[BUG] `fab exists` returns strings instead of booleans in `--output_format json`

[Guust-Franssens]

Bug Description

When output_format=json is configured (either via config file or --output_format json argument) the exists command returns boolean values as strings "true" or "false" instead of native JSON booleans. This forces the user to parse strings instead of using boolean values directly. Furthermore this can cause logic errors as "false" is truthy in conditional checks.

fab exists ws1.Workspace/lh1.Lakehouse --output_format json
{
    "timestamp": "2025-12-29T16:42:07.387900Z",
    "status": "Success",
    "command": "exists",
    "result": {
        "message": "true"
    }
}

fabric-cli version

1.3.1.

Python version

3.12.3

Operating System

Windows

CLI Mode

Command line mode

Authentication Method

Service principal (secret)

Steps to Reproduce

fab exists <workspace>/<item> --output_format json
{
    "timestamp": "2025-12-29T16:42:07.387900Z",
    "status": "Success",
    "command": "exists",
    "result": {
        "message": "true"
    }
}

Expected Behavior

fab exists <workspace>/<item> --output_format json
{
    "timestamp": "2025-12-29T16:42:07.387900Z",
    "status": "Success",
    "command": "exists",
    "result": {
        "message": true
    }
}

Actual Behavior

fab exists <workspace>/<item> --output_format json
{
    "timestamp": "2025-12-29T16:42:07.387900Z",
    "status": "Success",
    "command": "exists",
    "result": {
        "message": "true"
    }
}

Additional Context

No response

Possible Solution

No response

[aviatco]

/triaged

@Guust-Franssens
Thanks for bringing this up! The JSON object result should be consistent across all commands for easier parsing, so the message property should remain a string, and consumers should parse the result as needed.
I agree there’s room to improve the JSON response, and we’re already working on enhancements, your feedback will definitely be considered when refining the exists command.

[microsoft-github-policy-service]

Triage has been completed for this issue.