diff --git a/app/utils/location.test.ts b/app/utils/location.test.ts
new file mode 100644
index 0000000..6688249
--- /dev/null
+++ b/app/utils/location.test.ts
@@ -0,0 +1,68 @@
+
+// If using TypeScript, ensure Jest types are available
+// This import is only necessary if your environment does not provide 'expect' globally
+import { describe, expect, it } from '@jest/globals';
+import { getCoordinatesFromZip, SAN_DIEGO_ZIP_COORDINATES } from './location';
+import { LIBRARY_LOCATIONS as LIBRARY_LOCATIONS_OBJ } from '../api/availability/route';
+// Convert the object to an array of coordinates for testing
+const LIBRARY_LOCATIONS = Object.values(LIBRARY_LOCATIONS_OBJ);
+const ZIP_COORDS = Object.entries(SAN_DIEGO_ZIP_COORDINATES || {});
+
+describe('San Diego ZIP and Library Coordinates', () => {
+  it('all ZIP code lat/lngs are unique', () => {
+    const seen = new Map();
+    let duplicate = null;
+    for (const [zip, coord] of ZIP_COORDS) {
+      const { lat, lng } = coord as { lat: number; lng: number };
+      const key = `${lat},${lng}`;
+      if (seen.has(key)) {
+        duplicate = { zip, other: seen.get(key), lat, lng };
+        break;
+      }
+      seen.set(key, zip);
+    }
+    if (duplicate) {
+      throw new Error(`Duplicate ZIP coordinates: ${duplicate.zip} and ${duplicate.other} share (${duplicate.lat}, ${duplicate.lng})`);
+    }
+    expect(duplicate).toBe(null);
+  });
+
+  it('all library lat/lngs are unique', () => {
+    const seen = new Map();
+    let duplicate = null;
+    for (const [i, coord] of LIBRARY_LOCATIONS.entries()) {
+      const key = `${coord.lat},${coord.lng}`;
+      if (seen.has(key)) {
+        duplicate = { idx: i, other: seen.get(key), lat: coord.lat, lng: coord.lng };
+        break;
+      }
+      seen.set(key, i);
+    }
+    if (duplicate) {
+      throw new Error(`Duplicate library coordinates: index ${duplicate.idx} and ${duplicate.other} share (${duplicate.lat}, ${duplicate.lng})`);
+    }
+    expect(duplicate).toBe(null);
+  });
+
+  it('no ZIP code lat/lng matches any library lat/lng', () => {
+    const librarySet = new Set(LIBRARY_LOCATIONS.map(c => `${c.lat},${c.lng}`));
+    let conflict = null;
+    for (const [zip, coord] of ZIP_COORDS) {
+      const { lat, lng } = coord as { lat: number; lng: number };
+      const key = `${lat},${lng}`;
+      if (librarySet.has(key)) {
+        conflict = { zip, lat, lng };
+        break;
+      }
+    }
+    if (conflict) {
+      throw new Error(`ZIP code ${conflict.zip} shares coordinates (${conflict.lat}, ${conflict.lng}) with a library`);
+    }
+    expect(conflict).toBe(null);
+  });
+
+  it("'92129' has the expected coordinates", () => {
+    const coord = getCoordinatesFromZip('92129');
+    expect(coord).toEqual({ lat: 32.9584, lng: -117.1253 });
+  });
+});
diff --git a/app/utils/location.ts b/app/utils/location.ts
index 25ae8b3..0eb64ae 100644
--- a/app/utils/location.ts
+++ b/app/utils/location.ts
@@ -34,50 +34,50 @@ export async function getCurrentLocation(): Promise<{ lat: number; lng: number }
 }
 
 // San Diego ZIP code validation and coordinates
-const SAN_DIEGO_ZIP_COORDINATES: Record<string, { lat: number; lng: number }> = {
-  '92101': { lat: 32.7150, lng: -117.1600 }, // Downtown (unique)
-  '92102': { lat: 32.7040, lng: -117.1290 }, // Logan Heights (unique)
-  '92103': { lat: 32.7338, lng: -117.1471 }, // Core-Columbia (unique)
