Add implementation of MockFileInfo.OpenText

Author: Dirk Rombauts

TestHelpers.Tests/MockFileInfoTests.cs

@@ -206,5 +206,23 @@ public void MockFileInfo_OpenRead_ShouldReturnByteContentOfFile()
 
             Assert.AreEqual(new byte[] { 1, 2 }, result);
         }
+
+        [Test]
+        public void MockFileInfo_OpenText_ShouldReturnStringContentOfFile()
+        {
+          // Arrange
+          var fileSystem = new MockFileSystem();
+          fileSystem.AddFile(@"c:\temp\file.txt", new MockFileData(@"line 1\r\nline 2"));
+          var fileInfo = fileSystem.FileInfo.FromFileName(@"c:\temp\file.txt");
+
+          // Act
+          string result;
+          using (var streamReader = fileInfo.OpenText())
+          {
+            result = streamReader.ReadToEnd();
+          }
+
+          Assert.AreEqual(@"line 1\r\nline 2", result);
+        }
     }
 }

TestingHelpers/MockFileInfo.cs

@@ -190,7 +190,7 @@ public override Stream OpenRead()
 
         public override StreamReader OpenText()
         {
-            throw new NotImplementedException("This test helper hasn't been implemented yet. They are implemented on an as-needed basis. As it seems like you need it, now would be a great time to send us a pull request over at https://github.com/tathamoddie/System.IO.Abstractions. You know, because it's open source and all.");
+          return new StreamReader(OpenRead());
         }
 
         public override Stream OpenWrite()