Adding TimeoutHelper in order to make sure that long running test eventually times out. (#1160)

src/System.Device.Gpio.Tests/GpioControllerTestBase.cs

@@ -387,25 +387,28 @@ namespace System.Device.Gpio.Tests
         [Fact]
         public void WaitForEventFallingEdgeTest()
         {
-            using (GpioController controller = new GpioController(GetTestNumberingScheme(), GetTestDriver()))
+            TimeoutHelper.CompletesInTime(() =>
             {
-                CancellationTokenSource tokenSource = new CancellationTokenSource();
-                controller.OpenPin(InputPin, PinMode.Input);
-                controller.OpenPin(OutputPin, PinMode.Output);
-                controller.Write(OutputPin, PinValue.Low);
-
-                Task.Run(() =>
+                using (GpioController controller = new GpioController(GetTestNumberingScheme(), GetTestDriver()))
                 {
-                    controller.Write(OutputPin, PinValue.High);
-                    Thread.Sleep(WaitMilliseconds);
+                    CancellationTokenSource tokenSource = new CancellationTokenSource();
+                    controller.OpenPin(InputPin, PinMode.Input);
+                    controller.OpenPin(OutputPin, PinMode.Output);
                     controller.Write(OutputPin, PinValue.Low);
-                });
 
-                WaitForEventResult result = controller.WaitForEvent(InputPin, PinEventTypes.Falling, tokenSource.Token);
+                    Task.Run(() =>
+                    {
+                        controller.Write(OutputPin, PinValue.High);
+                        Thread.Sleep(WaitMilliseconds);
+                        controller.Write(OutputPin, PinValue.Low);
+                    });
 
-                Assert.False(result.TimedOut);
-                Assert.Equal(PinEventTypes.Falling, result.EventTypes);
-            }
+                    WaitForEventResult result = controller.WaitForEvent(InputPin, PinEventTypes.Falling, tokenSource.Token);
+
+                    Assert.False(result.TimedOut);
+                    Assert.Equal(PinEventTypes.Falling, result.EventTypes);
+                }
+            }, TimeSpan.FromSeconds(30));
         }
 
         [Fact]

src/System.Device.Gpio.Tests/TimeoutHelper.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information
+
+using System.Threading.Tasks;
+
+namespace System.Device.Gpio.Tests
+{
+    public static class TimeoutHelper
+    {
+        public static void CompletesInTime(Action test, TimeSpan timeout)
+        {
+            Task task = Task.Run(test);
+            bool completedInTime = Task.WaitAll(new[] { task }, timeout);
+
+            if (task.Exception != null)
+            {
+                if (task.Exception.InnerExceptions.Count == 1)
+                {
+                    throw task.Exception.InnerExceptions[0];
+                }
+
+                throw task.Exception;
+            }
+
+            if (!completedInTime)
+            {
+                throw new TimeoutException($"Test did not complete in the specified timeout: {timeout.TotalSeconds} seconds.");
+            }
+        }
+    }
+}