Add initial region loading for supported systems

Expose an initialRegion field on the System GraphQL type so the app can
display the correct campus area on first load instead of a zoomed-out
default map view. Chapman University is configured with coordinates
centered on campus.

https://claude.ai/code/session_0162emnCi1KxW5FkTNn2ZrvH

schema.graphqls

@@ -6,6 +6,7 @@ scalar DateTime
 type System {
   id: ID!
   name: String!
+  initialRegion: Region
   routes: [Route!]
   route(id: ID): Route
   stops: [Stop!]
@@ -16,6 +17,13 @@ type System {
   parkingSystem: ParkingSystem
 }
 
+type Region {
+  latitude: Float!
+  longitude: Float!
+  latitudeDelta: Float!
+  longitudeDelta: Float!
+}
+
 type ParkingSystem {
   systemId: ID!
   parkingStructures: [ParkingStructure!]

src/entities/InterchangeSystem.ts

@@ -19,6 +19,7 @@ import { InMemoryExternalSourceETARepository } from "../repositories/shuttle/eta
 import { ETAGetterRepository } from "../repositories/shuttle/eta/ETAGetterRepository";
 import { InMemorySelfUpdatingETARepository } from "../repositories/shuttle/eta/InMemorySelfUpdatingETARepository";
 import { BaseInMemoryETARepository } from "../repositories/shuttle/eta/BaseInMemoryETARepository";
+import { IRegion } from "./SharedEntities";
 
 export interface InterchangeSystemBuilderArguments {
   name: string;
@@ -49,6 +50,12 @@ export interface InterchangeSystemBuilderArguments {
    * at a stop, in latitude/longitude degrees.
    */
   shuttleStopArrivalDegreeDelta: number;
+
+  /**
+   * The initial map region to display when the app first loads
+   * this system. Represents a center coordinate and span.
+   */
+  initialRegion?: IRegion;
 }
 
 export class InterchangeSystem {
@@ -62,6 +69,7 @@ export class InterchangeSystem {
     public notificationRepository: NotificationRepository,
     public parkingTimedDataLoader: TimedApiBasedRepositoryLoader | null,
     public parkingRepository: ParkingGetterSetterRepository | null,
+    public initialRegion: IRegion | null,
   ) {
   }
 
@@ -96,6 +104,7 @@ export class InterchangeSystem {
       notificationRepository,
       timedParkingLoader,
       parkingRepository,
+      args.initialRegion ?? null,
     );
   }
 
@@ -205,6 +214,7 @@ export class InterchangeSystem {
       notificationRepository,
       timedParkingLoader,
       parkingRepository,
+      args.initialRegion ?? null,
     );
   }
 

src/entities/SharedEntities.ts

@@ -11,3 +11,10 @@ export interface ICoordinates {
   longitude: number;
 }
 
+export interface IRegion {
+  latitude: number;
+  longitude: number;
+  latitudeDelta: number;
+  longitudeDelta: number;
+}
+

src/index.ts

@@ -25,6 +25,12 @@ const supportedSystems: InterchangeSystemBuilderArguments[] = [
     name: "Chapman University",
     useSelfUpdatingEtas: true,
     shuttleStopArrivalDegreeDelta: 0.001,
+    initialRegion: {
+      latitude: 33.7937,
+      longitude: -117.8531,
+      latitudeDelta: 0.01,
+      longitudeDelta: 0.01,
+    },
   }
 ]
 

src/resolvers/SystemResolvers.ts

@@ -83,6 +83,14 @@ export const SystemResolvers: Resolvers<ServerContext> = {
       const shuttles = await system.shuttleRepository.getShuttles();
       return shuttles.slice().sort((a, b) => a.name.localeCompare(b.name));
     },
+    initialRegion: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return null;
+      }
+
+      return system.initialRegion;
+    },
     parkingSystem: async (parent, _args, contextValue, _info) => {
       const system = contextValue.findSystemById(parent.id);
       if (!system) {

src/resolvers/__tests__/SystemResolverTests.test.ts

@@ -35,6 +35,35 @@ describe("SystemResolvers", () => {
     });
   }
 
+  describe("initialRegion", () => {
+    const query = `
+    query GetSystemInitialRegion($systemId: ID!) {
+      system(id: $systemId) {
+        initialRegion {
+          latitude
+          longitude
+          latitudeDelta
+          longitudeDelta
+        }
+      }
+    }
+    `;
+
+    it("returns the initial region for the system", async () => {
+      const response = await getResponseFromQueryNeedingSystemId(query);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+      const initialRegion = (response.body.singleResult.data as any).system.initialRegion;
+      expect(initialRegion).toEqual({
+        latitude: 33.7937,
+        longitude: -117.8531,
+        latitudeDelta: 0.01,
+        longitudeDelta: 0.01,
+      });
+    });
+  });
+
   describe("routes", () => {
     const query = `
     query GetSystemRoutes($systemId: ID!) {

testHelpers/apolloTestServerHelpers.ts

@@ -26,6 +26,12 @@ const systemInfoForTesting: InterchangeSystemBuilderArguments = {
   parkingSystemId: ChapmanApiBasedParkingRepositoryLoader.id,
   useSelfUpdatingEtas: false,
   shuttleStopArrivalDegreeDelta: 0.001,
+  initialRegion: {
+    latitude: 33.7937,
+    longitude: -117.8531,
+    latitudeDelta: 0.01,
+    longitudeDelta: 0.01,
+  },
 };
 
 export function buildSystemForTesting() {