impact
Predict which files are affected by a change to a target file or function.
Synopsis
bobbin impact [OPTIONS] <TARGET>
Description
The impact command combines git co-change coupling, semantic similarity, and dependency signals to predict which files would be affected if you change a target file or function. It produces a ranked list of impacted files with signal attribution.
Use --depth for transitive expansion: at depth 2+, the command also checks the impact of impacted files, widening the blast radius estimate.
Options
| Option | Short | Default | Description |
|---|---|---|---|
--path <DIR> | . | Directory to analyze | |
--depth <N> | -d | 1 | Transitive impact depth (1–3) |
--mode <MODE> | -m | combined | Signal mode: combined, coupling, semantic, deps |
--limit <N> | -n | 15 | Maximum number of results |
--threshold <SCORE> | -t | 0.1 | Minimum impact score (0.0–1.0) |
--repo <NAME> | -r | Filter to a specific repository |
Examples
Show files impacted by changing a file:
bobbin impact src/auth/middleware.rs
Show transitive impact (depth 2):
bobbin impact src/auth/middleware.rs --depth 2
Use only coupling signal:
bobbin impact src/auth/middleware.rs --mode coupling
JSON output:
bobbin impact src/auth/middleware.rs --json
Prerequisites
Requires a bobbin index and a git repository. Run bobbin init and bobbin index first.