codex/prs/bolinfest/study/PR-1582-study.md

DOs

• Bold: Use VS Code rust-analyzer + rustfmt settings aligned with the repo.

// .vscode/settings.json
{
  "rust-analyzer.checkOnSave": true,
  "rust-analyzer.check.command": "clippy",
  "rust-analyzer.check.extraArgs": ["--all-features", "--tests"],
  "rust-analyzer.rustfmt.extraArgs": ["--config", "imports_granularity=Item"],
  "[rust]": {
    "editor.defaultFormatter": "rust-lang.rust-analyzer",
    "editor.formatOnSave": true
  }
}

• Bold: Enforce item-level import formatting (what the rustfmt arg does).

// Before (collapsed)
use std::collections::{HashMap, HashSet};

// After (Item granularity)
use std::collections::HashMap;
use std::collections::HashSet;

• Bold: Use just tasks for formatting and lint fixes.

# From codex-rs/
just fmt
just fix -p codex-tui    # or the crate you changed

• Bold: Run tests to verify changes.

# Test the changed crate first
cargo test -p codex-tui

# If you touched common/core/protocol, run the full suite
cargo test --all-features

• Bold: End files with a trailing newline.

 // Good: editor adds a final newline automatically
 {
   "some": "json"
 }
+

DON’Ts

• Bold: Don’t switch instructions or tooling to make—stick with the justfile.

// Bad (don’t add to AGENTS.md)
After changes, run `make format` and `make fix`.

// Good
After changes, run `just fmt` and `just fix -p <project>`.

• Bold: Don’t omit the rustfmt extra arg—imports won’t match project style.

// Bad: missing rust-analyzer.rustfmt.extraArgs
{
  "rust-analyzer.checkOnSave": true,
  "rust-analyzer.check.command": "clippy",
  "rust-analyzer.check.extraArgs": ["--all-features", "--tests"]
}

• Bold: Don’t leave files without a final newline.

 {
   "some": "json"
-}
\ No newline at end of file
+}

• Bold: Don’t rely on default import grouping when the repo specifies Item granularity.

// Bad
use crate::{api, config, ui};

// Good
use crate::api;
use crate::config;
use crate::ui;