force:source:retrieve add append mode or star operator.

[PawelWozniak]

What are you trying to do
Today I tried to download newly created workflow rule by using:

sfdx force:source:retrieve -m "WorkflowRule:Case.MyRule"
sfdx force:source:retrieve -m "WorkflowAlert:Case.MyEmailAlert"

And found out that those commands are overwriting the same file Case.workflow-meta.xml so or I have Rule or Alert there.
Then I executed both together -m "WorkflowRule:Case.MyRule, WorkflowAlert:Case.MyEmailAlert" and got both in that file.
However this still an issue when you have larger number of workflow rules as this will overwrite xml file with only those retrived metadata.

Describe the solution you'd like
I would like to have append mode so in case that I have already Case.workflow-meta.xml file with some rules by running sfdx command I want to append at the end my newly created WR.

Describe alternatives you've considered
As an alternative I would like to use star operator.
sfdx force:source:retrieve -m "WorkflowRule:Case.*"
in order to get all rules in this file so git can figure out what is new. Assuming that order of rules won't be mixed.

Additional context
Finally i solved that by using code below which downloaded all WRs with their actions.

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
    <version>51.0</version>
    <types>
        <members>Case</members>
        <name>Workflow</name>
    </types>
</Package>

The same issue is with Custom Labels where retrieving one is overwriting whole file.

[git2gus]

This issue has been linked to a new work item: W-8907261

[github-actions]

Thank you for filing this feature request. We appreciate your feedback and will review the feature at our next grooming or sprint planning session. We prioritize feature requests with more upvotes and comments.

[WillieRuemmele]

duplicated and tracked here : #2363