change!: use separate error types for the eol and ident filters

Prepare for hashing becoming fallible.

Author: emilazy

gix-filter/src/eol/convert_to_worktree.rs

@@ -5,14 +5,22 @@ use crate::{
     eol::{AttributesDigest, Configuration, Mode, Stats},
 };
 
+/// The error produced by [`convert_to_worktree()`].
+#[derive(Debug, thiserror::Error)]
+#[allow(missing_docs)]
+pub enum Error {
+    #[error("Could not allocate buffer")]
+    OutOfMemory(#[from] std::collections::TryReserveError),
+}
+
 /// Convert all `\n` in `src` to `crlf` if `digest` and `config` indicate it, returning `true` if `buf` holds the result, or `false`
 /// if no change was made after all.
 pub fn convert_to_worktree(
     src: &[u8],
     digest: AttributesDigest,
     buf: &mut Vec<u8>,
     config: Configuration,
-) -> Result<bool, std::collections::TryReserveError> {
+) -> Result<bool, Error> {
     if src.is_empty() || digest.to_eol(config) != Some(Mode::CrLf) {
         return Ok(false);
     }

gix-filter/src/eol/mod.rs

@@ -2,7 +2,8 @@
 pub mod convert_to_git;
 pub use convert_to_git::function::convert_to_git;
 
-mod convert_to_worktree;
+///
+pub mod convert_to_worktree;
 pub use convert_to_worktree::convert_to_worktree;
 
 mod utils;

gix-filter/src/ident.rs

@@ -40,6 +40,17 @@ pub fn undo(src: &[u8], buf: &mut Vec<u8>) -> Result<bool, std::collections::Try
     Ok(initialized)
 }
 
+///
+pub mod apply {
+    /// The error produced by [`super::apply()`].
+    #[derive(Debug, thiserror::Error)]
+    #[allow(missing_docs)]
+    pub enum Error {
+        #[error("Could not allocate buffer")]
+        OutOfMemory(#[from] std::collections::TryReserveError),
+    }
+}
+
 /// Substitute all occurrences of `$Id$` with `$Id: <hexsha-of-input>$` if present in `src` and write all changes to `buf`,
 /// with `object_hash` being used accordingly. Return `true` if `buf` was written to or `false` if no change was made
 /// (as there was nothing to do).
@@ -48,11 +59,7 @@ pub fn undo(src: &[u8], buf: &mut Vec<u8>) -> Result<bool, std::collections::Try
 ///
 /// `Git` also tries to cleanup 'stray' substituted `$Id: <hex>$`, but we don't do that, sticking exactly to what ought to be done.
 /// The respective code is up to 16 years old and one might assume that `git` by now handles checking and checkout filters correctly.
-pub fn apply(
-    src: &[u8],
-    object_hash: gix_hash::Kind,
-    buf: &mut Vec<u8>,
-) -> Result<bool, std::collections::TryReserveError> {
+pub fn apply(src: &[u8], object_hash: gix_hash::Kind, buf: &mut Vec<u8>) -> Result<bool, apply::Error> {
     const HASH_LEN: usize = ": ".len() + gix_hash::Kind::longest().len_in_hex();
     let mut id = None;
     let mut ofs = 0;

gix-filter/src/pipeline/convert.rs

@@ -49,14 +49,16 @@ pub mod to_worktree {
     #[derive(Debug, thiserror::Error)]
     #[allow(missing_docs)]
     pub enum Error {
+        #[error(transparent)]
+        Ident(#[from] crate::ident::apply::Error),
+        #[error(transparent)]
+        Eol(#[from] crate::eol::convert_to_worktree::Error),
         #[error(transparent)]
         Worktree(#[from] crate::worktree::encode_to_worktree::Error),
         #[error(transparent)]
         Driver(#[from] crate::driver::apply::Error),
         #[error(transparent)]
         Configuration(#[from] super::configuration::Error),
-        #[error("Could not allocate buffer")]
-        OutOfMemory(#[from] std::collections::TryReserveError),
     }
 }