fix: assume geolocation permission state in iOS <= 15 based on geoloc…

…ation feature presence

Don't use unsupported permission queries.

src/lib/components/Map/Map.svelte

@@ -160,10 +160,32 @@
       }
     }
 
-    const geolocationPermission =
-      'geolocation' in navigator
-        ? await navigator.permissions.query({ name: 'geolocation' }).then((result) => result.state)
-        : 'not-available';
+    let geolocationPermission: string;
+
+    // We noticed a bug where the map broke on iOS 15.2 due to "query" not existing on the permissions
+    // object; while it actually supports geolocation
+    //
+    // From:  https://github.com/mapbox/mapbox-gl-js/blob/d8827408c6f4c4ceecba517931c96dda8bb261a1/src/ui/control/geolocate_control.js#L175-L177
+    // > navigator.permissions has incomplete browser support http://caniuse.com/#feat=permissions-api
+    // > Test for the case where a browser disables Geolocation because of an insecure origin;
+    // > in some environments like iOS16 WebView, permissions reject queries but still support geolocation
+    const geolocationObjectExists = !!navigator.geolocation;
+    // on iOS <= 16, I don't think we can know the state. But 'prompt' is safe to assume?
+    // because actually attempting a geolocation may result in a prompt / error / location
+    // The purpose of this `geolocationPermission` is to decide whether or not to add the
+    // geolocation control, and whether or not to try to trigger it automatically (see further on).
+    const assumedState = geolocationObjectExists ? 'prompt' : 'not-available';
+    if ('geolocation' in navigator && navigator?.permissions?.query !== undefined) {
+      // Query if possible
+      geolocationPermission = await navigator.permissions
+        .query({ name: 'geolocation' })
+        .then((result) => result.state)
+        // fall back to assumed state
+        .catch(() => assumedState);
+    } else {
+      // fall back to assumed state if queries are not possible
+      geolocationPermission = assumedState;
+    }
 
     addMap();