X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=README.md;h=c9153a6eade4d769c594eadfe12dccd12cb3b4fd;hb=cbd568083d87a90dfe5ab0e90f404454946c9f20;hp=fbb5fbbc17ad70cfbe72fcc014807631c5af62b2;hpb=724f75eaa5d5eb72baabab7bc3ec3b8ed0d52815;p=rust.git diff --git a/README.md b/README.md index fbb5fbbc17a..c9153a6eade 100644 --- a/README.md +++ b/README.md @@ -1,16 +1,24 @@ -# rustfmt [![Build Status](https://travis-ci.org/rust-lang-nursery/rustfmt.svg)](https://travis-ci.org/rust-lang-nursery/rustfmt) [![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt?svg=true)](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt) +# rustfmt [![Build Status](https://travis-ci.org/rust-lang-nursery/rustfmt.svg)](https://travis-ci.org/rust-lang-nursery/rustfmt) [![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt?svg=true)](https://ci.appveyor.com/project/nrc/rustfmt) [![crates.io](https://img.shields.io/crates/v/rustfmt-nightly.svg)](https://crates.io/crates/rustfmt-nightly) [![Travis Configuration Status](https://img.shields.io/travis/davidalber/rustfmt-travis.svg?label=travis%20example)](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). + +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 can run `rustfmt` with Rust 1.24 and above. + To install: ``` -cargo install rustfmt +rustup component add rustfmt-preview ``` to run on a cargo project in the current working directory: @@ -19,36 +27,68 @@ to run on a cargo project in the current working directory: cargo fmt ``` -## Installation - -> **Note:** this method currently requires you to be running cargo 0.6.0 or -> newer. - +For the latest and greatest `rustfmt` (nightly required): +``` +rustup component add rustfmt-preview --toolchain nightly ``` -cargo install rustfmt +To run: +``` +cargo +nightly fmt ``` -or if you're using [`rustup.rs`](https://www.rustup.rs/) +To format code that requires edition 2018, create a `rustfmt.toml` [configuration](#configuring-rustfmt) file containing: -``` -rustup run nightly cargo install rustfmt +```toml +edition = "2018" ``` -Usually cargo-fmt, which enables usage of Cargo subcommand `cargo fmt`, is -installed alongside rustfmt. To only install rustfmt run +## 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. + +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): + +* 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). + + +## Installation ``` -cargo install --no-default-features rustfmt +rustup component add rustfmt-preview ``` + ## Installing from source -To install from source, first checkout to the tag or branch you want to install, then issue +To install from source (nightly required), first checkout to the tag or branch you want to install, then issue + ``` -cargo install --path . +cargo install --path . ``` -This will install `rustfmt` in your `~/.cargo/bin`. Make sure to add `~/.cargo/bin` directory to + +This will install `rustfmt` in your `~/.cargo/bin`. Make sure to add `~/.cargo/bin` directory to your PATH variable. + ## Running You can run Rustfmt by just typing `rustfmt filename` if you used `cargo @@ -58,82 +98,47 @@ just need to run on the root file (usually mod.rs or lib.rs). Rustfmt can also read data from stdin. Alternatively, you can use `cargo fmt` to format all binary and library targets of your crate. -You'll probably want to specify the write mode. Currently, there are modes for -diff, replace, overwrite, display, coverage, and checkstyle. +You can run `rustfmt --help` for information about argument. -* `replace` Is the default and overwrites the original files after creating backups of the files. -* `overwrite` Overwrites the original files _without_ creating backups. -* `display` Will print the formatted files to stdout. -* `diff` Will print a diff between the original files and formatted files to stdout. - Will also exit with an error code if there are any differences. -* `checkstyle` Will output the lines that need to be corrected as a checkstyle XML file, - that can be used by tools like Jenkins. +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. +In other modes, Rustfmt will exit with `1` if there was some error during +formatting (for example a parsing or internal error) and `0` if formatting +completed without error (whether or not changes were made). -The write mode can be set by passing the `--write-mode` flag on -the command line. For example `rustfmt --write-mode=display src/filename.rs` - -`cargo fmt` uses `--write-mode=replace` by default. - -If you want to restrict reformatting to specific sets of lines, you can -use the `--file-lines` option. Its argument is a JSON array of objects -with `file` and `range` properties, where `file` is a file name, and -`range` is an array representing a range of lines like `[7,13]`. Ranges -are 1-based and inclusive of both end points. Specifying an empty array -will result in no files being formatted. For example, - -``` -rustfmt --file-lines '[ - {"file":"src/lib.rs","range":[7,13]}, - {"file":"src/lib.rs","range":[21,29]}, - {"file":"src/foo.rs","range":[10,11]}, - {"file":"src/foo.rs","range":[15,15]}]' -``` - -would format lines `7-13` and `21-29` of `src/lib.rs`, and lines `10-11`, -and `15` of `src/foo.rs`. No other files would be formatted, even if