Don't throw on empty file path. Fix #8

Author: JimBobSquarePants

src/UmbracoFileSystemProviders.Azure/AzureFileSystem.cs

@@ -220,61 +220,65 @@ public static AzureFileSystem GetInstance(string containerName, string rootUrl,
         public void AddFile(string path, Stream stream, bool overrideIfExists)
         {
             CloudBlockBlob blockBlob = this.GetBlockBlobReference(path);
-            bool exists = blockBlob.Exists();
-            DateTimeOffset created = DateTimeOffset.MinValue;
 
-            if (!overrideIfExists && exists)
+            if (blockBlob != null)
             {
-                InvalidOperationException error = new InvalidOperationException($"File already exists at {blockBlob.Uri}");
-                this.LogHelper.Error<AzureBlobFileSystem>($"File already exists at {path}", error);
-                return;
-            }
+                bool exists = blockBlob.Exists();
+                DateTimeOffset created = DateTimeOffset.MinValue;
 
-            try
-            {
-                if (exists)
+                if (!overrideIfExists && exists)
                 {
-                    // Ensure original created date is preserved.
-                    blockBlob.FetchAttributes();
-                    if (blockBlob.Metadata.ContainsKey("CreatedDate"))
+                    InvalidOperationException error = new InvalidOperationException($"File already exists at {blockBlob.Uri}");
+                    this.LogHelper.Error<AzureBlobFileSystem>($"File already exists at {path}", error);
+                    return;
+                }
+
+                try
+                {
+                    if (exists)
                     {
-                        // We store the creation date in meta data.
-                        created = DateTime.Parse(blockBlob.Metadata["CreatedDate"], CultureInfo.InvariantCulture).ToUniversalTime();
+                        // Ensure original created date is preserved.
+                        blockBlob.FetchAttributes();
+                        if (blockBlob.Metadata.ContainsKey("CreatedDate"))
+                        {
+                            // We store the creation date in meta data.
+                            created = DateTime.Parse(blockBlob.Metadata["CreatedDate"], CultureInfo.InvariantCulture).ToUniversalTime();
+                        }
                     }
-                }
 
-                blockBlob.UploadFromStream(stream);
+                    blockBlob.UploadFromStream(stream);
 
-                string contentType = this.MimeTypeResolver.Resolve(path);
+                    string contentType = this.MimeTypeResolver.Resolve(path);
 
-                if (!string.IsNullOrWhiteSpace(contentType))
-                {
-                    blockBlob.Properties.ContentType = contentType;
-                }
+                    if (!string.IsNullOrWhiteSpace(contentType))
+                    {
+                        blockBlob.Properties.ContentType = contentType;
+                    }
 
-                blockBlob.Properties.CacheControl = $"public, max-age={this.MaxDays * 86400}";
-                blockBlob.SetProperties();
+                    blockBlob.Properties.CacheControl = $"public, max-age={this.MaxDays * 86400}";
+                    blockBlob.SetProperties();
 
-                if (created == DateTimeOffset.MinValue)
-                {
-                    created = DateTimeOffset.UtcNow;
-                }
+                    if (created == DateTimeOffset.MinValue)
+                    {
+                        created = DateTimeOffset.UtcNow;
+                    }
 
-                // Store the creation date in meta data.
-                if (blockBlob.Metadata.ContainsKey("CreatedDate"))
-                {
-                    blockBlob.Metadata["CreatedDate"] = created.ToString(CultureInfo.InvariantCulture);
+                    // Store the creation date in meta data.
+                    if (blockBlob.Metadata.ContainsKey("CreatedDate"))
+                    {
+                        blockBlob.Metadata["CreatedDate"] = created.ToString(CultureInfo.InvariantCulture);
+                    }
+                    else
+                    {
+                        blockBlob.Metadata.Add("CreatedDate", created.ToString(CultureInfo.InvariantCulture));
+                    }
+
+                    blockBlob.SetMetadata();
                 }
-                else
+                catch (Exception ex)
                 {
-                    blockBlob.Metadata.Add("CreatedDate", created.ToString(CultureInfo.InvariantCulture));
+                    this.LogHelper.Error<AzureBlobFileSystem>($"Unable to upload file at {path}", ex);
                 }
-
-                blockBlob.SetMetadata();
-            }
-            catch (Exception ex)
-            {
-                this.LogHelper.Error<AzureBlobFileSystem>($"Unable to upload file at {path}", ex);
             }
         }
 
@@ -362,13 +366,16 @@ public void DeleteFile(string path)
         {
             CloudBlockBlob blockBlob = this.GetBlockBlobReference(path);
 
-            try
+            if (blockBlob != null)
             {
-                blockBlob.DeleteIfExists(DeleteSnapshotsOption.IncludeSnapshots);
-            }
-            catch (Exception ex)
-            {
-                this.LogHelper.Error<AzureBlobFileSystem>($"Unable to delete file at {path}", ex);
+                try
+                {
+                    blockBlob.DeleteIfExists(DeleteSnapshotsOption.IncludeSnapshots);
+                }
+                catch (Exception ex)
+                {
+                    this.LogHelper.Error<AzureBlobFileSystem>($"Unable to delete file at {path}", ex);
+                }
             }
         }
 
@@ -396,7 +403,8 @@ public bool DirectoryExists(string path)
         /// </returns>
         public bool FileExists(string path)
         {
-            return this.GetBlockBlobReference(path).Exists();
+            CloudBlockBlob blockBlobReference = this.GetBlockBlobReference(path);
+            return blockBlobReference?.Exists() ?? false;
         }
 
         /// <summary>
@@ -410,12 +418,15 @@ public DateTimeOffset GetCreated(string path)
         {
             CloudBlockBlob blockBlob = this.GetBlockBlobReference(path);
 
-            // Populate the blob's attributes.
-            blockBlob.FetchAttributes();
-            if (blockBlob.Metadata.ContainsKey("CreatedDate"))
+            if (blockBlob != null)
             {
-                // We store the creation date in meta data.
-                return DateTimeOffset.Parse(blockBlob.Metadata["CreatedDate"], CultureInfo.InvariantCulture).ToUniversalTime();
+                // Populate the blob's attributes.
+                blockBlob.FetchAttributes();
+                if (blockBlob.Metadata.ContainsKey("CreatedDate"))
+                {
+                    // We store the creation date in meta data.
+                    return DateTimeOffset.Parse(blockBlob.Metadata["CreatedDate"], CultureInfo.InvariantCulture).ToUniversalTime();
+                }
             }
 
             return DateTimeOffset.MinValue;
@@ -504,12 +515,18 @@ public string GetFullPath(string path)
         public DateTimeOffset GetLastModified(string path)
         {
             CloudBlockBlob blockBlob = this.GetBlockBlobReference(path);
-            blockBlob.FetchAttributes();
-            return blockBlob.Properties.LastModified.GetValueOrDefault();
+
+            if (blockBlob != null)
+            {
+                blockBlob.FetchAttributes();
+                return blockBlob.Properties.LastModified.GetValueOrDefault();
+            }
+
+            return DateTimeOffset.MinValue;
         }
 
         /// <summary>
-        /// Returns the relative path to the media item.
+        /// Returns the application relative path to the file.
         /// </summary>
         /// <param name="fullPathOrUrl">The full path or url.</param>
         /// <returns>
@@ -521,7 +538,7 @@ public string GetRelativePath(string fullPathOrUrl)
         }
 
         /// <summary>
-        /// Returns the url to the media item.
+        /// Returns the application relative url to the file.
         /// </summary>
         /// <remarks>If the virtual path provider is enabled this returns a relative url.</remarks>
         /// <param name="path">The path to return the url for.</param>
@@ -539,32 +556,36 @@ public string GetUrl(string path)
         }
 
         /// <summary>
-        /// Gets a <see cref="Stream"/> containing the contains of the given file.
+        /// Gets a <see cref="Stream"/> representing the file at the gieven path.
         /// </summary>
         /// <param name="path">The path to the file.</param>
         /// <returns>
         /// <see cref="Stream"/>.
         /// </returns>
         public Stream OpenFile(string path)
         {
-            // TODO: Caching?
             CloudBlockBlob blockBlob = this.GetBlockBlobReference(path);
 
-            if (!blockBlob.Exists())
+            if (blockBlob != null)
             {
-                this.LogHelper.Info<AzureBlobFileSystem>($"No file exists at {path}.");
-                return null;
-            }
+                if (!blockBlob.Exists())
+                {
+                    this.LogHelper.Info<AzureBlobFileSystem>($"No file exists at {path}.");
+                    return null;
+                }
 
-            MemoryStream stream = new MemoryStream();
-            blockBlob.DownloadToStream(stream);
+                MemoryStream stream = new MemoryStream();
+                blockBlob.DownloadToStream(stream);
 
-            if (stream.CanSeek)
-            {
-                stream.Seek(0, SeekOrigin.Begin);
+                if (stream.CanSeek)
+                {
+                    stream.Seek(0, SeekOrigin.Begin);
+                }
+
+                return stream;
             }
 
-            return stream;
+            return null;
         }
 
         /// <summary>
@@ -601,7 +622,12 @@ private static CloudBlobContainer CreateContainer(CloudBlobClient cloudBlobClien
         private CloudBlockBlob GetBlockBlobReference(string path)
         {
             string blobPath = this.FixPath(path);
-            return this.cloudBlobContainer.GetBlockBlobReference(blobPath);
+
+            // Only make the request if there is an actual path. See issue 8.
+            // https://github.com/JimBobSquarePants/UmbracoFileSystemProviders.Azure/issues/8
+            return !string.IsNullOrWhiteSpace(path)
+                ? this.cloudBlobContainer.GetBlockBlobReference(blobPath)
+                : null;
         }
 
         /// <summary>