Compare document category.

src/compare/diff.rs

@@ -438,7 +438,28 @@ pub fn compare_document<'s>(
         Ok(_) => {}
     }
 
-    // TODO: Compare :path :CATEGORY
+    // TODO: Compare :path
+
+    // Compare category
+    let category = get_property_quoted_string(emacs, ":CATEGORY")?;
+    match (category.as_ref(), rust.category) {
+        (None, None) => {}
+        (None, Some(_)) | (Some(_), None) => {
+            this_status = DiffStatus::Bad;
+            message = Some(format!(
+                "Category mismatch (emacs != rust) {:?} != {:?}",
+                category, rust.category
+            ));
+        }
+        (Some(e), Some(r)) if e != r => {
+            this_status = DiffStatus::Bad;
+            message = Some(format!(
+                "Category mismatch (emacs != rust) {:?} != {:?}",
+                category, rust.category
+            ));
+        }
+        (Some(_), Some(_)) => {}
+    };
 
     // Skipping "org-data" and its properties
     for (i, token) in children.iter().skip(2).enumerate() {