fix events typing

apps/examples/src/examples/Example-MapEvents.vue

@@ -2,7 +2,7 @@
 import { onMounted, ref } from 'vue'
 import Map from 'ol/Map'
 import { createMapFromContext, listen } from '@geospatial-sdk/openlayers'
-import type { FeaturesHoverEvent, MapClickEvent, MapContext } from '@geospatial-sdk/core'
+import type { MapContext } from '@geospatial-sdk/core'
 import { DEFAULT_CONTEXT } from '@/constants'
 import Panel from '@/components/Panel.vue'
 import type { Feature } from 'geojson'
@@ -30,8 +30,8 @@ let clickCoordinates = ref<[number, number] | null>(null)
 
 onMounted(async () => {
   map = await createMapFromContext(context, mapRoot.value)
-  listen(map, 'features-hover', (event: FeaturesHoverEvent) => (features.value = event.features))
-  listen(map, 'map-click', (event: MapClickEvent) => (clickCoordinates.value = event.coordinate))
+  listen(map, 'features-hover', (event) => (features.value = event.features))
+  listen(map, 'map-click', (event) => (clickCoordinates.value = event.coordinate))
 })
 </script>
 

packages/core/lib/model/events.ts

@@ -2,22 +2,24 @@ import { Feature } from "geojson";
 
 export const FeaturesClickEventType = "features-click";
 export interface FeaturesClickEvent {
+  type: typeof FeaturesClickEventType;
   features: Feature[];
 }
 
 export const FeaturesHoverEventType = "features-hover";
 export interface FeaturesHoverEvent {
+  type: typeof FeaturesHoverEventType;
   features: Feature[];
 }
 
 export const MapClickEventType = "map-click";
 export interface MapClickEvent {
+  type: typeof MapClickEventType;
   coordinate: [number, number]; // expressed in lon/lat
 }
 
-export type MapEvent = FeaturesClickEvent | FeaturesHoverEvent | MapClickEvent;
-
-export type MapEventType =
-  | typeof FeaturesClickEventType
-  | typeof FeaturesHoverEventType
-  | typeof MapClickEventType;
+export interface MapEventsByType {
+  [FeaturesClickEventType]: FeaturesClickEvent;
+  [FeaturesHoverEventType]: FeaturesHoverEvent;
+  [MapClickEventType]: MapClickEvent;
+}

packages/openlayers/lib/map/register-events.test.ts

@@ -190,7 +190,10 @@ describe("event registration", () => {
       map.dispatchEvent(createMapEvent(map, "click"));
     });
     it("registers the event on the map", () => {
-      expect(callback).toHaveBeenCalledWith({ coordinate: toLonLat([10, 10]) });
+      expect(callback).toHaveBeenCalledWith({
+        coordinate: toLonLat([10, 10]),
+        type: "map-click",
+      });
     });
   });
 });

packages/openlayers/lib/map/register-events.ts

@@ -3,8 +3,7 @@ import {
   FeaturesClickEventType,
   FeaturesHoverEventType,
   MapClickEventType,
-  MapEvent,
-  MapEventType,
+  MapEventsByType,
 } from "@geospatial-sdk/core";
 import { toLonLat } from "ol/proj";
 import GeoJSON from "ol/format/GeoJSON";
@@ -121,24 +120,24 @@ function registerFeatureHoverEvent(map: Map) {
   map.set(FeaturesHoverEventType, true);
 }
 
-export function listen(
+export function listen<T extends keyof MapEventsByType>(
   map: Map,
-  event: MapEventType,
-  callback: (event: MapEvent) => void,
+  eventType: T,
+  callback: (event: MapEventsByType[T]) => void,
 ) {
-  switch (event) {
+  switch (eventType) {
     case FeaturesClickEventType:
       registerFeatureClickEvent(map);
       // we're using a custom event type here so we need to cast to unknown first
-      map.on(event as unknown as MapObjectEventTypes, (event) => {
-        callback(event as unknown as MapEvent);
+      map.on(eventType as unknown as MapObjectEventTypes, (event) => {
+        (callback as (event: unknown) => void)(event);
       });
       break;
     case FeaturesHoverEventType:
       registerFeatureHoverEvent(map);
       // see comment above
-      map.on(event as unknown as MapObjectEventTypes, (event) => {
-        callback(event as unknown as MapEvent);
+      map.on(eventType as unknown as MapObjectEventTypes, (event) => {
+        (callback as (event: unknown) => void)(event);
       });
       break;
     case MapClickEventType:
@@ -147,10 +146,13 @@ export function listen(
           event.pixel,
           map.getView().getProjection(),
         ) as [number, number];
-        callback({ coordinate });
+        (callback as (event: unknown) => void)({
+          type: "map-click",
+          coordinate,
+        });
       });
       break;
     default:
-      throw new Error(`Unrecognized event type: ${event}`);
+      throw new Error(`Unrecognized event type: ${eventType}`);
   }
 }