Fix error conversion and remove dead code

Cargo.toml

@@ -14,5 +14,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+anyhow = { version = "1.0.75", features = ["backtrace"] }
 cargo-util = "0.2.6"
 git2 = "0.18.1"
+thiserror = "1.0.50"

src/check.rs

@@ -1,5 +1,4 @@
 use super::VCSResult;
-use cargo_util::paths;
 use cargo_util::ProcessBuilder;
 use std::path::Path;
 
@@ -27,13 +26,13 @@ pub fn check_version_control<P: AsRef<Path>>(path: P, opts: &CheckOptions) -> VC
     if opts.allow_no_vcs {
         return Ok(());
     }
-    // if !existing_vcs_repo(path, path) {
-    //     bail!(
-    //         "no VCS found for this package and `cargo fix` can potentially \
-    //          perform destructive changes; if you'd like to suppress this \
-    //          error pass `--allow-no-vcs`"
-    //     )
-    // }
+    if !existing_vcs_repo(path.as_ref(), path.as_ref()) {
+        // bail!(
+        //     "no VCS found for this package and `cargo fix` can potentially \
+        //      perform destructive changes; if you'd like to suppress this \
+        //      error pass `--allow-no-vcs`"
+        // )
+    }
 
     // if opts.allow_dirty && opts.allow_staged {
     //     return Ok(());
@@ -121,29 +120,14 @@ pub fn existing_vcs_repo(path: &Path, cwd: &Path) -> bool {
 
 pub struct HgRepo;
 pub struct GitRepo;
-pub struct PijulRepo;
-pub struct FossilRepo;
 
 impl GitRepo {
-    pub fn init(path: &Path, _: &Path) -> VCSResult<GitRepo> {
-        git2::Repository::init(path)?;
-        Ok(GitRepo)
-    }
     pub fn discover(path: &Path, _: &Path) -> Result<git2::Repository, git2::Error> {
         git2::Repository::discover(path)
     }
 }
 
 impl HgRepo {
-    pub fn init(path: &Path, cwd: &Path) -> VCSResult<HgRepo> {
-        ProcessBuilder::new("hg")
-            .cwd(cwd)
-            .arg("init")
-            .arg("--")
-            .arg(path)
-            .exec()?;
-        Ok(HgRepo)
-    }
     pub fn discover(path: &Path, cwd: &Path) -> VCSResult<HgRepo> {
         ProcessBuilder::new("hg")
             .cwd(cwd)
@@ -154,45 +138,3 @@ impl HgRepo {
         Ok(HgRepo)
     }
 }
-
-impl PijulRepo {
-    pub fn init(path: &Path, cwd: &Path) -> VCSResult<PijulRepo> {
-        ProcessBuilder::new("pijul")
-            .cwd(cwd)
-            .arg("init")
-            .arg("--")
-            .arg(path)
-            .exec()?;
-        Ok(PijulRepo)
-    }
-}
-
-impl FossilRepo {
-    pub fn init(path: &Path, cwd: &Path) -> VCSResult<FossilRepo> {
-        // fossil doesn't create the directory so we'll do that first
-        paths::create_dir_all(path)?;
-
-        // set up the paths we'll use
-        let db_fname = ".fossil";
-        let mut db_path = path.to_owned();
-        db_path.push(db_fname);
-
-        // then create the fossil DB in that location
-        ProcessBuilder::new("fossil")
-            .cwd(cwd)
-            .arg("init")
-            .arg("--")
-            .arg(&db_path)
-            .exec()?;
-
-        // open it in that new directory
-        ProcessBuilder::new("fossil")
-            .cwd(&path)
-            .arg("open")
-            .arg("--")
-            .arg(db_fname)
-            .exec()?;
-
-        Ok(FossilRepo)
-    }
-}

src/error.rs

@@ -1,51 +1,43 @@
-use std::{error::Error, fmt::Display};
+use thiserror::Error;
 
 /// Enumerates the possible error values that can be generated by this crate
-#[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug)]
+#[derive(Error, Debug)]
 #[non_exhaustive]
 pub enum VSCError {
     /// Unable to detect a version control system
+    #[error("no vcs")]
     NoVCS,
     /// Found a type of file that was not allowed. Includes listing of disallowed files found
+    #[error("{}", format_disallowed_files(dirty_files, staged_files))]
     NotAllowedFilesFound {
         /// Dirty files found (note this will be empty if dirty files are allowed)
         dirty_files: Vec<String>,
         /// Staged files found (note this will be empty if staged files are allowed)
         staged_files: Vec<String>,
     },
+    /// Errors produced outside of the ones from this library
+    #[error(transparent)]
+    Other(#[from] anyhow::Error), // source and Display delegate to anyhow::Error
 }
 
-impl Display for VSCError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            VSCError::NoVCS => write!(f, "no VCS found but this not allowed"),
-            VSCError::NotAllowedFilesFound {
-                dirty_files,
-                staged_files,
-            } => {
-                let mut files_list = String::new();
-                for file in dirty_files {
-                    files_list.push_str("  * ");
-                    files_list.push_str(file);
-                    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");
-                }
-
-                write!(
-                    f,
-                    "disallowed files found:\n\
-                     \n\
-                     {}\n\
-                     ",
-                    files_list
-                )
-            }
-        }
+fn format_disallowed_files(dirty_files: &[String], staged_files: &[String]) -> String {
+    let mut files_list = String::new();
+    for file in dirty_files {
+        files_list.push_str("  * ");
+        files_list.push_str(file);
+        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");
     }
-}
 
-impl Error for VSCError {}
+    format!(
+        "disallowed files found:\n\
+         \n\
+         {}\n\
+         ",
+        files_list
+    )
+}

src/lib.rs

@@ -10,6 +10,7 @@
 mod check;
 mod error;
 
-pub type VCSResult<T> = Result<T, error::VSCError>;
+/// Type alias for Result<T, [`VSCError`]>
+pub type VCSResult<T> = Result<T, VSCError>;
 pub use check::{check_version_control, CheckOptions};
 pub use error::VSCError;