io test helper

src/modules/fancyzones/UITests-FancyZonesEditor/UITests-FancyZonesEditor.csproj

@@ -22,9 +22,14 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="MSTest.TestAdapter" />
     <PackageReference Include="MSTest.TestFramework" />
+    <PackageReference Include="System.IO.Abstractions" />
   </ItemGroup>
 
   <ItemGroup>
     <Folder Include="Properties\" />
   </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\FancyZonesEditorCommon\FancyZonesEditorCommon.csproj" />
+  </ItemGroup>
 </Project>

src/modules/fancyzones/UITests-FancyZonesEditor/Utils/IOTestHelper.cs

@@ -0,0 +1,78 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation 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 System.IO.Abstractions;
+using System.Threading.Tasks;
+
+namespace Microsoft.FancyZonesEditor.UITests.Utils
+{
+    public class IOTestHelper
+    {
+        private readonly IFileSystem _fileSystem = new FileSystem();
+
+        private string _fileName;
+
+        private string _data = string.Empty;
+
+        public IOTestHelper(string fileName)
+        {
+            _fileName = fileName;
+
+            if (_fileSystem.File.Exists(_fileName))
+            {
+                _data = ReadFile(_fileName);
+            }
+        }
+
+        ~IOTestHelper()
+        {
+            RestoreData();
+        }
+
+        public void RestoreData()
+        {
+            if (_data != string.Empty)
+            {
+                WriteData(_data);
+            }
+            else
+            {
+                _fileSystem.File.Delete(_fileName);
+            }
+        }
+
+        public void WriteData(string data)
+        {
+            _fileSystem.File.WriteAllText(_fileName, data);
+        }
+
+        private string ReadFile(string fileName)
+        {
+            var attempts = 0;
+            while (attempts < 10)
+            {
+                try
+                {
+                    using (Stream inputStream = _fileSystem.File.Open(fileName, FileMode.Open))
+                    using (StreamReader reader = new StreamReader(inputStream))
+                    {
+                        string data = reader.ReadToEnd();
+                        inputStream.Close();
+                        return data;
+                    }
+                }
+                catch (Exception)
+                {
+                    Task.Delay(10).Wait();
+                }
+
+                attempts++;
+            }
+
+            return string.Empty;
+        }
+    }
+}