mapping a Seq to Seq[ReactElement] breaks Slinkly

[utenma]

in react is quite common to map an Array[any] to an Array[React Element], like this

render() {
    return (
      <div>
          {people.map((person, index) => (
              <p>Hello, {person.name} from {person.country}!</p>
          ))}
      </div>
   );
}

unfortunately, slinky breaks when trying to map a Seq[String] to a Seq[ReactElement]

like the following, it doesn't change no matter if you use ascription :*

iconNames = Seq("currency_exchange", "face")
...
  div()(
    iconNames.map(iconName => MaterialIcon(iconName, color="red")): _*
  )

Throwables.scala:18 Uncaught org.scalajs.linker.runtime.UndefinedBehaviorError: java.lang.ClassCastException: undefined is not an instance of scala.collection.immutable.Seq

however, using sequence of react elements directly without mapping works

div())(
  Seq (
    MaterialIcon("face"),
    MaterialIcon("currency_exchange"),
  )
)

i wonder if the problem may be caused by implicit conversions and how could a workaround be

[shadaj]

@saulpalv hmm, this is interesting. Perhaps I missed this, but what happens if you pass in the sequence directly without : _*? Although it should work correctly in both cases.

[shadaj]

Oh, wait, just noticed that iconNames is mutable in your example. It seems that iconNames may not have been initialized by the time you use it.