-# rustfmt [](https://travis-ci.org/rust-lang-nursery/rustfmt) [](https://ci.appveyor.com/project/nrc/rustfmt) [](https://crates.io/crates/rustfmt-nightly)
+# 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)
A tool for formatting Rust code according to style guidelines.
If you'd like to help out (and you should, it's a fun project!), see
-[Contributing.md](Contributing.md).
+[Contributing.md](Contributing.md) and our [Code of
+Conduct](CODE_OF_CONDUCT.md).
We are changing the default style used by rustfmt. There is an ongoing [RFC
process][fmt rfcs]. The last version using the old style was 0.8.6. From 0.9
to be a bit out of date). Version 0.1 of rustfmt-nightly is forked from version
0.9 of the syntex branch.
+You can use rustfmt in Travis CI builds. We provide a minimal Travis CI
+configuration (see [here](#checking-style-on-a-ci-server)) and verify its status
+using another repository. The status of that repository's build is reported by
+the "travis example" badge above.
+
## Quick start
-You must be using the latest nightly compiler toolchain.
+You can use `rustfmt` on Rust 1.24 and above.
To install:
```
-cargo install rustfmt-nightly
+rustup component add rustfmt-preview
```
to run on a cargo project in the current working directory:
cargo fmt
```
-## Installation
-```
-cargo install rustfmt-nightly
-```
+## Limitations
-or if you're using [Rustup](https://www.rustup.rs/)
+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.
-```
-rustup update
-rustup run nightly cargo install rustfmt-nightly
-```
+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
+because in the future Rustfmt might work on code where it currently does not):
-If you don't have a nightly toolchain, you can add it using rustup:
+* a program where any part of the program does not parse (parsing is an early
+ stage of compilation and in Rust includes macro expansion).
+* Macro declarations and uses (current status: some macro declarations and uses
+ are formatted).
+* Comments, including any AST node with a comment 'inside' (Rustfmt does not
+ currently attempt to format comments, it does format code with comments inside, but that formatting may change in the future).
+* Rust code in code blocks in comments.
+* Any fragment of a program (i.e., stability guarantees only apply to whole
+ programs, even where fragments of a program can be formatted today).
+* Code containing non-ascii unicode characters (we believe Rustfmt mostly works
+ here, but do not have the test coverage or experience to be 100% sure).
+* Bugs in Rustfmt (like any software, Rustfmt has bugs, we do not consider bug
+ fixes to break our stability guarantees).
-```
-rustup install nightly
-```
-You can make the nightly toolchain the default by running:
+## Installation
```
-rustup default nightly
+rustup component add rustfmt-preview
```
-If you choose not to do that you'll have to run rustfmt using `rustup run ...`
-or by adding `+nightly` to the cargo invocation.
-
-Usually cargo-fmt, which enables usage of Cargo subcommand `cargo fmt`, is
-installed alongside rustfmt. To only install rustfmt run
-
-```
-cargo install --no-default-features rustfmt-nightly
-```
## Installing from source
To install from source, first checkout to the tag or branch you want to install, then issue
rustfmt to exit with an error code if the input is not formatted correctly.
It will also print any found differences.
-(These instructions use the nightly version of Rustfmt. If you want to use the
-Syntex version replace `install rustfmt-nightly` with `install rustfmt`).
-
-A minimal Travis setup could look like this:
+A minimal Travis setup could look like this (requires Rust 1.24.0 or greater):
```yaml
language: rust
-cache: cargo
before_script:
-- export PATH="$PATH:$HOME/.cargo/bin"
-- which rustfmt || cargo install rustfmt-nightly
+- rustup component add rustfmt-preview
script:
-- cargo fmt -- --write-mode=diff
+- cargo fmt --all -- --write-mode=diff
- cargo build
- cargo test
```
-Note that using `cache: cargo` is optional but highly recommended to speed up the installation.
-
## How to build and test
`cargo build` to build.
projects / rust.git / blobdiff