Normalise paths to unix on windows for filtering only (#558)

crates/cli/src/filterer/globset.rs

@@ -129,6 +129,100 @@ impl Filterer for WatchexecFilterer {
 			}
 		}
 
-		self.inner.check_event(event, priority)
+		#[cfg(windows)]
+		{
+			let normalised = windows_norm::normalise_event_to_unix(event, false);
+			trace!(event=?normalised, "check against unix-normalised event");
+			if !self.inner.check_event(&normalised, priority)? {
+				return Ok(false);
+			}
+
+			let prefixed_normalised = windows_norm::normalise_event_to_unix(event, true);
+			trace!(event=?prefixed_normalised, "check against prefixed unix-normalised event");
+			if !self.inner.check_event(&prefixed_normalised, priority)? {
+				return Ok(false);
+			}
+		}
+
+		trace!("check against original event");
+		if !self.inner.check_event(event, priority)? {
+			return Ok(false);
+		}
+
+		Ok(true)
+	}
+}
+
+#[cfg(windows)]
+mod windows_norm {
+	use std::{
+		ffi::OsString,
+		path::{Component, Path, PathBuf},
+	};
+	use watchexec_events::{Event, Tag};
+
+	pub fn normalise_event_to_unix(event: &Event, with_prefix: bool) -> Event {
+		let mut path_normalised_event = event.clone();
+		for mut tag in &mut path_normalised_event.tags {
+			if let Tag::Path { ref mut path, .. } = &mut tag {
+				*path = normalise_path_to_unix(path, with_prefix);
+			}
+		}
+		path_normalised_event
+	}
+
+	pub fn normalise_path_to_unix(path: &Path, with_prefix: bool) -> PathBuf {
+		let mut newpath = OsString::with_capacity(path.as_os_str().len());
+		let mut skip_root = false;
+		for component in path.components() {
+			if matches!(component, Component::Prefix(_)) {
+				if with_prefix {
+					newpath.push(component.as_os_str());
+					skip_root = true;
+				}
+			} else if matches!(component, Component::RootDir) && skip_root {
+				// skip
+			} else {
+				newpath.push("/");
+				newpath.push(component.as_os_str());
+			}
+		}
+
+		PathBuf::from(newpath)
+	}
+
+	#[cfg(test)]
+	#[test]
+	fn test_normalise_path_to_unix() {
+		assert_eq!(
+			normalise_path_to_unix(Path::new("C:\\Users\\foo\\bar"), false),
+			PathBuf::from("/Users/foo/bar")
+		);
+		assert_eq!(
+			normalise_path_to_unix(Path::new("C:\\Users\\foo\\bar"), true),
+			PathBuf::from("C:/Users/foo/bar")
+		);
+		assert_eq!(
+			normalise_path_to_unix(Path::new("E:\\_temp\\folder_to_watch\\private"), false),
+			PathBuf::from("/_temp/folder_to_watch/private")
+		);
+		assert_eq!(
+			normalise_path_to_unix(Path::new("E:\\_temp\\folder_to_watch\\private"), true),
+			PathBuf::from("E:/_temp/folder_to_watch/private")
+		);
+		assert_eq!(
+			normalise_path_to_unix(
+				Path::new("\\\\?\\E:\\_temp\\folder_to_watch\\public\\.hgignore"),
+				false
+			),
+			PathBuf::from("/_temp/folder_to_watch/public/.hgignore")
+		);
+		assert_eq!(
+			normalise_path_to_unix(
+				Path::new("\\\\?\\E:\\_temp\\folder_to_watch\\public\\.hgignore"),
+				true
+			),
+			PathBuf::from("\\\\?\\E:/_temp/folder_to_watch/public/.hgignore")
+		);
 	}
 }