Is there any way to merge fields without adding the doneMatch into the field? - azure-devops-extensions

Question

We need to merge two fields into one. In the config, there is a "doneMatch" special string, and this seems to get appended to the merged field. Why is this needed, and is there a way to not have it also appended to the target field?
For example, I have:
src.fieldA = "City"
src.fieldB = "State"
I want to merge these 2 fields into target.fieldA as "City: State". However, what I end up with is "City: State##DONE##" I can change the config file so that it uses a different doneMatch but it can't be null or empty.. so if I changed it to ";", then the resulting field would be "City: State;". I have to have an end done char/string for some reason. What is this used for? If I am synching the fields with newer updates, is it going to detect the previous ##DONE## in the target.fieldA and think it's already done the merge, so would not make any new changes?
Can someone send me more info on this feature?

Answer 1

I have updated the code for v9.0.1 that changes the way that the FieldMerge works. It no longer uses doneMatch and instead requires that all 3 fields are different and then skips if it has already been done.
if (source.Fields.Contains(config.sourceField1) && source.Fields.Contains(config.sourceField2))
{
var val1 = source.Fields[config.sourceField1].Value != null ? source.Fields[config.sourceField1].Value.ToString() : string.Empty;
var val2 = source.Fields[config.sourceField2].Value != null ? source.Fields[config.sourceField2].Value.ToString() : string.Empty;
var valT = target.Fields[config.targetField].Value != null ? target.Fields[config.targetField].Value.ToString() : string.Empty;
var newValT = string.Format(config.formatExpression, val1, val2);
if (valT.Equals(newValT))
{
Trace.WriteLine(string.Format(" [SKIP] field already merged {0}:{1}+{2} to {3}:{4}", source.Id, config.sourceField1, config.sourceField2, target.Id, config.targetField));
} else
{
target.Fields[config.targetField].Value = string.Format(config.formatExpression, val1, val2) + config.doneMatch;
Trace.WriteLine(string.Format(" [UPDATE] field merged {0}:{1}+{2} to {3}:{4}", source.Id, config.sourceField1, config.sourceField2, target.Id, config.targetField));
}
}
https://github.com/nkdAgility/azure-devops-migration-tools/pull/529

Answer 2

Test the field merge with Azure Devops Migration tools, I could also reproduce this situation. The doneMatch field is required in the configuration.json file(##Done## by default).
There seems to be no way to avoid adding donematch to the target field. Since I am not the developer of this tool, I am not sure about the function of this field.
I would like to share a workaround to solve this issue.
Workaround:
You could try to set the " " to the doneMatch field. ( "doneMatch": " ")
For example:
"FieldMaps": [
{
"ObjectType": "VstsSyncMigrator.Engine.Configuration.FieldMap.FieldMergeMapConfig",
"WorkItemTypeName": "*",
"sourceField1": "System.Description",
"sourceField2": "Microsoft.VSTS.Common.AcceptanceCriteria",
"targetField": "System.Description",
"formatExpression": "{0} {1}",
"doneMatch": " "
}
Since the configuration file is a Json file, you could use " " to represent spaces.
Result:
is it going to detect the previous ##DONE## in the target.fieldA and
think it's already done the merge, so would not make any new changes
Based on my test, the ##Done## in the target field will not affect other operations. You can still operate on this field.
Update:
The above method could only work on field type: Text (multiple lines). If the field is other types, this method doesn't work.
You could create a new field(Text (multiple lines)). Then you could set the target field as the new field.
e.g.
"FieldMaps": [
{
"ObjectType": "VstsSyncMigrator.Engine.Configuration.FieldMap.FieldMergeMapConfig",
"WorkItemTypeName": "*",
"sourceField1": "Custom.test1",
"sourceField2": "Custom.test2",
"targetField": "Custom.test3",
"formatExpression": "{0} {1}",
"doneMatch": " "
}