Auto merge of #5943 - dwijnand:fix-allow-staged, r=alexcrichton

Add `--allow-staged` to `cargo fix`

Fixes #5737

This is @jljusten's branch, adapted to the testsuite changes in master.
Submitted as an alternative to #5910 to expedite #5737 resolution in time for Edition RC 1.

src/bin/cargo/commands/fix.rs

@@ -66,6 +66,11 @@ pub fn cli() -> App {
                 .long("allow-dirty")
                 .help("Fix code even if the working directory is dirty"),
         )
+        .arg(
+            Arg::with_name("allow-staged")
+                .long("allow-staged")
+                .help("Fix code even if the working directory has staged changes"),
+        )
         .after_help(
             "\
 This Cargo subcommmand will automatically take rustc's suggestions from
@@ -135,6 +140,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches) -> CliResult {
         compile_opts: opts,
         allow_dirty: args.is_present("allow-dirty"),
         allow_no_vcs: args.is_present("allow-no-vcs"),
+        allow_staged: args.is_present("allow-staged"),
         broken_code: args.is_present("broken-code"),
     })?;
     Ok(())

src/cargo/ops/fix.rs

@@ -33,6 +33,7 @@ pub struct FixOptions<'a> {
     pub compile_opts: CompileOptions<'a>,
     pub allow_dirty: bool,
     pub allow_no_vcs: bool,
+    pub allow_staged: bool,
     pub broken_code: bool,
 }
 
@@ -87,39 +88,57 @@ fn check_version_control(opts: &FixOptions) -> CargoResult<()> {
                error pass `--allow-no-vcs`")
     }
 
-    if opts.allow_dirty {
+    if opts.allow_dirty && opts.allow_staged {
         return Ok(())
     }
 
     let mut dirty_files = Vec::new();
+    let mut staged_files = Vec::new();
     if let Ok(repo) = git2::Repository::discover(config.cwd()) {
-        let mut opts = git2::StatusOptions::new();
-        opts.include_ignored(false);
-        for status in repo.statuses(Some(&mut opts))?.iter() {
-            if status.status() != git2::Status::CURRENT {
-                if let Some(path) = status.path() {
-                    dirty_files.push(path.to_string());
-                }
+        let mut repo_opts = git2::StatusOptions::new();
+        repo_opts.include_ignored(false);
+        for status in repo.statuses(Some(&mut repo_opts))?.iter() {
+            if let Some(path) = status.path() {
+                match status.status() {
+                    git2::Status::CURRENT => (),
+                    git2::Status::INDEX_NEW |
+                    git2::Status::INDEX_MODIFIED |
+                    git2::Status::INDEX_DELETED |
+                    git2::Status::INDEX_RENAMED |
+                    git2::Status::INDEX_TYPECHANGE =>
+                        if !opts.allow_staged {
+                            staged_files.push(path.to_string())
+                        },
+                    _ =>
+                        if !opts.allow_dirty {
+                            dirty_files.push(path.to_string())
+                        },
+                };
             }
 
         }
     }
 
-    if dirty_files.is_empty() {
+    if dirty_files.is_empty() && staged_files.is_empty() {
         return Ok(())
     }
 
     let mut files_list = String::new();
     for file in dirty_files {
         files_list.push_str("  * ");
         files_list.push_str(&file);
-        files_list.push_str("\n");
+        files_list.push_str(" (dirty)\n");
+    }
+    for file in staged_files {
+        files_list.push_str("  * ");
+        files_list.push_str(&file);
+        files_list.push_str(" (staged)\n");
     }
 
-    bail!("the working directory of this project is detected as dirty, and \
+    bail!("the working directory of this project has uncommitted changes, and \
            `cargo fix` can potentially perform destructive changes; if you'd \
-           like to suppress this error pass `--allow-dirty`, or commit the \
-           changes to these files:\n\
+           like to suppress this error pass `--allow-dirty`, `--allow-staged`, \
+           or commit the changes to these files:\n\
            \n\
            {}\n\
           ", files_list);

tests/testsuite/fix.rs

@@ -6,6 +6,8 @@ use support::git;
 use support::is_nightly;
 use support::{basic_manifest, project};
 
+use std::io::Write;
+
 #[test]
 fn do_not_fix_broken_builds() {
     let p = project()
@@ -725,19 +727,53 @@ fn warns_about_dirty_working_directory() {
         .with_status(101)
         .with_stderr(
             "\
-error: the working directory of this project is detected as dirty, and `cargo \
-fix` can potentially perform destructive changes; if you'd like to \
-suppress this error pass `--allow-dirty`, or commit the changes to \
-these files:
+error: the working directory of this project has uncommitted changes, \
+and `cargo fix` can potentially perform destructive changes; if you'd \
+like to suppress this error pass `--allow-dirty`, `--allow-staged`, or \
+commit the changes to these files:
 
-  * src/lib.rs
+  * src/lib.rs (dirty)
 
 
 ",
         ).run();
     p.cargo("fix --allow-dirty").run();
 }
 
+#[test]
+fn warns_about_staged_working_directory() {
+    let p = project().file("src/lib.rs", "pub fn foo() {}").build();
+
+    let repo = git2::Repository::init(&p.root()).unwrap();
+    let mut cfg = t!(repo.config());
+    t!(cfg.set_str("user.email", "foo@bar.com"));
+    t!(cfg.set_str("user.name", "Foo Bar"));
+    drop(cfg);
+    git::add(&repo);
+    git::commit(&repo);
+    File::create(&p.root().join("src/lib.rs"))
+        .unwrap()
+        .write_all("pub fn bar() {}".to_string().as_bytes())
+        .unwrap();
+    git::add(&repo);
+
+    p.cargo("fix")
+        .with_status(101)
+        .with_stderr(
+            "\
+error: the working directory of this project has uncommitted changes, \
+and `cargo fix` can potentially perform destructive changes; if you'd \
+like to suppress this error pass `--allow-dirty`, `--allow-staged`, or \
+commit the changes to these files:
+
+  * src/lib.rs (staged)
+
+
+",
+        ).run();
+    p.cargo("fix --allow-staged").run();
+}
+
 #[test]
 fn does_not_warn_about_clean_working_directory() {
     let p = project().file("src/lib.rs", "pub fn foo() {}").build();