HDF converter crashes on "code" with null value

[Jiri-Stary]

Hello,

i tried converting some sonarqube HDF files and the converter crashes.
I can share similar sample to mine directly from mitre saf repo

https://github.com/mitre/saf/blob/main/test/sample_data/sonarqube/sonarqube-hdf.json

i can see in your HDF convert test cases you have empty strings, but mitre saf generates null values instead:

Newtonsoft.Json.JsonSerializationException: Required property 'code' expects a value but got null. Path 'profiles[0].controls[0]', line 1, position 3797.
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.EndProcessProperty(Object newObject, JsonReader reader, JsonObjectContract contract, Int32 initialDepth, JsonProperty property, PropertyPresence presence, Boolean setDefaultValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateList(IList list, JsonReader reader, JsonArrayContract contract, JsonProperty containerProperty, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateList(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, Object existingValue, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateList(IList list, JsonReader reader, JsonArrayContract contract, JsonProperty containerProperty, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateList(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, Object existingValue, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonSerializer.Deserialize(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
at Microsoft.CodeAnalysis.Sarif.Converters.HdfModel.HdfFile.FromJson(String json) in //src/Sarif.Converters/HdfModel/HdfFile.cs:line 26
at Microsoft.CodeAnalysis.Sarif.Converters.HdfConverter.Convert(Stream input, IResultLogWriter output, OptionallyEmittedData dataToInsert) in //src/Sarif.Converters/HdfConverter.cs:line 29
at Microsoft.CodeAnalysis.Sarif.Converters.ToolFormatConverter.ConvertToStandardFormat(String toolFormat, Stream inputStream, IResultLogWriter outputStream, OptionallyEmittedData dataToInsert, String pluginAssemblyPath) in //src/Sarif.Converters/ToolFormatConverter.cs:line 94
at Microsoft.CodeAnalysis.Sarif.Converters.ToolFormatConverter.ConvertToStandardFormat(String toolFormat, String inputFileName, String outputFileName, FilePersistenceOptions logFilePersistenceOptions, OptionallyEmittedData dataToInsert, String pluginAssemblyPath) in //src/Sarif.Converters/ToolFormatConverter.cs:line 62
at Microsoft.CodeAnalysis.Sarif.Multitool.ConvertCommand.Run(ConvertOptions convertOptions, IFileSystem fileSystem) in /_/src/Sarif.Multitool.Library/ConvertCommand.cs:line 55