Add TryIntoJsResult for vectors (#3993)

* Add TryIntoJsResult for vectors

This way JsFunction made with into_js_function can return vectors.

* Fix build error

core/engine/src/try_into_js_result_impls.rs

@@ -1,5 +1,6 @@
 //! Declare implementations of [`TryIntoJsResult`] trait for various types.
 
+use crate::object::JsArray;
 use crate::{Context, JsResult, JsValue, TryIntoJsResult};
 
 impl<T> TryIntoJsResult for T
@@ -11,6 +12,20 @@ where
     }
 }
 
+impl<T> TryIntoJsResult for Vec<T>
+where
+    T: TryIntoJsResult,
+{
+    fn try_into_js_result(self, cx: &mut Context) -> JsResult<JsValue> {
+        let array = JsArray::new(cx);
+        // We have to manually enumerate because we cannot return a Result from a map monad.
+        for value in self {
+            array.push(value.try_into_js_result(cx)?, cx)?;
+        }
+        Ok(array.into())
+    }
+}
+
 impl<T> TryIntoJsResult for Option<T>
 where
     T: TryIntoJsResult,