-# rustfmt [](https://travis-ci.org/rust-lang-nursery/rustfmt) [](https://ci.appveyor.com/project/nrc/rustfmt) [](https://crates.io/crates/rustfmt-nightly) [](https://travis-ci.org/davidalber/rustfmt-travis)
+# rustfmt [](https://travis-ci.com/rust-lang/rustfmt) [](https://ci.appveyor.com/project/rust-lang-libs/rustfmt) [](https://crates.io/crates/rustfmt-nightly) [](https://travis-ci.org/davidalber/rustfmt-travis)
A tool for formatting Rust code according to style guidelines.
You can run `rustfmt` with Rust 1.24 and above.
+### On the Stable toolchain
+
To install:
-```
-rustup component add rustfmt-preview
+```sh
+rustup component add rustfmt
```
-to run on a cargo project in the current working directory:
+To run on a cargo project in the current working directory:
-```
+```sh
cargo fmt
```
-For the latest and greatest `rustfmt` (nightly required):
-```
-rustup component add rustfmt-preview --toolchain nightly
-```
-To run:
-```
-cargo +nightly fmt
+### On the Nightly toolchain
+
+For the latest and greatest `rustfmt`, nightly is required.
+
+To install:
+
+```sh
+rustup component add rustfmt --toolchain nightly
```
-To format code that requires edition 2018, create a `rustfmt.toml` [configuration](#configuring-rustfmt) file containing:
+To run on a cargo project in the current working directory:
-```toml
-edition = "2018"
+```sh
+cargo +nightly fmt
```
## Limitations
-Rustfmt tries to work on as much Rust code as possible, sometimes, the code
-doesn't even need to compile! As we approach a 1.0 release we are also looking
-to limit areas of instability; in particular, post-1.0, the formatting of most
-code should not change as Rustfmt improves. However, there are some things that
-Rustfmt can't do or can't do well (and thus where formatting might change
-significantly, even post-1.0). We would like to reduce the list of limitations
-over time.
+Rustfmt tries to work on as much Rust code as possible. Sometimes, the code
+doesn't even need to compile! In general, we are looking to limit areas of
+instability; in particular, post-1.0, the formatting of most code should not
+change as Rustfmt improves. However, there are some things that Rustfmt can't
+do or can't do well (and thus where formatting might change significantly,
+even post-1.0). We would like to reduce the list of limitations over time.
The following list enumerates areas where Rustfmt does not work or where the
stability guarantees do not apply (we don't make a distinction between the two
## Installation
-```
-rustup component add rustfmt-preview
+```sh
+rustup component add rustfmt
```
## Installing from source
To install from source (nightly required), first checkout to the tag or branch you want to install, then issue
-```
+```sh
cargo install --path .
```
read data from stdin. Alternatively, you can use `cargo fmt` to format all
binary and library targets of your crate.
-You can run `rustfmt --help` for information about argument.
+You can run `rustfmt --help` for information about available arguments.
+The easiest way to run rustfmt against a project is with `cargo fmt`. `cargo fmt` works on both
+single-crate projects and [cargo workspaces](https://doc.rust-lang.org/book/ch14-03-cargo-workspaces.html).
+Please see `cargo fmt --help` for usage information.
+
+You can specify the path to your own `rustfmt` binary for cargo to use by setting the`RUSTFMT`
+environment variable. This was added in v1.4.22, so you must have this version or newer to leverage this feature (`cargo fmt --version`)
+
+### Running `rustfmt` directly
+
+To format individual files or arbitrary codes from stdin, the `rustfmt` binary should be used. Some
+examples follow:
+
+- `rustfmt lib.rs main.rs` will format "lib.rs" and "main.rs" in place
+- `rustfmt` will read a code from stdin and write formatting to stdout
+ - `echo "fn main() {}" | rustfmt` would emit "fn main() {}".
+
+For more information, including arguments and emit options, see `rustfmt --help`.
+
+### Verifying code is formatted
When running with `--check`, Rustfmt will exit with `0` if Rustfmt would not
make any formatting changes to the input, and `1` if Rustfmt would make changes.
It will also print any found differences. (Older versions of Rustfmt don't
support `--check`, use `--write-mode diff`).
-A minimal Travis setup could look like this (requires Rust 1.24.0 or greater):
+A minimal Travis setup could look like this (requires Rust 1.31.0 or greater):
```yaml
language: rust
before_script:
-- rustup component add rustfmt-preview
+- rustup component add rustfmt
script:
-- cargo fmt --all -- --check
- cargo build
- cargo test
+- cargo fmt --all -- --check
```
See [this blog post](https://medium.com/@ag_dubs/enforcing-style-in-ci-for-rust-projects-18f6b09ec69d)
`rustfmt.toml` or `.rustfmt.toml`, place it in the project or any other parent
directory and it will apply the options in that file. See `rustfmt
--help=config` for the options which are available, or if you prefer to see
-visual style previews, [Configurations.md](Configurations.md).
+visual style previews, [GitHub page](https://rust-lang.github.io/rustfmt/).
By default, Rustfmt uses a style which conforms to the [Rust style guide][style
guide] that has been formalized through the [style RFC
Configuration options are either stable or unstable. Stable options can always
be used, while unstable ones are only available on a nightly toolchain, and opt-in.
-See [Configurations.md](Configurations.md) for details.
+See [GitHub page](https://rust-lang.github.io/rustfmt/) for details.
+
+### Rust's Editions
+Rustfmt is able to pick up the edition used by reading the `Cargo.toml` file if
+executed through the Cargo's formatting tool `cargo fmt`. Otherwise, the edition
+needs to be specified in `rustfmt.toml`, e.g., with `edition = "2018"`.
## Tips
-* For things you do not want rustfmt to mangle, use one of
+* For things you do not want rustfmt to mangle, use `#[rustfmt::skip]`
+* To prevent rustfmt from formatting a macro or an attribute,
+ use `#[rustfmt::skip::macros(target_macro_name)]` or
+ `#[rustfmt::skip::attributes(target_attribute_name)]`
+
+ Example:
```rust
- #[rustfmt::skip] // requires nightly Rust and #![feature(tool_attributes)] in crate root
- #[cfg_attr(rustfmt, rustfmt_skip)] // works in stable
+ #![rustfmt::skip::attributes(custom_attribute)]
+
+ #[custom_attribute(formatting , here , should , be , Skipped)]
+ #[rustfmt::skip::macros(html)]
+ fn main() {
+ let macro_result1 = html! { <div>
+ Hello</div>
+ }.to_string();
```
* When you run rustfmt, place a file named `rustfmt.toml` or `.rustfmt.toml` in
target file directory or its parents to override the default settings of
Example:
- ```
+ ```sh
cargo fmt -- --emit files
```
| stdout | writes output to stdout | No |
| coverage | displays how much of the input file was processed | Yes |
| checkstyle | emits in a checkstyle format | Yes |
+ | json | emits diffs in a json format | Yes |
## License
See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT) for details.
[rust]: https://github.com/rust-lang/rust
-[fmt rfcs]: https://github.com/rust-lang-nursery/fmt-rfcs
-[style guide]: https://github.com/rust-lang-nursery/fmt-rfcs/blob/master/guide/guide.md
+[fmt rfcs]: https://github.com/rust-dev-tools/fmt-rfcs
+[style guide]: https://github.com/rust-dev-tools/fmt-rfcs/blob/master/guide/guide.md
projects / rust.git / blobdiff