be lazy when updating the ctx.filter property

Author: samizdatco

src/context/api.rs

@@ -1056,7 +1056,9 @@ pub fn set_filter(mut cx: FunctionContext) -> JsResult<JsUndefined> {
   let mut this = this.borrow_mut();
   if !cx.argument::<JsValue>(1)?.is_a::<JsNull, _>(&mut cx) {
     let (filter_text, specs) = filter_arg(&mut cx, 1)?;
-    this.state.filter = Filter::new(&filter_text, &specs);
+    if filter_text != this.state.filter.to_string() {
+      this.state.filter = Filter::new(&filter_text, &specs);
+    }
   }
   Ok(cx.undefined())
 }