Use git cli instead of git2

This significantly reduces the amount of dependencies and most users of
cargo-minify likely have git installed anyway.

Cargo.toml

@@ -15,7 +15,6 @@ name = "useless"
 [dependencies]
 cargo_metadata = "0.17"
 diff = "0.1.13"
-git2 = "0.17"
 glob-match = "0.2.1"
 gumdrop = "0.8"
 proc-macro2 = { version = "1.0.66", features = ["span-locations"] }

src/vcs/mod.rs

@@ -1,3 +1,4 @@
+use std::io;
 use std::path::Path;
 
 mod check_vcs;
@@ -13,39 +14,47 @@ pub enum Status {
         staged: Vec<String>,
     },
     NoVCS,
-    Error(git2::Error),
+    Error(io::Error),
 }
 
-// Portions of the below code are inspired by/taken from Cargo, https://github.com/rust-lang/cargo/
-// Copyright (c) 2016-2021 The Cargo Developers
-
 fn check_version_control(path: &Path) -> Status {
     if !check_vcs::existing_vcs_repo(path) {
         return Status::NoVCS;
     }
 
-    let mut dirty = Vec::new();
-    let mut staged = Vec::new();
-    if let Ok(repo) = git2::Repository::discover(path) {
-        let mut repo_opts = git2::StatusOptions::new();
-        repo_opts.include_ignored(false);
-        repo_opts.include_untracked(true);
-        let statuses = match repo.statuses(Some(&mut repo_opts)) {
-            Ok(value) => value,
-            Err(error) => return Status::Error(error),
-        };
-        for status in statuses.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 => staged.push(path.to_string()),
-                    _ => dirty.push(path.to_string()),
-                };
-            }
+    let output = match std::process::Command::new("git")
+        .current_dir(path)
+        .arg("status")
+        .arg("--porcelain=v1")
+        .output()
+    {
+        Ok(output) if output.status.success() => output,
+        Ok(output) => {
+            return Status::Error(io::Error::new(
+                io::ErrorKind::Other,
+                format!(
+                    "git status failed with exit code {}:\nstdout:\n{}\n\nstderr:\n{}",
+                    output.status,
+                    String::from_utf8_lossy(&output.stdout),
+                    String::from_utf8_lossy(&output.stderr),
+                ),
+            ))
+        }
+        Err(err) => return Status::Error(err),
+    };
+    let stdout = output.stdout;
+    let mut dirty = vec![];
+    let mut staged = vec![];
+    for line in String::from_utf8_lossy(&stdout).lines() {
+        if line.starts_with("M ") || line.starts_with("A ") {
+            staged.push(line[2..].to_owned());
+        } else if line.starts_with(" M") || line.starts_with("??") {
+            dirty.push(line[2..].to_owned());
+        } else {
+            return Status::Error(io::Error::new(
+                io::ErrorKind::Other,
+                format!("git status returned invalid data: {line:?}"),
+            ));
         }
     }