rust fmt

Simple VS Code extension for formatting Rust code using rustfmt.

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Requirements

You need rustfmt installed. Install it via:

rustup component add rustfmt

Verify installation:

rustfmt --version
rustc --version
rustup --version

Works on Linux, Windows, and macOS. If your project uses rust-toolchain files, rustup is required so the extension can pick the correct toolchain. For faster workspace formatting, cargo must be available (usually installed with Rust/rustup).

VS Code Settings

Add to your settings.json and set rust-fmt as the default formatter for Rust:

"[rust]": {
    "editor.defaultFormatter": "vremyavnikuda.rust-fmt",
    "editor.formatOnSave": true
}

Extension Settings

• rustfmt.path: Path to rustfmt executable (default: "rustfmt")
• rustfmt.extraArgs: Additional arguments for rustfmt (default: [])

Usage

Automatic: Save any .rs file (if formatOnSave is enabled).

Manual:

• Command Palette (Ctrl+Shift+P / Cmd+Shift+P) -> "Format Document with rustfmt" (current file)
• Command Palette (Ctrl+Shift+P / Cmd+Shift+P) -> "Format Workspace with rustfmt" (all Rust files; uses cargo fmt when all files are saved)
• Command Palette (Ctrl+Shift+P / Cmd+Shift+P) -> "Use rust-fmt as Default Formatter" (prompts for Global or Workspace, then enables format on save)
• Shortcut: Shift+Alt+F (Windows/Linux) or Shift+Option+F (Mac) formats the entire workspace when a Rust file is active
• Status bar: "rust-fmt: active" appears for Rust files; click to format workspace

How it works

The extension runs rustfmt --emit stdout on your code and applies the formatted result.

It also:

• Sets the working directory to the nearest Cargo.toml (crate root).
• Reads edition from Cargo.toml and passes --edition.
• Finds rustfmt.toml / .rustfmt.toml and passes --config-path.
• If rust-toolchain(.toml) is present, sets RUSTUP_TOOLCHAIN automatically.
• Skips files larger than 2 MB.
• Uses cargo fmt per crate when formatting the workspace and all Rust files are saved; otherwise it falls back to per-file formatting and skips dirty files.

Troubleshooting

• rustfmt not found: install it via rustup component add rustfmt or set rustfmt.path to the executable.