Combining a Scan with a Baseline

This guide explains how to combine a Vibgrate scan with a saved baseline so you can see what drift is new rather than just the absolute level. It is for teams that want to gate on regressions, not on the debt that already exists.

Overview

A baseline is a stored snapshot of your project's scan state. When you scan against a baseline, the CLI compares the current result to the snapshot so you can focus on changes since the baseline was taken. This is the foundation of a drift fitness function.

Step-by-step

First, capture a baseline of the current state:

vg baseline

Later, run a scan that compares against that baseline file:

vg scan --baseline .vibgrate/baseline.json

The scan reports the current DriftScore and the delta relative to the baseline.

Why compare to a baseline

• Gate on new drift so a pull request that worsens the project fails while pre-existing debt does not block everyone.
• Track progress as you pay down drift over time.
• Combine with --drift-budget for an absolute ceiling and a baseline for relative regression control.

You can also initialize a project together with a baseline using vg init --baseline.

Related

See the baseline command reference, the drift baselines and fitness functions article, the setting a drift budget guide, and the scan command reference.