rust fmt

VS Code extension for formatting Rust code with rustfmt.

Supports:

File formatting (including format on save)
Workspace formatting (cargo fmt-optimized)
Git-aware formatting (changed / staged Rust files)
Status bar + Control Center quick actions
Native macro_rules! body formatting
Standalone binary usable from Vim / Neovim without a plugin

Requirements

rustup component add rustfmt

Works on Linux, Windows, macOS.

Settings

Setting	Default	Description
`rustfmt.path`	`"rustfmt"`	Path to rustfmt executable
`rustfmt.extraArgs`	`[]`	Additional rustfmt arguments
`rustfmt.onboarding.mode`	`"quiet"`	Onboarding mode (`quiet` / `guided`)
`macroFormatter.native`	`true`	Enable `macro_rules!` body formatting
`macroFormatter.path`	auto	Path to `rust-fmt-mf` binary

Set as default formatter in settings.json:

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

Commands

Command	Description
Format Document with rustfmt	Current file (on save)
Format Workspace with rustfmt	All Rust files in workspace
Format Changed Rust Files	Files from `git diff`
Format Staged Rust Files	Files from `git diff --cached`
Check Formatting	Report unformatted files without changing them
Open Control Center	Quick action menu
Open Logs	Output channel

Vim / Neovim

The macro formatter is a plain stdin-to-stdout filter, so no plugin is needed.

Install

Download rust-fmt-mf for your platform from the latest release, put it on your PATH, and (outside Windows) make it executable:

chmod +x rust-fmt-mf

Or build it yourself:

cargo install --git https://github.com/vremyavnikuda/rust-fmt rust-fmt-mf

Vim

autocmd FileType rust setlocal formatprg=rust-fmt-mf\ --edition\ 2021

Format the buffer with gggqG, or a selection with gq.

Neovim with conform.nvim

Preferred over formatprg: it keeps the cursor position and marks, and gives you format-on-save.

require("conform").setup({
  formatters = {
    ["rust-fmt-mf"] = {
      command = "rust-fmt-mf",
      args = { "--edition", "2021" },
      stdin = true,
    },
  },
  formatters_by_ft = { rust = { "rust-fmt-mf" } },
  format_on_save = { timeout_ms = 2000, lsp_format = "never" },
})

Options

Flag	Default	Description
`--edition`	`2021`	Rust edition passed to `rustfmt`
`--rustfmt-path`	`rustfmt`	Path to the `rustfmt` executable
`--config-path`	auto	Path to `rustfmt.toml` / `.rustfmt.toml`

rustfmt.toml and rust-toolchain.toml are picked up from the working directory upwards without any flags — rustfmt searches for its own config, and the rustup shim resolves the pinned toolchain the same way. Keep your editor's working directory inside the project and both just work.

The edition is the exception: it has to be in your editor config, because the formatter reads from stdin and never learns the file's path. A crate on a different edition fails loudly with a rustfmt parse error rather than producing wrong output — change the --edition value to match.

How it works

Runs rustfmt --emit stdout with auto-detected crate root, edition, and config. When macroFormatter.native is enabled, formats macro_rules! bodies via rust-fmt-mf (skipped by standard rustfmt).

Also detects rust-toolchain and rustfmt.toml, skips files over 2 MB.

Troubleshooting

rustfmt not found: run rustup component add rustfmt or set rustfmt.path.