Added IFileSystemWatcher, IFile and IDirectory interfaces

README.md

@@ -13,7 +13,7 @@ and/or:
 
     Install-Package System.IO.Abstractions.TestingHelpers
 
-At the core of the library is IFileSystem and FileSystem. Instead of calling methods like `File.ReadAllText` directly, use `IFileSystem.File.ReadAllText`. We have exactly the same API, except that ours is injectable and testable.
+At the core of the library is `IFileSystem` and `FileSystem`. Instead of calling methods like `File.ReadAllText` directly, use `IFileSystem.File.ReadAllText`. We have exactly the same API, except that ours is injectable and testable.
 
 ```csharp
 public class MyComponent
@@ -28,7 +28,7 @@ public class MyComponent
     /// <summary>Create MyComponent</summary>
     public MyComponent() : this( 
         fileSystem: new FileSystem() //use default implementation which calls System.IO
-    ) 
+    )
     {
     }
 
@@ -74,17 +74,67 @@ public void MyComponent_Validate_ShouldThrowNotSupportedExceptionIfTestingIsNotA
     Assert.Fail("The expected exception was not thrown.");
 }
 ```
+
 We even support casting from the .NET Framework's untestable types to our testable wrappers:
 
 ```csharp
-FileInfo SomeBadApiMethodThatReturnsFileInfo()
+FileInfo SomeApiMethodThatReturnsFileInfo()
 {
     return new FileInfo("a");
 }
 
 void MyFancyMethod()
 {
-    var testableFileInfo = (FileInfoBase)SomeBadApiMethodThatReturnsFileInfo();
+    var testableFileInfo = (FileInfoBase)SomeApiMethodThatReturnsFileInfo();
     ...
 }
 ```
+
+Since version 4.0 the top-level APIs expose interfaces instead of abstract base classes (these still exist, though), allowing you to completely mock the file system. Here's a small example, using [Moq](https://github.com/moq/moq4):
+
+```csharp
+[Test]
+public void Test1()
+{
+    var watcher = Mock.Of<IFileSystemWatcher>();
+    var file = Mock.Of<IFile>();
+
+    Mock.Get(file).Setup(f => f.Exists(It.IsAny<string>())).Returns(true);
+    Mock.Get(file).Setup(f => f.ReadAllText(It.IsAny<string>())).Throws<OutOfMemoryException>();
+
+    var unitUnderTest = new SomeClassUsingFileSystemWatcher(watcher, file);
+
+    Assert.Throws<OutOfMemoryException>(() => {
+        Mock.Get(watcher).Raise(w => w.Created += null, new System.IO.FileSystemEventArgs(System.IO.WatcherChangeTypes.Created, @"C:\Some\Directory", "Some.File"));
+    });
+
+    Mock.Get(file).Verify(f => f.Exists(It.IsAny<string>()), Times.Once);
+
+    Assert.True(unitUnderTest.FileWasCreated);
+}
+
+public class SomeClassUsingFileSystemWatcher
+{
+    private readonly IFileSystemWatcher _watcher;
+    private readonly IFile _file;
+
+    public bool FileWasCreated { get; private set; }
+
+    public SomeClassUsingFileSystemWatcher(IFileSystemWatcher watcher, IFile file)
+    {
+        this._file = file;
+        this._watcher = watcher;
+        this._watcher.Created += Watcher_Created;
+    }
+
+    private void Watcher_Created(object sender, System.IO.FileSystemEventArgs e)
+    {
+        FileWasCreated = true;
+
+        if(_file.Exists(e.FullPath))
+        {
+            var text = _file.ReadAllText(e.FullPath);
+        }
+    }
+}
+```

System.IO.Abstractions.TestingHelpers.Tests/MockDirectoryArgumentPathTests.cs

@@ -6,7 +6,7 @@ namespace System.IO.Abstractions.TestingHelpers.Tests
 {
     public class MockDirectoryArgumentPathTests
     {
-        private static IEnumerable<Action<DirectoryBase>> GetFileSystemActionsForArgumentNullException()
+        private static IEnumerable<Action<IDirectory>> GetFileSystemActionsForArgumentNullException()
         {
             yield return ds => ds.Delete(null);
             yield return ds => ds.Delete(null, true);
@@ -26,7 +26,7 @@ private static IEnumerable<Action<DirectoryBase>> GetFileSystemActionsForArgumen
         }
 
