Add git-fmt tool

Cargo.toml

@@ -22,6 +22,9 @@ name = "cargo-fmt"
 [[bin]]
 name = "rustfmt-format-diff"
 
+[[bin]]
+name = "git-fmt"
+
 [features]
 default = ["cargo-fmt", "rustfmt-format-diff"]
 cargo-fmt = []

src/bin/git-fmt.rs

@@ -0,0 +1,193 @@
+extern crate env_logger;
+extern crate getopts;
+#[macro_use]
+extern crate log;
+extern crate rustfmt_nightly as rustfmt;
+
+use std::env;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+use std::str::FromStr;
+
+use getopts::{Matches, Options};
+
+use rustfmt::{run, Input};
+use rustfmt::config;
+
+
+fn prune_files<'a>(files: Vec<&'a str>) -> Vec<&'a str> {
+    let prefixes: Vec<_> = files
+        .iter()
+        .filter(|f| f.ends_with("mod.rs") || f.ends_with("lib.rs"))
+        .map(|f| &f[..f.len() - 6])
+        .collect();
+
+    let mut pruned_prefixes = vec![];
+    for p1 in prefixes.into_iter() {
+        let mut include = true;
+        if !p1.starts_with("src/bin/") {
+            for p2 in pruned_prefixes.iter() {
+                if p1.starts_with(p2) {
+                    include = false;
+                    break;
+                }
+            }
+        }
+        if include {
+            pruned_prefixes.push(p1);
+        }
+    }
+    debug!("prefixes: {:?}", pruned_prefixes);
+
+    files
+        .into_iter()
+        .filter(|f| {
+            let mut include = true;
+            if f.ends_with("mod.rs") || f.ends_with("lib.rs") || f.starts_with("src/bin/") {
+                return true;
+            }
+            for pp in pruned_prefixes.iter() {
+                if f.starts_with(pp) {
+                    include = false;
+                    break;
+                }
+            }
+            include
+        })
+        .collect()
+}
+
+fn git_diff(commits: String) -> String {
+    let mut cmd = Command::new("git");
+    cmd.arg("diff");
+    if commits != "0" {
+        cmd.arg(format!("HEAD~{}", commits));
+    }
+    let output = cmd.output().expect("Couldn't execute `git diff`");
+    String::from_utf8_lossy(&output.stdout).into_owned()
+}
+
+fn get_files(input: &str) -> Vec<&str> {
+    input
+        .lines()
+        .filter(|line| line.starts_with("+++ b/") && line.ends_with(".rs"))
+        .map(|line| &line[6..])
+        .collect()
+}
+
+fn fmt_files(files: &[&str]) -> i32 {
+    let (config, _) = config::Config::from_resolved_toml_path(Path::new("."))
+        .unwrap_or_else(|_| (config::Config::default(), None));
+
+    let mut exit_code = 0;
+    for file in files {
+        let summary = run(Input::File(PathBuf::from(file)), &config);
+        if !summary.has_no_errors() {
+            exit_code = 1;
+        }
+    }
+    exit_code
+}
+
+fn uncommitted_files() -> Vec<String> {
+    let mut cmd = Command::new("git");
+    cmd.arg("ls-files");
+    cmd.arg("--others");
+    cmd.arg("--modified");
+    cmd.arg("--exclude-standard");
+    let output = cmd.output().expect("Couldn't execute Git");
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    stdout.lines().map(|s| s.to_owned()).collect()
+}
+
+fn check_uncommitted() {
+    let uncommitted = uncommitted_files();
+    debug!("uncommitted files: {:?}", uncommitted);
+    if !uncommitted.is_empty() {
+        println!("Found untracked changes:");
+        for f in uncommitted.iter() {
+            println!("  {}", f);
+        }
+        println!("Commit your work, or run with `-u`.");
+        println!("Exiting.");
+        std::process::exit(1);
+    }
+}
+
+fn make_opts() -> Options {
+    let mut opts = Options::new();
+    opts.optflag("h", "help", "show this message");
+    opts.optflag("c", "check", "check only, don't format (unimplemented)");
+    opts.optflag("u", "uncommitted", "format uncommitted files");
+    opts
+}
+
+struct Config {
+    commits: String,
+    uncommitted: bool,
+    check: bool,
+}
+
+impl Config {
+    fn from_args(matches: &Matches, opts: &Options) -> Config {
+        // `--help` display help message and quit
+        if matches.opt_present("h") {
+            let message = format!(
+                "\nusage: {} <commits> [options]\n\n\
+                 commits: number of commits to format, default: 1",
+                env::args_os().next().unwrap().to_string_lossy()
+            );
+            println!("{}", opts.usage(&message));
+            std::process::exit(0);
+        }
+
+        let mut config = Config {
+            commits: "1".to_owned(),
+            uncommitted: false,
+            check: false,
+        };
+
+        if matches.opt_present("c") {
+            config.check = true;
+            unimplemented!();
+        }
+
+        if matches.opt_present("u") {
+            config.uncommitted = true;
+        }
+
+        if matches.free.len() > 1 {
+            panic!("unknown arguments, use `-h` for usage");
+        }
+        if matches.free.len() == 1 {
+            let commits = matches.free[0].trim();
+            if let Err(_) = u32::from_str(&commits) {
+                panic!("Couldn't parse number of commits");
+            }
+            config.commits = commits.to_owned();
+        }
+
+        config
+    }
+}
+
+fn main() {
+    let _ = env_logger::init();
+
+    let opts = make_opts();
+    let matches = opts.parse(env::args().skip(1))
+        .expect("Couldn't parse command line");
+    let config = Config::from_args(&matches, &opts);
+
+    if !config.uncommitted {
+        check_uncommitted();
+    }
+
+    let stdout = git_diff(config.commits);
+    let files = get_files(&stdout);
+    debug!("files: {:?}", files);
+    let files = prune_files(files);
+    debug!("pruned files: {:?}", files);
+    let exit_code = fmt_files(&files);
+    std::process::exit(exit_code);
+}