Made batch extension much less fragile.

Simplified unit tests accordingly.

Author: fmelink

LinkMobility.PSWin.Client.Tests/EnumerableBatchExtensionTests.cs

@@ -29,13 +29,9 @@ public void Test_no_multiple_enumeration()
         {
             var checker = new MultipleEnumerationChecker();
             var items = checker.GetItems(30);
-            
-            var iteratedItems = 0;
-            foreach (var batch in items.Batch(10))
-                foreach (var item in batch)
-                    iteratedItems++;
 
-            Assume.That(iteratedItems, Is.GreaterThan(0));
+            items.Batch(10).Count();
+
             Assert.That(checker.Enumerations, Is.EqualTo(1), "Enumerations");
         }
 
@@ -54,11 +50,9 @@ public void Test_zero_batches()
         public void Test_one_batch(int itemCount)
         {
             var items = Enumerable.Range(0, itemCount).ToArray();
-            var batches = items.Batch(10);
-            var enumerator = batches.GetEnumerator();
-            Assert.That(enumerator.MoveNext(), Is.True, "At least one batch");
-            Assert.That(enumerator.Current, Is.EqualTo(Enumerable.Range(0, itemCount)), "Batch content");
-            Assert.That(enumerator.MoveNext(), Is.False, "No second batch");
+            var batches = items.Batch(10).ToArray();
+            Assert.That(batches.Length, Is.EqualTo(1), "Number of batches");
+            Assert.That(batches[0], Is.EqualTo(Enumerable.Range(0, itemCount)), "Batch content");
         }
 
         [Test]
@@ -68,13 +62,10 @@ public void Test_one_batch(int itemCount)
         public void Test_two_batches(int itemCount)
         {
             var items = Enumerable.Range(0, itemCount).ToArray();
-            var batches = items.Batch(10);
-            var enumerator = batches.GetEnumerator();
-            Assert.That(enumerator.MoveNext(), Is.True, "At least one batch");
-            Assert.That(enumerator.Current, Is.EqualTo(Enumerable.Range(0, 10)), "First batch content");
-            Assert.That(enumerator.MoveNext(), Is.True, "At least two batches");
-            Assert.That(enumerator.Current, Is.EqualTo(Enumerable.Range(10, itemCount - 10)), "Second batch content");
-            Assert.That(enumerator.MoveNext(), Is.False, "No third batch");
+            var batches = items.Batch(10).ToArray();
+            Assert.That(batches.Length, Is.EqualTo(2), "Number of batches");
+            Assert.That(batches[0], Is.EqualTo(Enumerable.Range(0, 10)), "First batch content");
+            Assert.That(batches[1], Is.EqualTo(Enumerable.Range(10, itemCount - 10)), "Second batch content");
         }
 
         public class MultipleEnumerationChecker

PSWin.Client/Extensions/EnumerableBatchExtension.cs

@@ -1,11 +1,12 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 
 namespace LinkMobility.PSWin.Client.Extensions
 {
     internal static class EnumerableBatchExtension
     {
-        public static IEnumerable<IEnumerable<T>> Batch<T>(this IEnumerable<T> self, uint batchSize)
+        public static IEnumerable<T[]> Batch<T>(this IEnumerable<T> self, uint batchSize)
         {
             if (batchSize <= 0)
                 throw new ArgumentOutOfRangeException(nameof(batchSize), batchSize, "Batch size must be greater than zero.");
@@ -25,7 +26,7 @@ IEnumerable<T> GetBatch()
 
             while (enumerator.MoveNext())
             {
-                yield return GetBatch();
+                yield return GetBatch().ToArray();
             }
         }
     }

PSWin.Client/Transports/XmlTransport.cs

@@ -52,9 +52,7 @@ public XmlTransport(string username, string password) : this(username, password,
         /// <inheritdoc/>
         public async Task<IEnumerable<MessageResult>> SendAsync(IEnumerable<Sms> messages, string sessionData = null)
         {
-            var messageBatches = messages
-                .Batch(BatchSize)
-                .Select(b => b.ToArray());
+            var messageBatches = messages.Batch(BatchSize);
             var results = new List<MessageResult>();
             foreach (var messageBatch in messageBatches)
             {