2, 3]);
+    });
+
+    test('Cons.replace replaces head value', () => {
+        const list = Cons.from([1, 2]).get();
+        expect(Array.from(list.replace(9))).toEqual([9, 2]);
+    });
+
+    test('Cons.before prepends a head chain', () => {
+        const tail = Cons.from([2, 3]);
+        const head = new Cons(1).before(tail);
+        expect(Array.from(head)).toEqual([1, 2, 3]);
+    });
+
+    test('Cons.addOnto appends onto tail optional', () => {
+        const tail = Cons.from([3]);
+        const list = Cons.addOnto([1, 2], tail).get();
+        expect(Array.from(list)).toEqual([1, 2, 3]);
+    });
+
+    test('ListZipper navigation and edits', () => {
+        const zipper = ListZipper.from([1, 2, 3]);
+
+        expect(zipper.read().get()).toBe(1);
+        const z2 = zipper.next().get() as ListZipper<number>;
+        expect(z2.read().get()).toBe(2);
+
+        const z3 = z2.replace(9) as ListZipper<number>;
+        expect(z3.collection()).toEqual([1, 9, 3]);
+
+        const z4 = z3.remove() as ListZipper<number>;
+        expect(z4.collection()).toEqual([1, 3]);
+
+        const z5 = z4.prependChunk([7, 8]) as ListZipper<number>;
+        expect(z5.collection()).toEqual([1, 7, 8, 3]);
+
+        const back = (z2.previous().get() as ListZipper<number>).read().get();
+        expect(back).toBe(1);
+    });
+
+    test('ListZipper iteration yields full list', () => {
+        const zipper = ListZipper.from([1, 2, 3]);
+        expect(Array.from(zipper)).toEqual([1, 2, 3]);
+
+        const moved = zipper.next().flatMap((z: any) => z.next());
+        expect(moved.present()).toBe(true);
+        expect(Array.from(moved.get())).toEqual([1, 2, 3]);
+
+        const empty = ListZipper.from<number>([]);
+        expect(empty.read().present()).toBe(false);
+        expect(Array.from(empty)).toEqual([]);
+    });
+});