Adding pagination tests

AuroraSignal.test/CursorList.test.cs

@@ -1,8 +1,11 @@
 using Xunit;
-using Aurora;
 using Aurora.Services.Signal;
 using Aurora.Cursor;
 using Faker;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
 
 
 namespace AuroraSignal.test
@@ -81,5 +84,84 @@ namespace AuroraSignal.test
                 Assert.Equal(res.Result.Count, size);
             }
         }
+
+        [Theory()]
+        [InlineData(2)]
+        [InlineData(10)]
+        [InlineData(3)]
+        public void CursorPaginationTest(int pageSize)
+        {
+            int numOfItems = 50;
+            CursorList<Party> list = new CursorList<Party>();
+
+            // Add items to cursor list
+            for (int i = 0; i < numOfItems; i++)
+            {
+                list.Add(new Party()
+                {
+                    Name = string.Join(" ",
+                    Faker.Lorem.Words(2)),
+                    Id = Faker.RandomNumber.Next().ToString()
+                });
+            }
+
+            string pageToken = null;
+            Cursor<Party> cursor = new Cursor<Party>(ref list);
+            List<Party> pagedResults = new List<Party>();
+            while (pageToken != string.Empty)
+            {
+                CursorResult<Party> res = cursor
+                    .WithSize(pageSize)
+                    .WithNextPageToken(pageToken)
+                    .GetNextPage();
+
+                pagedResults.AddRange(res.Result);
+                pageToken = res.NextPageToken;
+            }
+
+            Assert.Equal(pagedResults.Count, numOfItems);
+        }
+
+        [Fact()]
+
+        public void CursorPaginationWithSortTest()
+        {
+            int numOfItems = 50;
+            CursorList<Party> cursorList = new CursorList<Party>();
+
+            // Add items to cursor list
+            for (int i = 0; i < numOfItems; i++)
+            {
+                cursorList.Add(new Party()
+                {
+                    Name = string.Join(" ",
+                    Faker.Lorem.Words(2)),
+                    Id = Faker.RandomNumber.Next().ToString()
+                });
+            }
+
+            var orderedList = cursorList.ToList().OrderBy(item => item.Value.Name).ToList().ConvertAll(item => item.Value);
+
+            string pageToken = null;
+            Cursor<Party> cursor = new Cursor<Party>(ref cursorList);
+            List<Party> pagedResults = new List<Party>();
+            while (pageToken != string.Empty)
+            {
+                CursorResult<Party> res = cursor
+                    .WithSize(10)
+                    .WithSort(item => item.Value.Name, SortDirection.Asc)
+                    .WithNextPageToken(pageToken)
+                    .GetNextPage();
+
+                pagedResults.AddRange(res.Result);
+                pageToken = res.NextPageToken;
+            }
+
+            var list = cursorList.ToList();
+            for (int i = 0; i < orderedList.Count; i++)
+            {
+                Assert.Equal(orderedList[i], pagedResults[i]);
+            }
+        }
     }
 }

AuroraSignal/Src/Cursor/Cursor.cs

@@ -28,7 +28,7 @@ namespace Aurora.Cursor
             this._pageSize = 10;
             this._sortDelgate = delegate (KeyValuePair<string, T> item)
             {
-                return item.Value.Id;
+                return item.Key;
             };
         }
 
@@ -60,17 +60,26 @@ namespace Aurora.Cursor
             if (!string.IsNullOrEmpty(this._nextPageToken))
             {
                 // TODO find another way to index into the list that's not a regular array search
-                startIdx = tmpList.FindIndex(item => item.Key == this._nextPageToken);
+                startIdx = tmpList.FindIndex(item => item.Key == this._nextPageToken) + 1;
             }
 
-            int endIdx = startIdx + this._pageSize;
+            int adjustedSize = this._pageSize;
+            if (startIdx + this._pageSize > tmpList.Count)
+            {
+                adjustedSize = this._pageSize - ((startIdx + _pageSize) - tmpList.Count);
+            }
 
-            List<KeyValuePair<string, T>> selection = tmpList.GetRange(startIdx, this._pageSize > tmpList.Count ? tmpList.Count : this._pageSize);
+
+            List<KeyValuePair<string, T>> selection = new List<KeyValuePair<string, T>>();
+            if (adjustedSize != 0)
+            {
+                selection = tmpList.GetRange(startIdx, adjustedSize);
+            }
 
             return new CursorResult<T>
             {
-                NextPageToken = selection[selection.Count - 1].Key,
+                NextPageToken = this._pageSize == selection.Count ? selection[selection.Count - 1].Key : string.Empty,
-                PrevPageToken = selection[0].Key,
+                PrevPageToken = string.Empty,
                 Count = this._list.Count,
                 Result = selection.ConvertAll(item => item.Value)
             };