refactor: have per-module error enums

This means that a function that parses step bindings can't return an
error that the document is missing a title. Such an error return would
be nonsensical, and we use the Rust type system to prevent it, at a
small cost of being a bit verbose.

Additional benefit is that the library portion of Obnam doesn't return
anyhow::Result values anymore.

1 files changed, 14 insertions, 3 deletions

diff --git a/src/fsiter.rs b/src/fsiter.rs
index a40ad34..36693a6 100644
--- a/src/fsiter.rs
+++ b/src/fsiter.rs
@@ -1,4 +1,4 @@
-use crate::fsentry::FilesystemEntry;
+use crate::fsentry::{FilesystemEntry, FsEntryError};
 use log::info;
 use std::path::Path;
 use walkdir::{IntoIter, WalkDir};
@@ -8,6 +8,17 @@ pub struct FsIterator {
     iter: IntoIter,
 }
 
+#[derive(Debug, thiserror::Error)]
+pub enum FsIterError {
+    #[error(transparent)]
+    WalkError(#[from] walkdir::Error),
+
+    #[error(transparent)]
+    FsEntryError(#[from] FsEntryError),
+}
+
+pub type FsIterResult<T> = Result<T, FsIterError>;
+
 impl FsIterator {
     pub fn new(root: &Path) -> Self {
         Self {
@@ -17,7 +28,7 @@ impl FsIterator {
 }
 
 impl Iterator for FsIterator {
-    type Item = Result<FilesystemEntry, anyhow::Error>;
+    type Item = FsIterResult<FilesystemEntry>;
     fn next(&mut self) -> Option<Self::Item> {
         match self.iter.next() {
             None => None,
@@ -30,7 +41,7 @@ impl Iterator for FsIterator {
     }
 }
 
-fn new_entry(e: &walkdir::DirEntry) -> anyhow::Result<FilesystemEntry> {
+fn new_entry(e: &walkdir::DirEntry) -> FsIterResult<FilesystemEntry> {
     let meta = e.metadata()?;
     let entry = FilesystemEntry::from_metadata(e.path(), &meta)?;
     Ok(entry)