Mapping a null/empty decimal value

[chris-pemberton-vital]

Using the following field map

{
                        "FieldMapType": "FieldToFieldMap",
                        "ApplyTo": [
                            "Bug",
                            "Product Backlog Item"
                        ],
                        "sourceField": "Microsoft.VSTS.Scheduling.Effort",
                        "targetField": "Custom.Totalestimate",
                        "defaultValue": null
                    }

I can't seem to map the defaultValue to a null/empty for decimal field. We don't want to use 0. If we use null/empty or omitted the defaultValue we always get:

Invalid Field Object:

{
"WorkItemId": 0,
"CurrentRevisionWorkItemRev": 0,
"CurrentRevisionWorkItemTypeName": "Bug",
"Name": "Total estimate",
"ReferenceName": "Custom.Totalestimate",
"Value": "",
"OriginalValue": null,
"ValueWithServerDefault": "",
"Status": 14,
"IsRequired": false,
"IsEditable": true,
"IsDirty": true,
"IsComputed": false,
"IsChangedByUser": true,
"IsChangedInRevision": true,
"HasPatternMatch": false,
"IsLimitedToAllowedValues": false,
"HasAllowedValuesList": false,
"AllowedValues": [],
"IdentityFieldAllowedValues": [],
"ProhibitedValues": []
}

What we want is if there is a value then map it else, null. The field is not required. Is this possible?

[chris-pemberton-vital]

In FieldToFieldMap I have made a local change to get around the issue. You may wish to do the same on the project:

var value = source.Fields[Config.sourceField]?.Value != null ? Convert.ToString(source.Fields[Config.sourceField]?.Value) : null;

Convert.ToString converts null values to empty string, if the value was null, keep as null otherwise the empty string will break a Double/Decimal field setting