Fix for stored procedure empty cell bug

src/Core/Resolvers/QueryExecutor.cs

@@ -740,6 +740,12 @@ internal int StreamCharData(DbDataReader dbDataReader, long availableSize, Strin
             // else we throw exception.
             ValidateSize(availableSize, resultFieldSize);
 
+            // If the cell is empty, don't append anything to the resultJsonString and return 0.
+            if (resultFieldSize == 0)
+            {
+                return 0;
+            }
+
             char[] buffer = new char[resultFieldSize];
 
             // read entire field into buffer and reduce available size.
@@ -766,6 +772,13 @@ internal int StreamByteData(DbDataReader dbDataReader, long availableSize, int o
             // else we throw exception.
             ValidateSize(availableSize, resultFieldSize);
 
+            // If the cell is empty, set resultBytes to an empty array and return 0.
+            if (resultFieldSize == 0)
+            {
+                resultBytes = Array.Empty<byte>();
+                return 0;
+            }
+
             resultBytes = new byte[resultFieldSize];
 
             dbDataReader.GetBytes(ordinal: ordinal, dataOffset: 0, buffer: resultBytes, bufferOffset: 0, length: resultBytes.Length);

src/Service.Tests/DatabaseSchema-MsSql.sql

@@ -531,7 +531,8 @@ VALUES (1, 'Awesome book', 1234),
 (17, 'CONN%_CONN', 1234),
 (18, '[Special Book]', 1234),
 (19, 'ME\YOU', 1234),
-(20, 'C:\\LIFE', 1234);
+(20, 'C:\\LIFE', 1234),
+(21, '', 1234);
 SET IDENTITY_INSERT books OFF
 
 SET IDENTITY_INSERT books_mm ON

src/Service.Tests/SqlTests/GraphQLMutationTests/GraphQLMutationTestBase.cs

@@ -244,7 +244,7 @@ public async Task TestStoredProcedureMutationForInsertion(string dbQuery)
         /// <code>Check: </code> If the intended book is deleted from the DB and
         /// verifies the response.
         /// </summary>
-        public async Task TestStoredProcedureMutationForDeletion(string dbQueryToVerifyDeletion)
+        public async Task TestStoredProcedureMutationForDeletion(string dbQueryToVerifyDeletion, int expectedOriginalMaxId, int expectedFinalMaxId)
         {
             string graphQLMutationName = "executeDeleteLastInsertedBook";
             string graphQLMutation = @"
@@ -257,7 +257,7 @@ public async Task TestStoredProcedureMutationForDeletion(string dbQueryToVerifyD
 
             string currentDbResponse = await GetDatabaseResultAsync(dbQueryToVerifyDeletion);
             JsonDocument currentResult = JsonDocument.Parse(currentDbResponse);
-            Assert.AreEqual(currentResult.RootElement.GetProperty("maxId").GetInt64(), 20);
+            Assert.AreEqual(currentResult.RootElement.GetProperty("maxId").GetInt64(), expectedOriginalMaxId);
             JsonElement graphQLResponse = await ExecuteGraphQLRequestAsync(graphQLMutation, graphQLMutationName, isAuthenticated: true);
 
             // Stored Procedure didn't return anything
@@ -266,7 +266,7 @@ public async Task TestStoredProcedureMutationForDeletion(string dbQueryToVerifyD
             // check to verify new element is inserted
             string updatedDbResponse = await GetDatabaseResultAsync(dbQueryToVerifyDeletion);
             JsonDocument updatedResult = JsonDocument.Parse(updatedDbResponse);
-            Assert.AreEqual(updatedResult.RootElement.GetProperty("maxId").GetInt64(), 19);
+            Assert.AreEqual(updatedResult.RootElement.GetProperty("maxId").GetInt64(), expectedFinalMaxId);
         }
 
         public async Task InsertMutationOnTableWithTriggerWithNonAutoGenPK(string dbQuery)

src/Service.Tests/SqlTests/GraphQLMutationTests/MsSqlGraphQLMutationTests.cs

@@ -259,7 +259,7 @@ FROM [books] AS [table0]
                     WITHOUT_ARRAY_WRAPPER
             ";
 
-            await TestStoredProcedureMutationForDeletion(dbQueryToVerifyDeletion);
+            await TestStoredProcedureMutationForDeletion(dbQueryToVerifyDeletion, 21, 20);
         }
 
         /// <summary>