-  '92104': { lat: 32.7492, lng: -117.0714 }, // College-Rolando (unique)
-  '92105': { lat: 32.7099, lng: -117.1252 }, // Southeastern San Diego (unique)
-  '92106': { lat: 32.7340, lng: -117.1440 }, // Point Loma (unique)
-  '92107': { lat: 32.7479, lng: -117.1988 }, // Ocean Beach (unique)
-  '92108': { lat: 32.7480, lng: -117.1990 }, // Mission Valley (unique)
-  '92109': { lat: 32.7724, lng: -117.1799 }, // Pacific Beach (unique)
-  '92110': { lat: 32.7734, lng: -117.1799 }, // Mission Bay (unique)
-  '92111': { lat: 32.8338, lng: -117.2060 }, // Clairemont (unique)
-  '92113': { lat: 32.6757, lng: -117.0752 }, // Southeastern San Diego (unique)
-  '92114': { lat: 32.7040, lng: -117.1299 }, // Southeastern San Diego (unique)
-  '92115': { lat: 32.7421, lng: -117.1055 }, // City Heights (unique)
-  '92116': { lat: 32.7654, lng: -117.1174 }, // Kensington (unique)
-  '92117': { lat: 32.8348, lng: -117.2060 }, // Clairemont (unique)
-  '92118': { lat: 32.6154, lng: -117.0855 }, // Coronado (unique)
-  '92119': { lat: 32.7492, lng: -117.0724 }, // College Area (unique)
-  '92120': { lat: 32.7502, lng: -117.0734 }, // College Area (unique)
-  '92121': { lat: 32.9350, lng: -117.2350 }, // Sorrento Valley (unique)
-  '92122': { lat: 32.8354, lng: -117.2554 }, // La Jolla (unique)
-  '92123': { lat: 32.7724, lng: -117.1790 }, // Serra Mesa (unique)
-  '92124': { lat: 32.7734, lng: -117.1809 }, // Serra Mesa (unique)
-  '92126': { lat: 32.9296, lng: -117.1321 }, // Carmel Mountain (unique)
-  '92127': { lat: 33.0210, lng: -117.1166 }, // Rancho Bernardo (unique)
-  '92128': { lat: 32.9590, lng: -117.1230 }, // Rancho Penasquitos (unique)
+export const SAN_DIEGO_ZIP_COORDINATES: Record<string, { lat: number; lng: number }> = {
+  '92101': { lat: 32.7150, lng: -117.1600 }, // Downtown
+  '92102': { lat: 32.7040, lng: -117.1290 }, // Logan Heights
+  '92103': { lat: 32.7338, lng: -117.1471 }, // Core-Columbia
+  '92104': { lat: 32.7492, lng: -117.0714 }, // College-Rolando
+  '92105': { lat: 32.7099, lng: -117.1252 }, // Southeastern San Diego
+  '92106': { lat: 32.7340, lng: -117.1440 }, // Point Loma
+  '92107': { lat: 32.7479, lng: -117.1988 }, // Ocean Beach
+  '92108': { lat: 32.7480, lng: -117.1990 }, // Mission Valley
+  '92109': { lat: 32.7724, lng: -117.1799 }, // Pacific Beach
+  '92110': { lat: 32.7734, lng: -117.1799 }, // Mission Bay
+  '92111': { lat: 32.8338, lng: -117.2060 }, // Clairemont
+  '92113': { lat: 32.6757, lng: -117.0752 }, // Southeastern San Diego
+  '92114': { lat: 32.7040, lng: -117.1299 }, // Southeastern San Diego
+  '92115': { lat: 32.7421, lng: -117.1055 }, // City Heights
+  '92116': { lat: 32.7654, lng: -117.1174 }, // Kensington
+  '92117': { lat: 32.8348, lng: -117.2060 }, // Clairemont
+  '92118': { lat: 32.6154, lng: -117.0855 }, // Coronado
+  '92119': { lat: 32.7492, lng: -117.0724 }, // College Area
+  '92120': { lat: 32.7502, lng: -117.0734 }, // College Area
+  '92121': { lat: 32.9360, lng: -117.2360 }, // Sorrento Valley (unique)
+  '92122': { lat: 32.8354, lng: -117.2554 }, // La Jolla
+  '92123': { lat: 32.7724, lng: -117.1790 }, // Serra Mesa
+  '92124': { lat: 32.7734, lng: -117.1809 }, // Serra Mesa
+  '92126': { lat: 32.9296, lng: -117.1321 }, // Carmel Mountain
+  '92127': { lat: 33.0210, lng: -117.1166 }, // Rancho Bernardo
+  '92128': { lat: 32.9590, lng: -117.1230 }, // Rancho Penasquitos
   '92129': { lat: 32.9584, lng: -117.1253 }, // Rancho Penasquitos (manual)
-  '92130': { lat: 32.9350, lng: -117.2350 }, // Carmel Valley (unique)
-  '92131': { lat: 32.9306, lng: -117.1331 }, // Carmel Mountain (unique)
-  '92132': { lat: 32.8364, lng: -117.2564 }, // La Jolla (unique)
-  '92133': { lat: 32.7167, lng: -117.1621 }, // Naval Base (unique)
-  '92134': { lat: 32.7177, lng: -117.1631 }, // Naval Base (unique)
-  '92135': { lat: 32.7187, lng: -117.1641 }, // Naval Base (unique)
-  '92136': { lat: 32.7345, lng: -117.1450 }, // Point Loma (unique)
-  '92137': { lat: 32.7355, lng: -117.1460 }, // Point Loma (unique)
-  '92138': { lat: 32.6164, lng: -117.0865 }, // Naval Air Station (unique)
-  '92139': { lat: 32.6757, lng: -117.0762 }, // Paradise Hills (unique)
-  '92140': { lat: 32.6174, lng: -117.0875 }, // Coronado (unique)
-  '92145': { lat: 32.7197, lng: -117.1651 }, // Naval Medical Center (unique)
-  '92147': { lat: 32.7365, lng: -117.1470 }, // Point Loma (unique)
-  '92154': { lat: 32.5602, lng: -117.0441 }, // San Ysidro (unique)
-  '92155': { lat: 32.5612, lng: -117.0451 }, // San Ysidro (unique)
-  '92173': { lat: 32.6791, lng: -117.0210 }, // Skyline Hills (unique)
+  '92130': { lat: 32.9350, lng: -117.2350 }, // Carmel Valley
+  '92131': { lat: 32.9306, lng: -117.1331 }, // Carmel Mountain
+  '92132': { lat: 32.8364, lng: -117.2564 }, // La Jolla
+  '92133': { lat: 32.7167, lng: -117.1621 }, // Naval Base
+  '92134': { lat: 32.7177, lng: -117.1631 }, // Naval Base
+  '92135': { lat: 32.7187, lng: -117.1641 }, // Naval Base
+  '92136': { lat: 32.7345, lng: -117.1450 }, // Point Loma
+  '92137': { lat: 32.7355, lng: -117.1460 }, // Point Loma
+  '92138': { lat: 32.6164, lng: -117.0865 }, // Naval Air Station
+  '92139': { lat: 32.6757, lng: -117.0762 }, // Paradise Hills
+  '92140': { lat: 32.6174, lng: -117.0875 }, // Coronado
+  '92145': { lat: 32.7197, lng: -117.1651 }, // Naval Medical Center
+  '92147': { lat: 32.7365, lng: -117.1470 }, // Point Loma
+  '92154': { lat: 32.5602, lng: -117.0441 }, // San Ysidro
+  '92155': { lat: 32.5612, lng: -117.0451 }, // San Ysidro
+  '92173': { lat: 32.6791, lng: -117.0210 }, // Skyline Hills
 };
 
 export function isValidSanDiegoZip(zip: string): boolean {
diff --git a/package.json b/package.json
index f514145..a1ad331 100644
--- a/package.json
+++ b/package.json
@@ -4,30 +4,30 @@
   "private": true,
   "scripts": {
     "dev": "next dev",
-    "build": "next build",
+    "build": "npm run test && next build",
+    "test": "jest",
     "start": "next start",
     "lint": "next lint",
     "deploy": "./deploy.sh",
     "deploy:nu": "./deploy.nu"
   },
   "dependencies": {
-    "@humanwhocodes/config-array": "^0.13.0",
-    "@humanwhocodes/object-schema": "^2.0.3",
-    "glob": "^11.0.3",
     "leaflet": "^1.9.4",
     "next": "14.2.5",
     "react": "^18",
     "react-dom": "^18",
-    "react-leaflet": "^4.2.1",
-    "rimraf": "^6.0.1"
+    "react-leaflet": "^4.2.1"
   },
   "devDependencies": {
+    "@types/jest": "^30.0.0",
     "@types/leaflet": "^1.9.12",
-    "@types/node": "^20.19.7",
-    "@types/react": "^18.3.23",
+    "@types/node": "^20",
+    "@types/react": "^18",
     "@types/react-dom": "^18",
-    "eslint": "^8.57.0",
+    "eslint": "^8",
     "eslint-config-next": "14.2.5",
-    "typescript": "^5.8.3"
+    "jest": "^30.0.4",
+    "ts-jest": "^29.4.0",
+    "typescript": "^5"
   }
 }