they -are included as out of line modules from `src/lib.rs`. - -If `rustfmt` successfully reformatted the code it will exit with `0` exit -status. Exit status `1` signals some unexpected error, like an unknown option or -a failure to read a file. Exit status `2` is returned if there are syntax errors -in the input files. `rustfmt` can't format syntatically invalid code. Finally, -exit status `3` is returned if there are some issues which can't be resolved -automatically. For example, if you have a very long comment line `rustfmt` -doesn't split it. Instead it prints a warning and exits with `3`. - -You can run `rustfmt --help` for more information. ## Running Rustfmt from your editor * [Vim](https://github.com/rust-lang/rust.vim#formatting-with-rustfmt) * [Emacs](https://github.com/rust-lang/rust-mode) -* [Sublime Text 3](https://packagecontrol.io/packages/BeautifyRust) +* [Sublime Text 3](https://packagecontrol.io/packages/RustFmt) * [Atom](atom.md) -* Visual Studio Code using [RustyCode](https://github.com/saviorisdead/RustyCode) or [vsc-rustfmt](https://github.com/Connorcpu/vsc-rustfmt) +* Visual Studio Code using [vscode-rust](https://github.com/editor-rs/vscode-rust), [vsc-rustfmt](https://github.com/Connorcpu/vsc-rustfmt) or [rls_vscode](https://github.com/jonathandturner/rls_vscode) through RLS. + ## Checking style on a CI server To keep your code base consistently formatted, it can be helpful to fail the CI build -when a pull request contains unformatted code. Using `--write-mode=diff` instructs +when a pull request contains unformatted code. Using `--check` instructs rustfmt to exit with an error code if the input is not formatted correctly. -It will also print any found differences. +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: +A minimal Travis setup could look like this (requires Rust 1.24.0 or greater): ```yaml language: rust -cache: cargo -before_script: (cargo install rustfmt || true) +before_script: +- rustup component add rustfmt-preview script: -- | - export PATH=$PATH:~/.cargo/bin && - cargo fmt -- --write-mode=diff && - cargo build && - cargo test +- cargo fmt --all -- --check +- cargo build +- cargo test ``` -Note that using `cache: cargo` is optional but highly recommended to speed up the installation. +See [this blog post](https://medium.com/@ag_dubs/enforcing-style-in-ci-for-rust-projects-18f6b09ec69d) +for more info. ## How to build and test @@ -150,19 +155,16 @@ notes above on running rustfmt. Rustfmt is designed to be very configurable. You can create a TOML file called `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 ---config-help` for the options which are available, or if you prefer to see -source code, [src/config.rs](src/config.rs). +--help=config` for the options which are available, or if you prefer to see +visual style previews, [Configurations.md](Configurations.md). -By default, Rustfmt uses a style which (mostly) conforms to the -[Rust style guidelines](https://github.com/rust-lang/rust/tree/master/src/doc/style). -There are many details which the style guidelines do not cover, and in these -cases we try to adhere to a style similar to that used in the -[Rust repo](https://github.com/rust-lang/rust). Once Rustfmt is more complete, and -able to re-format large repositories like Rust, we intend to go through the Rust -RFC process to nail down the default style in detail. +By default, Rustfmt uses a style which conforms to the [Rust style guide][style +guide] that has been formalized through the [style RFC +process][fmt rfcs]. -If there are styling choices you don't agree with, we are usually happy to add -options covering different styles. File an issue, or even better, submit a PR. +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. ## Tips @@ -170,17 +172,34 @@ options covering different styles. File an issue, or even better, submit a PR. * For things you do not want rustfmt to mangle, use one of ```rust - #[rustfmt_skip] // requires nightly and #![feature(custom_attribute)] in crate root + #[rustfmt::skip] // requires nightly Rust and #![feature(tool_attributes)] in crate root #[cfg_attr(rustfmt, rustfmt_skip)] // works in stable ``` * 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 - rustfmt. + rustfmt. You can generate a file containing the default configuration with + `rustfmt --print-config default rustfmt.toml` and customize as needed. * After successful compilation, a `rustfmt` executable can be found in the target directory. * If you're having issues compiling Rustfmt (or compile errors when trying to install), make sure you have the most recent version of Rust installed. +* You can change the way rustfmt emits the changes with the --emit flag: + + Example: + + ``` + cargo fmt -- --emit files + ``` + + Options: + + | Flag |Description| Nightly Only | + |:---:|:---:|:---:| + | files | overwrites output to files | No | + | stdout | writes output to stdout | No | + | coverage | displays how much of the input file was processed | Yes | + | checkstyle | emits in a checkstyle format | Yes | ## License @@ -188,3 +207,7 @@ Rustfmt is distributed under the terms of both the MIT license and the Apache License (Version 2.0). 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