rust-format

A Rust source code formatting crate with a unified interface for string, file, and TokenStream input. It currently supports rustfmt and prettyplease.

It optionally supports post-processing replacement of special blank/comment markers for inserting blank lines and comments in TokenStream generated source code respectively (as used by quote-doctest for inserting blanks/comments in generated doctests). It additionally supports converting doc blocks (#[doc =""]) into doc comments (///).

NOTE: This is primarily to support rustfmt as prettyplease automatically converts doc blocks into doc comments (but for rustfmt it requires nightly and a configuration option).

Usage

[dependencies]
rust-format = "0.3"

Optional Features

• post_process - enables support for post-process conversion of special "marker macros" into blank lines/comments. It additionally supports converting doc blocks (#[doc]) into doc comments (///)
• pretty_please - enables prettyplease formatting support
• token_stream - enables formatting from TokenStream input

Examples

Simple example using default options of RustFmt:

use rust_format::{Formatter, RustFmt};

fn main() {
    let source = r#"fn main() { println!("Hello World!"); }"#;

    let actual = RustFmt::default().format_str(source).unwrap();
    let expected = r#"fn main() {
    println!("Hello World!");
}
"#;

    assert_eq!(expected, actual);
}

Using a custom configuration:

use rust_format::{Config, Edition, Formatter, RustFmt};

fn main() {
    let source = r#"use std::marker; use std::io; mod test; mod impls;"#;
  
    let mut config = Config::new_str()
        .edition(Edition::Rust2018)
        .option("reorder_imports", "false")
        .option("reorder_modules", "false");
    let rustfmt = RustFmt::from_config(config);
  
    let actual = rustfmt.format_str(source).unwrap();
    let expected = r#"use std::marker;
use std::io;
mod test;
mod impls;
"#;
  
    assert_eq!(expected, actual);
}

RustFmt with post-processing:

use quote::quote;
use rust_format::{Config, Formatter, PostProcess, RustFmt};

fn main() {
    let source = quote! {
        #[doc = " This is main"] 
        fn main() { 
            _blank_!();
            _comment_!("\nThis prints hello world\n\n"); 
            println!("Hello World!"); 
        }
    };

    let mut config = Config::new_str()
        .post_proc(PostProcess::ReplaceMarkersAndDocBlocks);
    let actual = RustFmt::from_config(config).format_tokens(source).unwrap();
    let expected = r#"/// This is main
fn main() {

    //
    // This prints hello world
    //
    println!("Hello World!");
}
"#;

    assert_eq!(expected, actual);
}

License

This project is licensed optionally under either:

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)