Clear IsLoading when exception occurs.

Author: grokys

src/GitHub.App/Collections/SequentialListSource.cs

@@ -182,13 +182,18 @@ async Task Load()
         {
             OnBeginLoading();
 
-            while (nextPage <= loadTo && !disposed)
+            try
             {
-                await LoadNextPage().ConfigureAwait(false);
-                PageLoaded?.Invoke(this, EventArgs.Empty);
+                while (nextPage <= loadTo && !disposed)
+                {
+                    await LoadNextPage().ConfigureAwait(false);
+                    PageLoaded?.Invoke(this, EventArgs.Empty);
+                }
+            }
+            finally
+            {
+                OnEndLoading();
             }
-
-            OnEndLoading();
         }
 
         async Task LoadNextPage()

test/GitHub.App.UnitTests/Collections/SequentialListSourceTests.cs

@@ -46,6 +46,17 @@ public void GetPage_Should_Stop_Loading_Pages_When_LoadPage_Throws()
             Assert.That(target.PagesLoaded, Is.EqualTo(new[] { 0, 1 }));
         }
 
+        [Test]
+        public void IsLoading_Should_Be_Set_To_False_When_LoadPage_Throws()
+        {
+            var target = new TestSource(2);
+
+            Assert.That(target.PagesLoaded, Is.Empty);
+
+            Assert.ThrowsAsync<AggregateException>(() => target.GetPage(3));
+            Assert.That(target.IsLoading, Is.False);
+        }
+
         class TestSource : SequentialListSource<string, string>
         {
             const int PageCount = 10;