Added test to verify the TransactionId HeadDocumentHeader value.

Moved the TransactionId header string to a constant class.

fix ArangoDB-Community#322

arangodb-net-standard.Test/CursorApi/CursorApiClientTest.cs

@@ -246,7 +246,6 @@ public async Task PostCursorAsync_ShouldUseHeaderProperties()
                     return Task.FromResult(mockResponse.Object);
                 });
 
-            string transactionHeaderKey = "x-arango-trx-id";
             string dummyTransactionId = "dummy transaction Id";
 
             // Call the method to create the cursor.
@@ -264,8 +263,8 @@ await apiClient.PostCursorAsync<MyModel>(
 
             // Check that the header and values are there.
             Assert.NotNull(requestHeader);
-            Assert.Contains(transactionHeaderKey, requestHeader.AllKeys);
-            Assert.Equal(dummyTransactionId, requestHeader.Get(transactionHeaderKey));
+            Assert.Contains(CustomHttpHeaders.StreamTransactionHeader, requestHeader.AllKeys);
+            Assert.Equal(dummyTransactionId, requestHeader.Get(CustomHttpHeaders.StreamTransactionHeader));
         }
 
         [Fact]

arangodb-net-standard.Test/DocumentApi/DocumentApiClientTest.cs

@@ -6,6 +6,7 @@
 using ArangoDBNetStandard;
 using ArangoDBNetStandard.DocumentApi;
 using ArangoDBNetStandard.DocumentApi.Models;
+using ArangoDBNetStandard.TransactionApi.Models;
 using ArangoDBNetStandard.Transport;
 using ArangoDBNetStandardTest.DocumentApi.Models;
 using Moq;
@@ -1086,6 +1087,55 @@ public async Task ReadDocumentHeaderAsync_ShouldReturnPreconditionFailed_WhenIfM
             Assert.NotEqual($"\"{docResponse._rev}\"", response.Etag.Tag);
         }
 
+        [Fact]
+        public async Task ReadDocumentHeaderAsync_ShouldReturnOk_WhenTransactionIdIsGivenAndIsTheSame()
+        {
+            // Post a single document.
+            var docResponse =
+                await _docClient.PostDocumentAsync(_testCollection, new Dictionary<string, object> { ["key"] = "value" });
+
+            // Begin a transaction.
+            var beginTransaction = await _adb.Transaction.BeginTransaction(
+                new StreamTransactionBody
+                {
+                    Collections = new PostTransactionRequestCollections
+                    {
+                        Write = new[] { _testCollection }
+                    }
+                });
+
+            // Get the header fields.
+            var response = await _docClient.HeadDocumentAsync(
+                _testCollection,
+                docResponse._key,
+                new HeadDocumentHeader { TransactionId = beginTransaction.Result.Id });
+
+            // Check for the expected status.
+            Assert.Equal(HttpStatusCode.OK, response.Code);
+
+            // Abort the transaction.
+            await _adb.Transaction.AbortTransaction(beginTransaction.Result.Id);
+        }
+
+        [Fact]
+        public async Task ReadDocumentHeaderAsync_ShouldReturnNotFound_WhenTransctionIdIsGiveAndIsNotTheSame()
+        {
+            string dummyTransactionId = "Bogus transaction Id";
+
+            // Post a single document.
+            var docResponse =
+                await _docClient.PostDocumentAsync(_testCollection, new Dictionary<string, object> { ["key"] = "value" });
+
+            // Get the header fields.
+            var response = await _docClient.HeadDocumentAsync(
+                _testCollection,
+                docResponse._key,
+                new HeadDocumentHeader { TransactionId = dummyTransactionId });
+
+            // Check for the expected status.
+            Assert.Equal(HttpStatusCode.BadRequest, response.Code);
+        }
+
         [Fact]
         public async Task ReadDocumentHeaderAsync_ShouldReturnNotFound_WhenCollectionDoesNotExist()
         {

arangodb-net-standard/CursorApi/CursorApiClient.cs

@@ -57,7 +57,7 @@ protected virtual WebHeaderCollection GetHeaderCollection(CursorHeaderProperties
             {
                 if (!string.IsNullOrWhiteSpace(headerProperties.TransactionId))
                 {
-                    headerCollection.Add("x-arango-trx-id", headerProperties.TransactionId);
+                    headerCollection.Add(CustomHttpHeaders.StreamTransactionHeader, headerProperties.TransactionId);
                 }
             }
 

arangodb-net-standard/CustomHttpHeaders.cs

@@ -0,0 +1,13 @@
+namespace ArangoDBNetStandard
+{
+    /// <summary>
+    /// The custom HttpHeaders that may be specified in a client request.
+    /// </summary>
+    public static class CustomHttpHeaders
+    {
+        /// <summary>
+        /// The header string used for Stream Transaction.
+        /// </summary>    
+        public const string StreamTransactionHeader = "x-arango-trx-id";
+    }
+}

arangodb-net-standard/DocumentApi/DocumentApiClient.cs

@@ -666,6 +666,7 @@ public virtual async Task<PatchDocumentResponse<U>> PatchDocumentAsync<T, U>(
         /// <remarks>
         /// 200: is returned if the document was found. 
         /// 304: is returned if the “If-None-Match” header is given and the document has the same version. 
+        /// 400: is returned if the "TransactionId" header is given and the transactionId does not exist.
         /// 404: is returned if the document or collection was not found. 
         /// 412: is returned if an “If-Match” header is given and the found document has a different version. The response will also contain the found document’s current revision in the Etag header.
         /// </remarks>
@@ -692,6 +693,7 @@ public virtual async Task<HeadDocumentResponse> HeadDocumentAsync(
         /// <remarks>
         /// 200: is returned if the document was found. 
         /// 304: is returned if the “If-None-Match” header is given and the document has the same version. 
+        /// 400: is returned if the "TransactionId" header is given and the transactionId does not exist.
         /// 404: is returned if the document or collection was not found. 
         /// 412: is returned if an “If-Match” header is given and the found document has a different version. The response will also contain the found document’s current revision in the Etag header.
         /// </remarks>

arangodb-net-standard/DocumentApi/IDocumentApiClient.cs

@@ -360,6 +360,7 @@ Task<PatchDocumentResponse<U>> PatchDocumentAsync<T, U>(
         /// <remarks>
         /// 200: is returned if the document was found. 
         /// 304: is returned if the “If-None-Match” header is given and the document has the same version. 
+        /// 400: is returned if the "TransactionId" header is given and the transactionId does not exist.
         /// 404: is returned if the document or collection was not found. 
         /// 412: is returned if an “If-Match” header is given and the found document has a different version. The response will also contain the found document’s current revision in the Etag header.
         /// </remarks>
@@ -381,6 +382,7 @@ Task<HeadDocumentResponse> HeadDocumentAsync(
         /// <remarks>
         /// 200: is returned if the document was found. 
         /// 304: is returned if the “If-None-Match” header is given and the document has the same version. 
+        /// 400: is returned if the "TransactionId" header is given and the transactionId does not exist.
         /// 404: is returned if the document or collection was not found. 
         /// 412: is returned if an “If-Match” header is given and the found document has a different version. The response will also contain the found document’s current revision in the Etag header.
         /// </remarks>

arangodb-net-standard/DocumentApi/Models/HeadDocumentHeader.cs

@@ -28,7 +28,7 @@ public WebHeaderCollection ToWebHeaderCollection()
 
             if (TransactionId != null)
             {
-                collection.Add("x-arango-trx-id", TransactionId);
+                collection.Add(CustomHttpHeaders.StreamTransactionHeader, TransactionId);
             }
 
             return collection;