Fix exists and lenght properties in MockFileInfo.

Author: PatrykOlejniczak

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

@@ -50,6 +50,20 @@ public void MockFileInfo_Exists_ShouldReturnFalseIfFileDoesNotExistInMemoryFileS
             Assert.IsFalse(result);
         }
 
+        [Test]
+        public void MockFileInfo_Exists_ShouldRetunFalseIfPathLeadsToDirectory()
+        {
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                { XFS.Path(@"c:\a\b\c.txt"), new MockFileData("Demo text content") },
+            });
+            var fileInfo = new MockFileInfo(fileSystem, XFS.Path(@"c:\a\b"));
+
+            var result = fileInfo.Exists;
+
+            Assert.IsFalse(result);
+        }
+
         [Test]
         public void MockFileInfo_Length_ShouldReturnLengthOfFileInMemoryFileSystem()
         {
@@ -82,6 +96,21 @@ public void MockFileInfo_Length_ShouldThrowFileNotFoundExceptionIfFileDoesNotExi
             Assert.AreEqual(XFS.Path(@"c:\foo.txt"), ex.FileName);
         }
 
+        [Test]
+        public void MockFileInfo_Length_ShouldThrowFileNotFoundExceptionIfPathLeadsToDirectory()
+        {
+            const string fileContent = "Demo text content";
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                { XFS.Path(@"c:\a\b\c.txt"), new MockFileData(fileContent) },
+            });
+            var fileInfo = new MockFileInfo(fileSystem, XFS.Path(@"c:\a\b"));
+
+            var ex = Assert.Throws<FileNotFoundException>(() => fileInfo.Length.ToString(CultureInfo.InvariantCulture));
+
+            Assert.AreEqual(XFS.Path(@"c:\a\b"), ex.FileName);
+        }
+
         [Test]
         public void MockFileInfo_CreationTimeUtc_ShouldReturnCreationTimeUtcOfFileInMemoryFileSystem()
         {

System.IO.Abstractions.TestingHelpers/MockFileInfo.cs

@@ -68,7 +68,7 @@ public override DateTime CreationTimeUtc
 
         public override bool Exists
         {
-            get { return MockFileData != null; }
+            get { return MockFileData != null && !MockFileData.IsDirectory; }
         }
 
         public override string Extension
@@ -307,7 +307,7 @@ public override long Length
         {
             get
             {
-                if (MockFileData == null) throw CommonExceptions.FileNotFound(path);
+                if (MockFileData == null || MockFileData.IsDirectory) throw CommonExceptions.FileNotFound(path);
                 return MockFileData.Contents.Length;
             }
         }