Add unit tests for UInt64LinkedList contract

cadence/tests/uint64_linked_list_test.cdc

@@ -0,0 +1,163 @@
+import Test
+import "UInt64LinkedList"
+
+access(all) fun setup() {
+    let err = Test.deployContract(
+        name: "UInt64LinkedList",
+        path: "../contracts/UInt64LinkedList.cdc",
+        arguments: []
+    )
+    Test.expect(err, Test.beNil())
+}
+
+// ─── Tests ───────────────────────────────────────────────────────────────────
+
+access(all) fun test_EmptyListState() {
+    let list <- UInt64LinkedList.createList()
+    let ok = list.head == nil
+        && list.tail == nil
+        && !list.contains(id: 1)
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_InsertSingle() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 42)
+    let ok = list.contains(id: 42)
+        && list.head == 42
+        && list.tail == 42
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_InsertMultiple_HeadAndTailOrder() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 1)
+    list.insertAtHead(id: 2)
+    list.insertAtHead(id: 3)
+    // head = 3 (most recent), tail = 1 (oldest)
+    let ok = list.head == 3 && list.tail == 1
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_Contains() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 10)
+    list.insertAtHead(id: 20)
+    let ok = list.contains(id: 10)
+        && list.contains(id: 20)
+        && !list.contains(id: 99)
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_RemoveSingle() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 7)
+    let removed = list.remove(id: 7)
+    let ok = removed
+        && list.head == nil
+        && list.tail == nil
+        && !list.contains(id: 7)
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_RemoveHead() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 1)
+    list.insertAtHead(id: 2)
+    list.insertAtHead(id: 3)
+    // list: 3 <-> 2 <-> 1  (head=3, tail=1)
+    let removed = list.remove(id: 3)
+    // list: 2 <-> 1
+    let ok = removed && list.head == 2 && list.tail == 1
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_RemoveTail() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 1)
+    list.insertAtHead(id: 2)
+    list.insertAtHead(id: 3)
+    // list: 3 <-> 2 <-> 1  (head=3, tail=1)
+    let removed = list.remove(id: 1)
+    // list: 3 <-> 2
+    let ok = removed && list.head == 3 && list.tail == 2
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_RemoveMiddle() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 1)
+    list.insertAtHead(id: 2)
+    list.insertAtHead(id: 3)
+    // list: 3 <-> 2 <-> 1
+    let removed = list.remove(id: 2)
+    // list: 3 <-> 1
+    let ok = removed
+        && list.head == 3
+        && list.tail == 1
+        && !list.contains(id: 2)
+        && list.contains(id: 3)
+        && list.contains(id: 1)
+    destroy list
+    Test.assertEqual(true, ok)
+}
+
+access(all) fun test_RemoveAbsent() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 5)
+    let removed = list.remove(id: 999)
+    destroy list
+    Test.assertEqual(true, !removed)
+}
+
+access(all) fun test_RemoveFromEmpty() {
+    let list <- UInt64LinkedList.createList()
+    let removed = list.remove(id: 42)
+    destroy list
+    Test.assertEqual(true, !removed)
+}
+
+access(all) fun test_TailWalk_Order() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 1)
+    list.insertAtHead(id: 2)
+    list.insertAtHead(id: 3)
+    // head=3, tail=1 → tailWalk yields [1, 2, 3]
+    let walked = list.tailWalk(limit: 10)
+    destroy list
+    let expected: [UInt64] = [1, 2, 3]
+    Test.assertEqual(expected, walked)
+}
+
+access(all) fun test_TailWalk_Limit() {
+    let list <- UInt64LinkedList.createList()
+    list.insertAtHead(id: 1)
+    list.insertAtHead(id: 2)
+    list.insertAtHead(id: 3)
+    let walked = list.tailWalk(limit: 2)
+    destroy list
+    Test.assertEqual(2, walked.length)
+}
+
+access(all) fun test_TailWalk_Empty() {
+    let list <- UInt64LinkedList.createList()
+    let walked = list.tailWalk(limit: 5)
+    destroy list
+    Test.assertEqual(0, walked.length)
+}
+
+access(all) fun test_InsertDuplicate_Panics() {
+    Test.expectFailure(fun() {
+        let list <- UInt64LinkedList.createList()
+        list.insertAtHead(id: 1)
+        list.insertAtHead(id: 1)
+        destroy list
+    }, errorMessageSubstring: "ID already exists in list")
+}