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:

cargo run -- ./src --language rust --format dot
cargo run -- ./src --language rust --format json