[Storage][Functions] Fix blob trigger message serialization (Azure#24032)

* fix zero length file download.

* re-record.

* make sure track 1 and track 2 use same format.

* changelog.

* ignore case.

Author: kasobol-msft

sdk/storage/Microsoft.Azure.WebJobs.Extensions.Storage.Blobs/CHANGELOG.md

@@ -1,7 +1,7 @@
 # Release History
 
 ## 5.0.0-beta.6 (Unreleased)
-
+- Fixed bug where internal message format of blob trigger didn't interop with previous major versions of the extension.
 
 ## 5.0.0-beta.5 (2021-07-09)
 - This release contains bug fixes to improve quality.

sdk/storage/Microsoft.Azure.WebJobs.Extensions.Storage.Blobs/src/Listeners/BlobTriggerMessage.cs

@@ -1,10 +1,10 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+using System;
 using System.Diagnostics.CodeAnalysis;
 using Azure.Storage.Blobs.Models;
 using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
 
 namespace Microsoft.Azure.WebJobs.Extensions.Storage.Blobs.Listeners
 {
@@ -21,10 +21,25 @@ public string Type
 
         public string FunctionId { get; set; }
 
-        // $$$ Ignored this?
-        [JsonConverter(typeof(StringEnumConverter))]
+        // See BlobTypeInternal for exact serialization.
+        [JsonIgnore]
         public BlobType BlobType { get; set; }
 
+        // BlobType enum have different values in track 2 vs track 1, e.g. Block vs BlockBlob.
+        // This internal property makes sure we serialize new type same way track 1 extension did.
+        // This also makes sure we can read both formats since we already shipped few betas and don't want to disturb them.
+        [JsonProperty("BlobType")]
+        private string BlobTypeInternal {
+            get
+            {
+                return BlobType.ToString() + "Blob";
+            }
+            set
+            {
+                BlobType = (BlobType)Enum.Parse(typeof(BlobType), value.Replace("Blob", ""), true);
+            }
+        }
+
         public string ContainerName { get; set; }
 
         public string BlobName { get; set; }

sdk/storage/Microsoft.Azure.WebJobs.Extensions.Storage.Blobs/tests/BlobTriggerMessageTests.cs

@@ -0,0 +1,70 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+namespace Microsoft.Azure.WebJobs.Extensions.Storage.Blobs.Tests
+{
+    using global::Azure.Storage.Blobs.Models;
+    using Microsoft.Azure.WebJobs.Extensions.Storage.Blobs.Listeners;
+    using Newtonsoft.Json;
+    using NUnit.Framework;
+
+    public class BlobTriggerMessageTests
+    {
+        [TestCase("containerName", "blobName", BlobType.Block, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"BlockBlob\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        [TestCase("containerName", "blobName", BlobType.Append, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"AppendBlob\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        [TestCase("containerName", "blobName", BlobType.Page, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"PageBlob\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        public void CanSerializeBlobTriggerMessage(string containerName, string blobName, BlobType blobType, string etag, string functionId, string expectedMessage)
+        {
+            var message = new BlobTriggerMessage()
+            {
+                ContainerName = containerName,
+                BlobName = blobName,
+                BlobType = blobType,
+                ETag = etag,
+                FunctionId = functionId,
+            };
+
+            var serializedMessage = JsonConvert.SerializeObject(message, Formatting.None);
+
+            Assert.AreEqual(expectedMessage, serializedMessage);
+        }
+
+        [TestCase("containerName", "blobName", BlobType.Block, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"Block\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        [TestCase("containerName", "blobName", BlobType.Append, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"Append\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        [TestCase("containerName", "blobName", BlobType.Page, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"Page\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        public void CanDeserializeBlobTriggerMessage(string containerName, string blobName, BlobType blobType, string etag, string functionId, string incomingMessage)
+        {
+            var message = JsonConvert.DeserializeObject<BlobTriggerMessage>(incomingMessage);
+
+            Assert.AreEqual(containerName, message.ContainerName);
+            Assert.AreEqual(blobName, message.BlobName);
+            Assert.AreEqual(blobType, message.BlobType);
+            Assert.AreEqual(etag, message.ETag);
+            Assert.AreEqual(functionId, message.FunctionId);
+        }
+
+        // In track 1 BlobType enum had different values.
+        [TestCase("containerName", "blobName", BlobType.Block, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"BlockBlob\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        [TestCase("containerName", "blobName", BlobType.Append, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"AppendBlob\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        [TestCase("containerName", "blobName", BlobType.Page, "etag", "functionId",
+            "{\"Type\":\"BlobTrigger\",\"FunctionId\":\"functionId\",\"BlobType\":\"PageBlob\",\"ContainerName\":\"containerName\",\"BlobName\":\"blobName\",\"ETag\":\"etag\"}")]
+        public void CanDeserializeTrack1BlobTriggerMessage(string containerName, string blobName, BlobType blobType, string etag, string functionId, string incomingMessage)
+        {
+            var message = JsonConvert.DeserializeObject<BlobTriggerMessage>(incomingMessage);
+
+            Assert.AreEqual(containerName, message.ContainerName);
+            Assert.AreEqual(blobName, message.BlobName);
+            Assert.AreEqual(blobType, message.BlobType);
+            Assert.AreEqual(etag, message.ETag);
+            Assert.AreEqual(functionId, message.FunctionId);
+        }
+    }
+}