Extract reconcile (#85)

sync-server/src/utils/sanitize_path.rs

@@ -0,0 +1,34 @@
+/// Sanitize the document's path to allow all clients to create the same path in
+/// their filesystem. If we didn't do this server-side, client's would need to
+/// deal with mapping invalid names to valid ones and then back.
+pub fn sanitize_path(path: &str) -> String {
+    let options = sanitize_filename::Options {
+        truncate: true,
+        windows: true, // Windows is the lowest common denominator
+        replacement: "",
+    };
+
+    path.split('/')
+        .map(|part| {
+            let proposal = sanitize_filename::sanitize_with_options(part, options.clone());
+            if !part.is_empty() && proposal.is_empty() {
+                "_".to_owned()
+            } else {
+                proposal
+            }
+        })
+        .collect::<Vec<_>>()
+        .join("/")
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_sanitize_path() {
+        assert_eq!(sanitize_path("/my/path/what?"), "/my/path/what");
+        assert_eq!(sanitize_path("file (1).md"), "file (1).md");
+        assert_eq!(sanitize_path("/my/path/\\\\:?"), "/my/path/_");
+    }
+}