         [TestCaseSource("GetFileSystemActionsForArgumentNullException")]
-        public void Operations_ShouldThrowArgumentNullExceptionIfPathIsNull(Action<DirectoryBase> action)
+        public void Operations_ShouldThrowArgumentNullExceptionIfPathIsNull(Action<IDirectory> action)
         {
             // Arrange
             var fileSystem = new MockFileSystem();

System.IO.Abstractions.TestingHelpers.Tests/MockFileArgumentPathTests.cs

@@ -7,7 +7,7 @@ namespace System.IO.Abstractions.TestingHelpers.Tests
 {
     public class MockFileArgumentPathTests
     {
-        private static IEnumerable<Action<FileBase>> GetFileSystemActionsForArgumentNullException()
+        private static IEnumerable<Action<IFile>> GetFileSystemActionsForArgumentNullException()
         {
             yield return fs => fs.AppendAllLines(null, new[] { "does not matter" });
             yield return fs => fs.AppendAllLines(null, new[] { "does not matter" }, Encoding.ASCII);
@@ -57,7 +57,7 @@ private static IEnumerable<Action<FileBase>> GetFileSystemActionsForArgumentNull
         }
 
         [TestCaseSource("GetFileSystemActionsForArgumentNullException")]
-        public void Operations_ShouldThrowArgumentNullExceptionIfPathIsNull(Action<FileBase> action)
+        public void Operations_ShouldThrowArgumentNullExceptionIfPathIsNull(Action<IFile> action)
         {
             // Arrange
             var fileSystem = new MockFileSystem();

System.IO.Abstractions.TestingHelpers.Tests/MockFileSystemTests.cs

@@ -352,8 +352,8 @@ public void MockFileSystem_FileSystemWatcher_ShouldBeAssignable()
 
         private class TestFileSystemWatcherFactory : IFileSystemWatcherFactory
         {
-            public FileSystemWatcherBase CreateNew() => new TestFileSystemWatcher(null);
-            public FileSystemWatcherBase FromPath(string path) => new TestFileSystemWatcher(path);
+            public IFileSystemWatcher CreateNew() => new TestFileSystemWatcher(null);
+            public IFileSystemWatcher FromPath(string path) => new TestFileSystemWatcher(path);
         }
 
         private class TestFileSystemWatcher : FileSystemWatcherBase

System.IO.Abstractions.TestingHelpers/IMockFileDataAccessor.cs

@@ -56,10 +56,10 @@ public interface IMockFileDataAccessor
 
         StringOperations StringOperations { get; }
 
-        FileBase File { get; }
-        DirectoryBase Directory { get; }
+        IFile File { get; }
+        IDirectory Directory { get; }
         IFileInfoFactory FileInfo {get; }
-        PathBase Path { get; }
+        IPath Path { get; }
         IDirectoryInfoFactory DirectoryInfo { get; }
         IDriveInfoFactory DriveInfo { get; }
 

System.IO.Abstractions.TestingHelpers/MockDirectory.cs

@@ -25,19 +25,19 @@ public MockDirectory(IMockFileDataAccessor mockFileDataAccessor, string currentD
             this.mockFileDataAccessor = mockFileDataAccessor ?? throw new ArgumentNullException(nameof(mockFileDataAccessor));
         }
 
-        public override DirectoryInfoBase CreateDirectory(string path)
+        public override IDirectoryInfo CreateDirectory(string path)
         {
             return CreateDirectoryInternal(path, null);
         }
 
 #if NET40
-        public override DirectoryInfoBase CreateDirectory(string path, DirectorySecurity directorySecurity)
+        public override IDirectoryInfo CreateDirectory(string path, DirectorySecurity directorySecurity)
         {
             return CreateDirectoryInternal(path, directorySecurity);
         }
 #endif
 
-        private DirectoryInfoBase CreateDirectoryInternal(string path, DirectorySecurity directorySecurity)
+        private IDirectoryInfo CreateDirectoryInternal(string path, DirectorySecurity directorySecurity)
         {
             if (path == null)
             {
@@ -312,7 +312,7 @@ public override string[] GetLogicalDrives()
         }
 #endif
 
-        public override DirectoryInfoBase GetParent(string path)
+        public override IDirectoryInfo GetParent(string path)
         {
             if (path == null)
             {

System.IO.Abstractions.TestingHelpers/MockDirectoryInfo.cs

@@ -127,13 +127,13 @@ public override void Create(DirectorySecurity directorySecurity)
         }
 #endif
 
