Improve logging in FileShareOpen test

This test is still spuriously failing with sharing errors.  Adding some more logging to hopefully better understand why.

Author: stephentoub

src/System.IO.FileSystem/tests/FileStream/ctor_str_fm_fa_fs.cs

@@ -2,59 +2,55 @@
 // 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;
-using System.IO;
 using Xunit;
 
 namespace System.IO.Tests
 {
     public partial class FileStream_ctor_str_fm_fa_fs : FileStream_ctor_str_fm_fa
     {
-        protected override FileStream CreateFileStream(string path, FileMode mode, FileAccess access)
-        {
-            return CreateFileStream(path, mode, access, FileShare.Read);
-        }
+        protected override FileStream CreateFileStream(string path, FileMode mode, FileAccess access) =>
+            CreateFileStream(path, mode, access, FileShare.Read);
 
-        protected virtual FileStream CreateFileStream(string path, FileMode mode, FileAccess access, FileShare share)
-        {
-            return new FileStream(path, mode, access, share);
-        }
+        protected virtual FileStream CreateFileStream(string path, FileMode mode, FileAccess access, FileShare share) =>
+            new FileStream(path, mode, access, share);
 
         [Fact]
         public void InvalidShareThrows()
         {
             AssertExtensions.Throws<ArgumentOutOfRangeException>("share", () => CreateFileStream(GetTestFilePath(), FileMode.Create, FileAccess.ReadWrite, ~FileShare.None));
         }
 
-        static readonly FileShare[] shares = 
-            { 
-                FileShare.None,
-                FileShare.Inheritable,
-                FileShare.Delete, FileShare.Delete | FileShare.Inheritable, 
-                FileShare.Read, FileShare.Read | FileShare.Inheritable, FileShare.Read | FileShare.Delete, FileShare.Read | FileShare.Delete | FileShare.Inheritable,
-                FileShare.Write, FileShare.Write | FileShare.Inheritable, FileShare.Write | FileShare.Delete, FileShare.Write | FileShare.Delete | FileShare.Inheritable,
-                FileShare.ReadWrite, FileShare.ReadWrite | FileShare.Inheritable, FileShare.ReadWrite | FileShare.Delete, FileShare.ReadWrite | FileShare.Delete | FileShare.Inheritable
-            };
+        private static readonly FileShare[] s_shares =
+        {
+            FileShare.None,
+            FileShare.Inheritable,
+            FileShare.Delete, FileShare.Delete | FileShare.Inheritable,
+            FileShare.Read, FileShare.Read | FileShare.Inheritable, FileShare.Read | FileShare.Delete, FileShare.Read | FileShare.Delete | FileShare.Inheritable,
+            FileShare.Write, FileShare.Write | FileShare.Inheritable, FileShare.Write | FileShare.Delete, FileShare.Write | FileShare.Delete | FileShare.Inheritable,
+            FileShare.ReadWrite, FileShare.ReadWrite | FileShare.Inheritable, FileShare.ReadWrite | FileShare.Delete, FileShare.ReadWrite | FileShare.Delete | FileShare.Inheritable
+        };
 
         [Fact]
         public void FileShareOpen()
         {
             // create the file
             string fileName = GetTestFilePath();
-            using (FileStream fs = CreateFileStream(fileName, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite | FileShare.Delete))
-            { }
+            CreateFileStream(fileName, FileMode.CreateNew, FileAccess.ReadWrite, FileShare.ReadWrite | FileShare.Delete).Dispose();
 
             // just check that the inputs are accepted, actual sharing varies by platform so we separate the behavior testing
-            foreach(FileShare share in shares)
+            foreach (FileAccess access in new[] { FileAccess.ReadWrite, FileAccess.Write, FileAccess.Read })
             {
-                using (FileStream fs = CreateFileStream(fileName, FileMode.Open, FileAccess.ReadWrite, share))
-                { }
-
-                using (FileStream fs = CreateFileStream(fileName, FileMode.Open, FileAccess.Write, share))
-                { }
-
-                using (FileStream fs = CreateFileStream(fileName, FileMode.Open, FileAccess.Read, share))
-                { }
+                foreach (FileShare share in s_shares)
+                {
+                    try
+                    {
+                        CreateFileStream(fileName, FileMode.Open, access, share).Dispose();
+                    }
+                    catch (Exception e)
+                    {
+                        throw new Exception($"Failed with FileAccess {access} and FileShare {share}", e);
+                    }
+                }
             }
         }
 
@@ -63,13 +59,19 @@ public void FileShareCreate()
         {
             // just check that the inputs are accepted, actual sharing varies by platform so we separate the behavior testing
             int i = 0;
-            foreach (FileShare share in shares)
+            foreach (FileAccess access in new[] { FileAccess.ReadWrite, FileAccess.Write })
             {
-                using (FileStream fs = CreateFileStream(GetTestFilePath(i++), FileMode.Create, FileAccess.ReadWrite, share))
-                { }
-
-                using (FileStream fs = CreateFileStream(GetTestFilePath(i++), FileMode.Create, FileAccess.Write, share))
-                { }
+                foreach (FileShare share in s_shares)
+                {
+                    try
+                    {
+                        CreateFileStream(GetTestFilePath(i++), FileMode.Create, access, share).Dispose();
+                    }
+                    catch (Exception e)
+                    {
+                        throw new Exception($"Failed with FileAccess {access} and FileShare {share}", e);
+                    }
+                }
             }
         }
 
@@ -78,16 +80,19 @@ public void FileShareOpenOrCreate()
         {
             // just check that the inputs are accepted, actual sharing varies by platform so we separate the behavior testing
             int i = 0;
-            foreach (FileShare share in shares)
+            foreach (FileAccess access in new[] { FileAccess.ReadWrite, FileAccess.Write, FileAccess.Read })
             {
-                using (FileStream fs = CreateFileStream(GetTestFilePath(i++), FileMode.OpenOrCreate, FileAccess.ReadWrite, share))
-                { }
-
-                using (FileStream fs = CreateFileStream(GetTestFilePath(i++), FileMode.OpenOrCreate, FileAccess.Write, share))
-                { }
-
-                using (FileStream fs = CreateFileStream(GetTestFilePath(i++), FileMode.OpenOrCreate, FileAccess.Read, share))
-                { }
+                foreach (FileShare share in s_shares)
+                {
+                    try
+                    {
+                        CreateFileStream(GetTestFilePath(i++), FileMode.OpenOrCreate, access, share).Dispose();
+                    }
+                    catch (Exception e)
+                    {
+                        throw new Exception($"Failed with FileAccess {access} and FileShare {share}", e);
+                    }
+                }
             }
         }
     }