Compare target properties.

src/compare/diff.rs

@@ -3739,20 +3739,41 @@ fn compare_line_break<'b, 's>(
 }
 
 fn compare_target<'b, 's>(
-    _source: &'s str,
+    source: &'s str,
     emacs: &'b Token<'s>,
     rust: &'b Target<'s>,
 ) -> Result<DiffEntry<'b, 's>, Box<dyn std::error::Error>> {
-    let this_status = DiffStatus::Good;
-    let message = None;
+    let mut this_status = DiffStatus::Good;
+    let mut child_status = Vec::new();
+    let mut message = None;
 
-    // TODO: Compare :value
+    assert_no_children(emacs, &mut this_status, &mut message)?;
+
+    for diff in compare_properties!(
+        source,
+        emacs,
+        rust,
+        (
+            EmacsField::Required(":value"),
+            |r| Some(r.value),
+            compare_property_quoted_string
+        )
+    ) {
+        match diff {
+            ComparePropertiesResult::NoChange => {}
+            ComparePropertiesResult::SelfChange(new_status, new_message) => {
+                this_status = new_status;
+                message = new_message
+            }
+            ComparePropertiesResult::DiffEntry(diff_entry) => child_status.push(diff_entry),
+        }
+    }
 
     Ok(DiffResult {
         status: this_status,
         name: rust.get_elisp_name(),
         message,
-        children: Vec::new(),
+        children: child_status,
         rust_source: rust.get_source(),
         emacs_token: emacs,
     }