chore: add testing fakes for Distance Matrix

PiperOrigin-RevId: 577270364

src/testing/fake_distance_matrix.ts

@@ -0,0 +1,32 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export const FAKE_DM_VALUE = 101;
+
+/**
+ * Creates a fake Distance Matrix response, based on a map `fakeDistances` that
+ * specifies the resulting distance for a given _destination_ point. If a
+ * destination isn't found in the map, 101 is used as the distance.
+ */
+export function makeFakeDistanceMatrixResponse(
+    request: google.maps.DistanceMatrixRequest,
+    fakeDistances =
+        new Map<unknown, number>()): google.maps.DistanceMatrixResponse {
+  const rows: google.maps.DistanceMatrixResponseRow[] = [];
+  for (const _ of request.origins) {
+    const row = [];
+    for (const destination of request.destinations) {
+      const fakeValue = fakeDistances.get(destination) ?? FAKE_DM_VALUE;
+      const result = {
+        status: 'OK' as google.maps.DistanceMatrixElementStatus,
+        distance: {value: fakeValue, text: `${fakeValue} ${request.unitSystem}`}
+      } as google.maps.DistanceMatrixResponseElement;
+      row.push(result);
+    }
+    rows.push({elements: row});
+  }
+  return {originAddresses: [], destinationAddresses: [], rows};
+}

src/testing/fake_google_maps.ts

@@ -4,8 +4,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import {Place, PlaceResult} from '../utils/googlemaps_types.js';
+import {LatLng, LatLngLiteral, Place, PlaceResult} from '../utils/googlemaps_types.js';
 
+import {makeFakeDistanceMatrixResponse} from './fake_distance_matrix.js';
 import {makeFakePlace} from './fake_place.js';
 import {makeFakeRoute} from './fake_route.js';
 
@@ -38,6 +39,13 @@ export class FakeGoogleMapsHarness {
     routes: [makeFakeRoute()],
   } as google.maps.DirectionsResult);
 
+  /**
+   * Override this function to control the response of a
+   * `google.maps.DistanceMatrixService.getDistanceMatrix()` request.
+   */
+  distanceMatrixHandler = (request: google.maps.DistanceMatrixRequest) =>
+      makeFakeDistanceMatrixResponse(request);
+
   /**
    * Override this function to control the response of a
    * `google.maps.places.PlacesService.findPlaceFromQuery()` request.
@@ -138,7 +146,27 @@ export class FakeGoogleMapsHarness {
             return harness.routeHandler(request);
           }
         },
+
+        DistanceMatrixService: class {
+          getDistanceMatrix(request: google.maps.DistanceMatrixRequest) {
+            return Promise.resolve(harness.distanceMatrixHandler(request));
+          }
+        }
       },
+      'geometry': {
+        spherical: {
+          /**
+           * Fake spherical geometry calculation returns the difference in
+           * `lat` values.
+           */
+          computeDistanceBetween(
+              from: LatLng|LatLngLiteral, to: LatLng|LatLngLiteral): number {
+            const getLat = (x: LatLng|LatLngLiteral) =>
+                typeof x.lat === 'function' ? x.lat() : x.lat;
+            return Math.abs(getLat(from) - getLat(to));
+          }
+        }
+      }
     };
 
     this.sdk = {

src/utils/googlemaps_types.ts

@@ -62,5 +62,5 @@ export type PriceLevel = google.maps.places.PriceLevel;
 
 /** HTML tag names for Maps JS web components. */
 export interface HTMLElementTagNameMap {
-  'gmp-map': MapElement,
+  'gmp-map': MapElement;
 }