-        public override DirectoryInfoBase CreateSubdirectory(string path)
+        public override IDirectoryInfo CreateSubdirectory(string path)
         {
             return mockFileDataAccessor.Directory.CreateDirectory(Path.Combine(FullName, path));
         }
 
 #if NET40
-        public override DirectoryInfoBase CreateSubdirectory(string path, DirectorySecurity directorySecurity)
+        public override IDirectoryInfo CreateSubdirectory(string path, DirectorySecurity directorySecurity)
         {
             return mockFileDataAccessor.Directory.CreateDirectory(Path.Combine(FullName, path), directorySecurity);
         }
@@ -144,47 +144,47 @@ public override void Delete(bool recursive)
             mockFileDataAccessor.Directory.Delete(directoryPath, recursive);
         }
 
-        public override IEnumerable<DirectoryInfoBase> EnumerateDirectories()
+        public override IEnumerable<IDirectoryInfo> EnumerateDirectories()
         {
             return GetDirectories();
         }
 
-        public override IEnumerable<DirectoryInfoBase> EnumerateDirectories(string searchPattern)
+        public override IEnumerable<IDirectoryInfo> EnumerateDirectories(string searchPattern)
         {
             return GetDirectories(searchPattern);
         }
 
-        public override IEnumerable<DirectoryInfoBase> EnumerateDirectories(string searchPattern, SearchOption searchOption)
+        public override IEnumerable<IDirectoryInfo> EnumerateDirectories(string searchPattern, SearchOption searchOption)
         {
             return GetDirectories(searchPattern, searchOption);
         }
 
-        public override IEnumerable<FileInfoBase> EnumerateFiles()
+        public override IEnumerable<IFileInfo> EnumerateFiles()
         {
             return GetFiles();
         }
 
-        public override IEnumerable<FileInfoBase> EnumerateFiles(string searchPattern)
+        public override IEnumerable<IFileInfo> EnumerateFiles(string searchPattern)
         {
             return GetFiles(searchPattern);
         }
 
-        public override IEnumerable<FileInfoBase> EnumerateFiles(string searchPattern, SearchOption searchOption)
+        public override IEnumerable<IFileInfo> EnumerateFiles(string searchPattern, SearchOption searchOption)
         {
             return GetFiles(searchPattern, searchOption);
         }
 
-        public override IEnumerable<FileSystemInfoBase> EnumerateFileSystemInfos()
+        public override IEnumerable<IFileSystemInfo> EnumerateFileSystemInfos()
         {
             return GetFileSystemInfos();
         }
 
-        public override IEnumerable<FileSystemInfoBase> EnumerateFileSystemInfos(string searchPattern)
+        public override IEnumerable<IFileSystemInfo> EnumerateFileSystemInfos(string searchPattern)
         {
             return GetFileSystemInfos(searchPattern);
         }
 
-        public override IEnumerable<FileSystemInfoBase> EnumerateFileSystemInfos(string searchPattern, SearchOption searchOption)
+        public override IEnumerable<IFileSystemInfo> EnumerateFileSystemInfos(string searchPattern, SearchOption searchOption)
         {
             return GetFileSystemInfos(searchPattern, searchOption);
         }
@@ -199,17 +199,17 @@ public override DirectorySecurity GetAccessControl(AccessControlSections include
             return mockFileDataAccessor.Directory.GetAccessControl(directoryPath, includeSections);
         }
 
-        public override DirectoryInfoBase[] GetDirectories()
+        public override IDirectoryInfo[] GetDirectories()
         {
             return ConvertStringsToDirectories(mockFileDataAccessor.Directory.GetDirectories(directoryPath));
         }
 
-        public override DirectoryInfoBase[] GetDirectories(string searchPattern)
+        public override IDirectoryInfo[] GetDirectories(string searchPattern)
         {
             return ConvertStringsToDirectories(mockFileDataAccessor.Directory.GetDirectories(directoryPath, searchPattern));
         }
 
-        public override DirectoryInfoBase[] GetDirectories(string searchPattern, SearchOption searchOption)
+        public override IDirectoryInfo[] GetDirectories(string searchPattern, SearchOption searchOption)
         {
             return ConvertStringsToDirectories(mockFileDataAccessor.Directory.GetDirectories(directoryPath, searchPattern, searchOption));
         }
@@ -222,41 +222,41 @@ private DirectoryInfoBase[] ConvertStringsToDirectories(IEnumerable<string> path
                 .ToArray();
         }
 
-        public override FileInfoBase[] GetFiles()
+        public override IFileInfo[] GetFiles()
         {
             return ConvertStringsToFiles(mockFileDataAccessor.Directory.GetFiles(FullName));
         }
 
