Hello @Arie and welcome to Microsoft Q&A.
This is my first time meeting Bicep, but from what I understand, the issue is most likely not Bicep vs JSON. This is to say, the same configuration in the form of JSON is likely also to miss.
Data Factory and Synapse are similar. I know Data Factory allows setting up the repo integration during creation. However, I am not certain Synapse allows repo setup during creation. In search of evidence either way, I compared documentation of the two, and compared the resource creation wizard of the two. Usually all options available during creation process are exposed in the wizard.
What I found was:
- Synapse creation wizard: no repo integration options
- Data Factory creation wizard: full repo integration options
- Synapse source control document: Only mentions setting up repo integration after workspace creation. No creation-time options mentioned
- Data Factory source control document: Mentions setting up repo both during creation and after creation
Furthermore, the Synapse source control document says:
After launching your Synapse Studio, you can configure a git repository in your workspace. A Synapse Studio workspace can be associated with only one git repository at a time.
So, I am inclined to say (with 75% confidence) that Synapse does not support repo integration during the workspace creation process.
If you like, I can inquire internally for a definitive answer.