Tests some internals.

Increase overall coverage.

tests/NScatterGather.Tests/Internals/CancellationTokenTaskSourceTests.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace NScatterGather.Internals
+{
+    public class CancellationTokenTaskSourceTests
+    {
+        [Fact]
+        public void Task_is_immediately_canceled()
+        {
+            var token = new CancellationToken(true);
+            using var source = new CancellationTokenTaskSource<object>(token);
+            Assert.True(source.Task.IsCanceled);
+        }
+
+        [Fact(Timeout = 5000)]
+        public async Task Task_completes_after_expected_time()
+        {
+            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(2));
+            using var source = new CancellationTokenTaskSource<object>(cts.Token);
+
+            bool canceled = false;
+
+            try
+            {
+                await source.Task;
+            }
+            catch (TaskCanceledException)
+            {
+                canceled = true;
+            }
+
+            Assert.True(canceled);
+        }
+    }
+}