HighlightOptions

// Use the default highlights collection to apply a highlight to features when you hover over them

// A handler can be used to remove any previous highlight when applying a new one
let hoverHighlight;

view.on("pointer-move", (event) => {
  // Search for features in the featureLayer at the hovered location
  view.hitTest(event, { include: featureLayer }).then((response) => {
    if (response.results.length) {
      const features = response.results.map(result => result.graphic);
      // Remove any previous highlight, if it exists
      hoverHighlight?.remove();
      // Highlight the hit features with the temporary highlight options, which are pre-configured for this use case
      hoverHighlight = layerView.highlight(features, {name: "temporary"});
    }
  }).catch((error) => {
    console.error("Error during hitTest:", error);
  });

// SceneView highlights with shadow settings configured
const view = new SceneView({
  map: map,
  highlights: [
    {
      name: "oaks"
      color: "forestgreen",
      haloColor: "green",
      haloOpacity: 0.9,
      fillOpacity: 0.2,
      shadowColor: "goldenrod",
      shadowOpacity: 0.5
    }
  ]
});

// A handler can be used to remove any previous highlight when applying a new one
let highlight;

// Query for particualar features in a layer and then highlight them with the specified options
view.whenLayerView(treesLayer).then((layerView) => {
  let query = treesLayer.createQuery();
  query.where = "type = 'Quercus'";
  treesLayer.queryFeatures(query).then((result) => {
    // Remove any previous highlight, if it exists
    highlight?.remove();
    // Apply the user-defined "oaks" highlight options to the corresponding tree features
    highlight = layerView.highlight(result.features, {name: "oaks"});
  });
});