Split fs watcher errors into their own enum

lib/src/error/runtime.rs

@@ -37,65 +37,16 @@ pub enum RuntimeError {
 		err: std::io::Error,
 	},
 
-	/// Error received when creating a filesystem watcher fails.
-	#[error("{kind:?} watcher failed to instantiate: {err}")]
-	#[diagnostic(
-		code(watchexec::runtime::fs_watcher_error),
-		help("perhaps retry with the poll watcher")
-	)]
-	FsWatcherCreate {
+	/// Events from the filesystem watcher event source.
+	#[error("{kind:?} fs watcher error")]
+	#[diagnostic(code(watchexec::runtime::fs_watcher))]
+	FsWatcher {
 		/// The kind of watcher that failed to instantiate.
 		kind: Watcher,
 
 		/// The underlying error.
 		#[source]
-		err: notify::Error,
-
-		/// A hint to the user about resolving the error.
-		#[source_code]
-		help: String,
-	},
-
-	/// Error received when reading a filesystem event fails.
-	#[error("{kind:?} watcher received an event that we could not read: {err}")]
-	#[diagnostic(code(watchexec::runtime::fs_watcher_event))]
-	FsWatcherEvent {
-		/// The kind of watcher that failed to read an event.
-		kind: Watcher,
-
-		/// The underlying error.
-		#[source]
-		err: notify::Error,
-	},
-
-	/// Error received when adding to the pathset for the filesystem watcher fails.
-	#[error("while adding {path:?} to the {kind:?} watcher: {err}")]
-	#[diagnostic(code(watchexec::runtime::fs_watcher_path_add))]
-	FsWatcherPathAdd {
-		/// The path that was attempted to be added.
-		path: PathBuf,
-
-		/// The kind of watcher that failed to add a path.
-		kind: Watcher,
-
-		/// The underlying error.
-		#[source]
-		err: notify::Error,
-	},
-
-	/// Error received when removing from the pathset for the filesystem watcher fails.
-	#[error("while removing {path:?} from the {kind:?} watcher: {err}")]
-	#[diagnostic(code(watchexec::runtime::fs_watcher_path_remove))]
-	FsWatcherPathRemove {
-		/// The path that was attempted to be removed.
-		path: PathBuf,
-
-		/// The kind of watcher that failed to remove a path.
-		kind: Watcher,
-
-		/// The underlying error.
-		#[source]
-		err: notify::Error,
+		err: super::FsWatcherError,
 	},
 
 	/// Opaque internal error from a command supervisor.

lib/src/error/specialised.rs

@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::{collections::HashMap, path::PathBuf};
 
 use ignore::gitignore::Gitignore;
 use miette::Diagnostic;
@@ -126,3 +126,54 @@ impl From<TaggedFiltererError> for RuntimeError {
 		}
 	}
 }
+
+/// Errors emitted by the filesystem watcher.
+#[derive(Debug, Diagnostic, Error)]
+#[non_exhaustive]
+#[diagnostic(url(docsrs))]
+pub enum FsWatcherError {
+	/// Error received when creating a filesystem watcher fails.
+	#[error("failed to instantiate")]
+	#[diagnostic(
+		code(watchexec::fs_watcher::create),
+		help("perhaps retry with the poll watcher")
+	)]
+	Create {
+		/// The underlying error.
+		#[source]
+		err: notify::Error,
+
+		/// A hint to the user about resolving the error.
+		#[source_code]
+		help: String,
+	},
+
+	/// Error received when reading a filesystem event fails.
+	#[error("received an event that we could not read")]
+	#[diagnostic(code(watchexec::fs_watcher::event))]
+	Event(#[source] notify::Error),
+
+	/// Error received when adding to the pathset for the filesystem watcher fails.
+	#[error("while adding {path:?}")]
+	#[diagnostic(code(watchexec::fs_watcher::path_add))]
+	PathAdd {
+		/// The path that was attempted to be added.
+		path: PathBuf,
+
+		/// The underlying error.
+		#[source]
+		err: notify::Error,
+	},
+
+	/// Error received when removing from the pathset for the filesystem watcher fails.
+	#[error("while removing {path:?}")]
+	#[diagnostic(code(watchexec::fs_watcher::path_remove))]
+	PathRemove {
+		/// The path that was attempted to be removed.
+		path: PathBuf,
+
+		/// The underlying error.
+		#[source]
+		err: notify::Error,
+	},
+}

lib/src/fs.rs

@@ -14,7 +14,7 @@ use tokio::sync::{mpsc, watch};
 use tracing::{debug, error, trace, warn};
 
 use crate::{
-	error::{CriticalError, RuntimeError},
+	error::{CriticalError, FsWatcherError, RuntimeError},
 	event::{Event, Source, Tag},
 };
 
@@ -51,8 +51,9 @@ impl Watcher {
 			Self::Poll(delay) => notify::PollWatcher::with_delay(Arc::new(Mutex::new(f)), delay)
 				.map(|w| Box::new(w) as _),
 		}
-		.map_err(|err| RuntimeError::FsWatcherCreate {
+		.map_err(|err| RuntimeError::FsWatcher {
 			kind: self,
+			err: FsWatcherError::Create {
 			help: if cfg!(target_os = "linux") && (matches!(err.kind, notify::ErrorKind::MaxFilesWatch) || matches!(err.kind, notify::ErrorKind::Io(ref ioerr) if ioerr.raw_os_error() == Some(28))) {
 				"you will want to increase your inotify.max_user_watches, see inotify(7) and https://watchexec.github.io/docs/inotify-limits.html"
 			} else if cfg!(target_os = "linux") && matches!(err.kind, notify::ErrorKind::Io(ref ioerr) if ioerr.raw_os_error() == Some(24)) {
@@ -61,7 +62,7 @@ impl Watcher {
 				"you may want to try again with the polling watcher"
 			}.into(),
 			err,
-		})
+		}})
 	}
 }
 
@@ -271,10 +272,13 @@ fn notify_multi_path_errors(
 			.unwrap_or_else(|| notify::Error::generic(&generic))
 			.add_path(path.clone());
 
-		errs.push(if rm {
-			RuntimeError::FsWatcherPathRemove { path, kind, err: e }
-		} else {
-			RuntimeError::FsWatcherPathAdd { path, kind, err: e }
+		errs.push(RuntimeError::FsWatcher {
+			kind,
+			err: if rm {
+				FsWatcherError::PathRemove { path, err: e }
+			} else {
+				FsWatcherError::PathAdd { path, err: e }
+			},
 		});
 	}
 
@@ -286,7 +290,10 @@ fn process_event(
 	kind: Watcher,
 	n_events: mpsc::Sender<Event>,
 ) -> Result<(), RuntimeError> {
-	let nev = nev.map_err(|err| RuntimeError::FsWatcherEvent { kind, err })?;
+	let nev = nev.map_err(|err| RuntimeError::FsWatcher {
+		kind,
+		err: FsWatcherError::Event(err),
+	})?;
 
 	let mut tags = Vec::with_capacity(4);
 	tags.push(Tag::Source(Source::Filesystem));