fix: prevent selection compilers from side effecting selection defs

vega · Apr 29, 2022 · 045358c · 045358c
1 parent fb1010a
commit 045358c
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/compile/selection/parse.ts b/src/compile/selection/parse.ts
@@ -52,9 +52,10 @@ export function parseUnitSelection(model: UnitModel, selDefs: SelectionParameter
       events: isString(defaults.on) ? parseSelector(defaults.on, 'scope') : array(duplicate(defaults.on))
     } as any);
 
+    const def_ = duplicate(def); // defensive copy to prevent compilers from causing side effects
     for (const c of selectionCompilers) {
       if (c.defined(selCmpt) && c.parse) {
-        c.parse(model, selCmpt, def);
+        c.parse(model, selCmpt, def_);
       }
     }
   }