From 72cc0606f490c2aa45dda6db0bb0f72cedde7ebf Mon Sep 17 00:00:00 2001
From: Logan Dam <dam.loganza@gmail.com>
Date: Thu, 8 Nov 2018 21:15:46 +0200
Subject: [PATCH 1/4] Call base.Close() in MockFileStream.Close()

---
 System.IO.Abstractions.TestingHelpers/MockFileStream.cs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/System.IO.Abstractions.TestingHelpers/MockFileStream.cs b/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
index 68095d85a..f984dd5f5 100644
--- a/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
+++ b/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
@@ -66,6 +66,7 @@ public override void Close()
         {
             InternalFlush();
             OnClose();
+            base.Close();
         }
 #else
         protected override void Dispose(bool disposing)

From 16dcfdcad5d2ba1531978698ec4a7a4f30d157f5 Mon Sep 17 00:00:00 2001
From: Logan Dam <dam.loganza@gmail.com>
Date: Thu, 8 Nov 2018 21:32:29 +0200
Subject: [PATCH 2/4] Check if we are closed already before trying to close
 again (fixes multiple calls to Close() throwing)

---
 System.IO.Abstractions.TestingHelpers/MockFileStream.cs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/System.IO.Abstractions.TestingHelpers/MockFileStream.cs b/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
index f984dd5f5..e405880f8 100644
--- a/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
+++ b/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
@@ -8,6 +8,7 @@ public class MockFileStream : MemoryStream
         private readonly bool canWrite = true;
         private readonly FileOptions options;
         private bool disposed;
+        private bool closed;
 
         public enum StreamType
         {
@@ -64,9 +65,14 @@ public MockFileStream(
 #if NET40
         public override void Close()
         {
+            if(closed)
+            {
+                return;
+            }
             InternalFlush();
             OnClose();
             base.Close();
+            closed = true;
         }
 #else
         protected override void Dispose(bool disposing)

From 5477fe7f81cdf2d9b55e49dfd6085997cab4d6af Mon Sep 17 00:00:00 2001
From: Logan Dam <dam.loganza@gmail.com>
Date: Fri, 9 Nov 2018 11:18:34 +0200
Subject: [PATCH 3/4] - Call base.Close() before OnClose() to keep consistent
 with Dispose() - Whitespace fix

---
 System.IO.Abstractions.TestingHelpers/MockFileStream.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/System.IO.Abstractions.TestingHelpers/MockFileStream.cs b/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
index e405880f8..b9dc51e6a 100644
--- a/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
+++ b/System.IO.Abstractions.TestingHelpers/MockFileStream.cs
@@ -65,13 +65,13 @@ public MockFileStream(
 #if NET40
         public override void Close()
         {
-            if(closed)
+            if (closed)
             {
                 return;
             }
             InternalFlush();
-            OnClose();
             base.Close();
+            OnClose();
             closed = true;
         }
 #else

From c7f96cc7b41e7ac1d1d7be845ab640871dfaa760 Mon Sep 17 00:00:00 2001
From: Logan Dam <dam.loganza@gmail.com>
Date: Fri, 9 Nov 2018 11:19:23 +0200
Subject: [PATCH 4/4] Added test case for #397

---
 .../MockFileStreamTests.cs                        | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs b/System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs
index ec3781b4c..89fe72551 100644
--- a/System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs
+++ b/System.IO.Abstractions.TestingHelpers.Tests/MockFileStreamTests.cs
@@ -106,5 +106,20 @@ public void MockFileStream_Dispose_MultipleCallsDontThrow()
             // Assert
             Assert.DoesNotThrow(() => stream.Dispose());
         }
+
+        [Test]
+        public void MockFileStream_Dispose_OperationsAfterDisposeThrow()
+        {
+            var fileSystem = new MockFileSystem();
+            var path = XFS.Path("C:\\test");
+            fileSystem.AddFile(path, new MockFileData(new byte[0]));
+            var stream = fileSystem.FileInfo.FromFileName(path).OpenWrite();
+
+            // Act
+            stream.Dispose();
+
+            // Assert
+            Assert.Throws<ObjectDisposedException>(() => stream.WriteByte(0));
+        }
     }
 }