diff --git a/src/testing/fake_gmp_components.ts b/src/testing/fake_gmp_components.ts
index 8cb2bc6..870a346 100644
--- a/src/testing/fake_gmp_components.ts
+++ b/src/testing/fake_gmp_components.ts
@@ -27,5 +27,8 @@ declare global {
 }
 
 export class FakeMapElement extends LitElement {
-  readonly innerMap = {} as google.maps.Map;
+  readonly innerMap = {
+    fitBounds:
+        (bounds: google.maps.LatLngBounds|google.maps.LatLngBoundsLiteral) => {}
+  } as google.maps.Map;
 }
diff --git a/src/testing/fake_lat_lng.ts b/src/testing/fake_lat_lng.ts
index 8b3750a..864221b 100644
--- a/src/testing/fake_lat_lng.ts
+++ b/src/testing/fake_lat_lng.ts
@@ -40,14 +40,22 @@ export class FakeLatLng implements LatLng {
   }
 }
 
+function isLatLngBoundsLiteral(bounds: LatLngBounds|LatLngBoundsLiteral):
+    bounds is LatLngBoundsLiteral {
+  return (typeof (bounds as LatLngBoundsLiteral).north === 'number');
+}
+
 /**
  * A fake `LatLngBounds` class for testing purposes, that does not depend on the
  * `google.maps.LatLngBounds` constructor loaded by the API.
  */
 export class FakeLatLngBounds implements LatLngBounds {
-  constructor(
-      private readonly boundsLiteral:
-          LatLngBoundsLiteral = {north: 0, south: 0, east: 0, west: 0}) {}
+  constructor(private readonly boundsLiteral: LatLngBoundsLiteral = {
+    north: -90,
+    south: 90,
+    east: -180,
+    west: 180
+  }) {}
 
   getNorthEast(): LatLng {
     return new FakeLatLng(this.boundsLiteral.north, this.boundsLiteral.east);
@@ -58,6 +66,15 @@ export class FakeLatLngBounds implements LatLngBounds {
   toJSON(): LatLngBoundsLiteral {
     return this.boundsLiteral;
   }
+  union(other: LatLngBounds|LatLngBoundsLiteral): LatLngBounds {
+    const {north, south, east, west} = this.boundsLiteral;
+    const otherLiteral = isLatLngBoundsLiteral(other) ? other : other.toJSON();
+    this.boundsLiteral.north = Math.max(north, otherLiteral.north);
+    this.boundsLiteral.south = Math.min(south, otherLiteral.south);
+    this.boundsLiteral.east = Math.max(east, otherLiteral.east);
+    this.boundsLiteral.west = Math.min(west, otherLiteral.west);
+    return this;
+  }
 
   contains(latLng: LatLng|LatLngLiteral): boolean {
     throw new Error('contains is not implemented');
@@ -83,7 +100,4 @@ export class FakeLatLngBounds implements LatLngBounds {
   toUrlValue(precision?: number): string {
     throw new Error('toUrlValue is not implemented');
   }
-  union(other: LatLngBounds|LatLngBoundsLiteral): LatLngBounds {
-    throw new Error('union is not implemented');
-  }
 }
diff --git a/src/testing/fake_route.ts b/src/testing/fake_route.ts
index 39d32e1..6a71f3e 100644
--- a/src/testing/fake_route.ts
+++ b/src/testing/fake_route.ts
@@ -34,8 +34,8 @@ const EMPTY_FAKE_LEG: DirectionsLeg = {
  * Makes a fake `google.maps.DirectionsRoute` object for testing purposes.
  *
  * @param fields - An object of fields of the `DirectionsRoute`. Any fields not
- *     provided will default to empty strings, empty arrays, or the LatLngBounds
- *     0/0/0/0.
+ *     provided will default to empty strings, empty arrays, or an empty
+ *     LatLngBounds.
  */
 export function makeFakeRoute(fields: Partial<DirectionsRoute> = {}):
     DirectionsRoute {