Allow source and transform files to be read-only

Fixed microsoft#16

src/Microsoft.VisualStudio.Jdt.Tests/JsonTransformationTest.cs

@@ -275,6 +275,31 @@ public void ThrowAndLogException()
             }
         }
 
+        /// <summary>
+        /// Tests that a transformation succeeds even if the source and transform files are read-only.
+        /// </summary>
+        [Fact]
+        public void ReadOnly()
+        {
+            const string TransformSourceString = @"{
+                                                        '@jdt.rename' : {
+                                                            'A' : 'Astar'
+                                                        }
+                                                    }";
+
+            // create temporary files to use for the source and transform
+            using (ReadOnlyTempFile tempSourceFilePath = new ReadOnlyTempFile(SimpleSourceString))
+            using (ReadOnlyTempFile tempTransformFilePath = new ReadOnlyTempFile(TransformSourceString))
+            {
+                // apply transform
+                JsonTransformation transformation = new JsonTransformation(tempSourceFilePath.FilePath, this.logger);
+                using (Stream result = transformation.Apply(tempTransformFilePath.FilePath))
+                {
+                    // succeess
+                }
+            }
+        }
+
         private static void LogHasSingleEntry(List<JsonTransformationTestLogger.TestLogEntry> log, string fileName, int lineNumber, int linePosition, bool fromException)
         {
             Assert.Single(log);

src/Microsoft.VisualStudio.Jdt.Tests/ReadOnlyTempFile.cs

@@ -0,0 +1,68 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.VisualStudio.Jdt.Tests
+{
+    using System;
+    using System.IO;
+
+    /// <summary>
+    /// Read-Only Temp File.
+    /// </summary>
+    /// <seealso cref="System.IDisposable" />
+    internal class ReadOnlyTempFile : IDisposable
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ReadOnlyTempFile"/> class.
+        /// </summary>
+        /// <param name="contents">The contents.</param>
+        public ReadOnlyTempFile(string contents)
+        {
+            // create temp file
+            this.FilePath = Path.GetTempFileName();
+
+            // write contents
+            File.WriteAllText(this.FilePath, contents);
+
+            // set the file as read-only
+            File.SetAttributes(this.FilePath, FileAttributes.ReadOnly);
+        }
+
+        /// <summary>
+        /// Gets the file path.
+        /// </summary>
+        /// <value>The file path.</value>
+        public string FilePath { get; private set; }
+
+        /// <summary>
+        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+        /// </summary>
+        public void Dispose()
+        {
+            // delete file
+            if (this.FilePath == null)
+            {
+                // nothing to delete
+                return;
+            }
+
+            if (!File.Exists(this.FilePath))
+            {
+                // nothing to delete
+                return;
+            }
+
+            // remove read-only attribute if it exists
+            FileAttributes attributes = File.GetAttributes(this.FilePath);
+            if ((attributes & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)
+            {
+                // read-only attribute exists
+                // remove read-only attribute
+                File.SetAttributes(this.FilePath, attributes ^ FileAttributes.ReadOnly);
+            }
+
+            // delete the file
+            File.Delete(this.FilePath);
+        }
+    }
+}

src/Microsoft.VisualStudio.Jdt/JsonTransformation.cs

@@ -41,7 +41,7 @@ public JsonTransformation(string transformFile, IJsonTransformationLogger logger
 
             this.logger = new JsonTransformationContextLogger(transformFile, logger);
 
-            using (FileStream transformStream = File.Open(transformFile, FileMode.Open))
+            using (FileStream transformStream = File.Open(transformFile, FileMode.Open, FileAccess.Read))
             {
                 this.SetTransform(transformStream);
             }
@@ -86,7 +86,7 @@ public Stream Apply(string sourceFile)
             }
 
             // Open the file as streams and apply the transforms
-            using (Stream sourceStream = File.Open(sourceFile, FileMode.Open))
+            using (Stream sourceStream = File.Open(sourceFile, FileMode.Open, FileAccess.Read))
             {
                 return this.ApplyWithSourceName(sourceStream, sourceFile);
             }