coviz

coviz is a Rust 2024 command-line tool for visualizing Go and Rust source code as a call graph. It is inspired by go-callvis, but targets a smaller MVP: parse local source files, build a simple function/call relationship graph, and emit machine-readable output that other tools can render or inspect.

MVP scope

Analyze a file or directory of Go or Rust source code.
Infer language from file extensions by default, or accept an explicit language.
Emit Graphviz DOT for visualization.
Emit JSON for downstream tooling.
Keep output focused on source-level call relationships, not full compiler semantic resolution.

Install

From this repository:

cargo install --path .

From crates.io, after the package is published:

cargo install coviz

Usage

Analyze the current directory and print DOT to stdout:

coviz

Analyze a Go project and write DOT:

coviz ./examples/go --language go --format dot --output graph.dot

Render DOT with Graphviz:

dot -Tsvg graph.dot -o graph.svg

Analyze a Rust crate and write JSON:

coviz ./src --language rust --format json --output graph.json

Open a quick local browser viewer. The command writes temporary files under /tmp/coviz-*, starts a localhost server, and opens the default browser:

coviz quick ./src --language rust

When Graphviz dot is installed, quick mode renders graph.svg with Graphviz for a cleaner clustered layout. Without Graphviz, it falls back to the built-in browser renderer.

Quick mode excludes common test files, Rust #[cfg(test)] code, tests/, and target/ by default. Use --include-tests when you need those nodes.

Use automatic language detection and stdout:

coviz ./path/to/project --language auto --format json --output -

Language support

Go: .go files through tree-sitter-go.
Rust: .rs files through tree-sitter-rust.
Auto mode: infers supported languages from file extensions.

Mixed-language repositories are part of the MVP target, but language-specific analysis is intentionally lightweight. Treat generated graphs as navigation and inspection aids rather than compiler-accurate call graphs.

Development

Use the stable Rust toolchain.

cargo fmt --all -- --check
cargo clippy --all-targets --all-features -- -D warnings
cargo test --all-targets --all-features

Run the CLI locally: