# Rust/codex-rs

In the codex-rs folder where the rust code lives:

- Crate names are prefixed with `codex-`. For examole, the `core` folder's crate is named `codex-core`
- When using format! and you can inline variables into {}, always do that.
- Never add or modify any code related to `CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR` or `CODEX_SANDBOX_ENV_VAR`.
  - You operate in a sandbox where `CODEX_SANDBOX_NETWORK_DISABLED=1` will be set whenever you use the `shell` tool. Any existing code that uses `CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR` was authored with this fact in mind. It is often used to early exit out of tests that the author knew you would not be able to run given your sandbox limitations.
  - Similarly, when you spawn a process using Seatbelt (`/usr/bin/sandbox-exec`), `CODEX_SANDBOX=seatbelt` will be set on the child process. Integration tests that want to run Seatbelt themselves cannot be run under Seatbelt, so checks for `CODEX_SANDBOX=seatbelt` are also often used to early exit out of tests, as appropriate.

Before finalizing a change to `codex-rs`, run `just fmt` (in `codex-rs` directory) to format the code and `just fix` (in `codex-rs` directory) to fix any linter issues in the code. Additionally, run the tests:
1. Run the test for the specific project that was changed. For example, if changes were made in `codex-rs/tui`, run `cargo test -p codex-tui`.
2. Once those pass, if any changes were made in common, core, or protocol, run the complete test suite with `cargo test --all-features`.

## TUI code conventions

- Use concise styling helpers from ratatui’s Stylize trait.
  - Basic spans: use "text".into()
  - Styled spans: use "text".red(), "text".green(), "text".magenta(), "text".dim(), etc.
  - Prefer these over constructing styles with `Span::styled` and `Style` directly.
  - Example: patch summary file lines
    - Desired: vec!["  └ ".into(), "M".red(), " ".dim(), "tui/src/app.rs".dim()]

## Snapshot tests

This repo uses snapshot tests (via `insta`), especially in `codex-rs/tui`, to validate rendered output. When UI or text output changes intentionally, update the snapshots as follows:

- Run tests to generate any updated snapshots:
  - `cargo test -p codex-tui`
- Check what’s pending:
  - `cargo insta pending-snapshots -p codex-tui`
- Review changes by reading the generated `*.snap.new` files directly in the repo, or preview a specific file:
  - `cargo insta show -p codex-tui path/to/file.snap.new`
- Only if you intend to accept all new snapshots in this crate, run:
  - `cargo insta accept -p codex-tui`

If you don’t have the tool:
- `cargo install cargo-insta`