-        public override FileInfoBase[] GetFiles(string searchPattern)
+        public override IFileInfo[] GetFiles(string searchPattern)
         {
             return ConvertStringsToFiles(mockFileDataAccessor.Directory.GetFiles(FullName, searchPattern));
         }
 
-        public override FileInfoBase[] GetFiles(string searchPattern, SearchOption searchOption)
+        public override IFileInfo[] GetFiles(string searchPattern, SearchOption searchOption)
         {
             return ConvertStringsToFiles(mockFileDataAccessor.Directory.GetFiles(FullName, searchPattern, searchOption));
         }
 
-        FileInfoBase[] ConvertStringsToFiles(IEnumerable<string> paths)
+        IFileInfo[] ConvertStringsToFiles(IEnumerable<string> paths)
         {
             return paths
                   .Select(mockFileDataAccessor.FileInfo.FromFileName)
                   .ToArray();
         }
 
-        public override FileSystemInfoBase[] GetFileSystemInfos()
+        public override IFileSystemInfo[] GetFileSystemInfos()
         {
             return GetFileSystemInfos("*");
         }
 
-        public override FileSystemInfoBase[] GetFileSystemInfos(string searchPattern)
+        public override IFileSystemInfo[] GetFileSystemInfos(string searchPattern)
         {
             return GetFileSystemInfos(searchPattern, SearchOption.TopDirectoryOnly);
         }
 
-        public override FileSystemInfoBase[] GetFileSystemInfos(string searchPattern, SearchOption searchOption)
+        public override IFileSystemInfo[] GetFileSystemInfos(string searchPattern, SearchOption searchOption)
         {
-            return GetDirectories(searchPattern, searchOption).OfType<FileSystemInfoBase>().Concat(GetFiles(searchPattern, searchOption)).ToArray();
+            return GetDirectories(searchPattern, searchOption).OfType<IFileSystemInfo>().Concat(GetFiles(searchPattern, searchOption)).ToArray();
         }
 
         public override void MoveTo(string destDirName)
@@ -269,15 +269,15 @@ public override void SetAccessControl(DirectorySecurity directorySecurity)
             mockFileDataAccessor.Directory.SetAccessControl(directoryPath, directorySecurity);
         }
 
-        public override DirectoryInfoBase Parent
+        public override IDirectoryInfo Parent
         {
             get
             {
                 return mockFileDataAccessor.Directory.GetParent(directoryPath);
             }
         }
 
-        public override DirectoryInfoBase Root
+        public override IDirectoryInfo Root
         {
             get
             {

System.IO.Abstractions.TestingHelpers/MockDirectoryInfoFactory.cs

@@ -10,7 +10,7 @@ public MockDirectoryInfoFactory(IMockFileDataAccessor mockFileSystem)
             this.mockFileSystem = mockFileSystem;
         }
 
-        public DirectoryInfoBase FromDirectoryName(string directoryName)
+        public IDirectoryInfo FromDirectoryName(string directoryName)
         {
             return new MockDirectoryInfo(mockFileSystem, directoryName);
         }

System.IO.Abstractions.TestingHelpers/MockDriveInfo.cs

@@ -44,7 +44,7 @@ public MockDriveInfo(IMockFileDataAccessor mockFileDataAccessor, string name) :
         public new bool IsReady { get; protected set; }
         public override string Name { get; protected set; }
 
-        public override DirectoryInfoBase RootDirectory
+        public override IDirectoryInfo RootDirectory
         {
             get
             {

System.IO.Abstractions.TestingHelpers/MockDriveInfoFactory.cs

@@ -12,7 +12,7 @@ public MockDriveInfoFactory(IMockFileDataAccessor mockFileSystem)
             this.mockFileSystem = mockFileSystem ?? throw new ArgumentNullException(nameof(mockFileSystem));
         }
 
-        public DriveInfoBase[] GetDrives()
+        public IDriveInfo[] GetDrives()
         {
             var driveLetters = new HashSet<string>(new DriveEqualityComparer(mockFileSystem));
             foreach (var path in mockFileSystem.AllPaths)
@@ -38,7 +38,7 @@ public DriveInfoBase[] GetDrives()
             return result.ToArray();
         }
 
-        public DriveInfoBase FromDriveName(string driveName)
+        public IDriveInfo FromDriveName(string driveName)
         {
             var drive = mockFileSystem.Path.GetPathRoot(driveName);