Now ensuring we are fetching the centerpoint of a geohash rather than…

… a random point within it

README.md

@@ -177,6 +177,8 @@ You can bypass the cache and force a fresh request to the provider by setting th
 const weather = await weatherPlus.getWeather(51.5074, -0.1278, { bypassCache: true });
 ```
 
+This will not entirely bypass the cache, it bypasses it for the read request and then the returned data is cached again for future use.
+
 ### Geohash Precision
 
 The library uses geohashing to cache weather data for nearby locations efficiently. Geohashing converts latitude and longitude into a short alphanumeric string, representing an area on the Earth’s surface.

src/index.test.ts

@@ -1,5 +1,6 @@
 import WeatherPlus from './index';
 import axios from 'axios';
+import geohash from 'ngeohash';
 import MockAdapter from 'axios-mock-adapter';
 import { IWeatherData } from './interfaces';
 import { InvalidProviderLocationError } from './errors';
@@ -99,8 +100,9 @@ describe('WeatherPlus Library', () => {
       },
     ];
 
+    const { latitude, longitude } = geohash.decode(geohash.encode(lat, lng, 5));
     // Mock NWS API responses
-    mock.onGet(`https://api.weather.gov/points/${lat},${lng}`).reply(200, mockResponses[0]);
+    mock.onGet(`https://api.weather.gov/points/${latitude},${longitude}`).reply(200, mockResponses[0]);
     mock
       .onGet('https://api.weather.gov/gridpoints/OKX/33,35/stations')
       .reply(200, mockResponses[1]);
@@ -194,8 +196,10 @@ describe('WeatherPlus Library', () => {
     const lat = 51.5074; // London, UK
     const lng = -0.1278;
 
+    const { latitude, longitude } = geohash.decode(geohash.encode(lat, lng, 5));
+
     // Mock NWS to throw an error
-    mock.onGet(`https://api.weather.gov/points/${lat},${lng}`).reply(500);
+    mock.onGet(`https://api.weather.gov/points/${latitude},${longitude}`).reply(500);
     // Mock OpenWeather to return 500
     mock
       .onGet('https://api.openweathermap.org/data/3.0/onecall')
@@ -259,8 +263,10 @@ describe('WeatherPlus Library', () => {
       },
     ];
 
+    const { latitude, longitude } = geohash.decode(geohash.encode(lat, lng, 5));
+
     // Mock NWS API responses
-    mock.onGet(`https://api.weather.gov/points/${lat},${lng}`).reply(200, mockResponses[0]);
+    mock.onGet(`https://api.weather.gov/points/${latitude},${longitude}`).reply(200, mockResponses[0]);
     mock
       .onGet('https://api.weather.gov/gridpoints/OKX/33,35/stations')
       .reply(200, mockResponses[1]);

src/weatherService.test.ts

@@ -2,6 +2,7 @@ import { WeatherService, GetWeatherOptions } from './weatherService';
 import { InvalidProviderLocationError } from './errors';
 import { IWeatherUnits, IWeatherData } from './interfaces';
 import { IWeatherProvider } from './providers/IWeatherProvider';
+import geohash from 'ngeohash';
 
 jest.mock('./cache', () => {
   return {
@@ -242,7 +243,6 @@ describe('WeatherService', () => {
   });
 
   it('should verify that the provider name is included in the weather data', async () => {
-    // Arrange
     const lat = 37.7749; // San Francisco
     const lng = -122.4194;
 
@@ -271,7 +271,8 @@ describe('WeatherService', () => {
     const result = await weatherService.getWeather(lat, lng);
 
     // Assert
-    expect(mockProvider.getWeather).toHaveBeenCalledWith(lat, lng);
+    const { latitude, longitude } = geohash.decode(geohash.encode(lat, lng, 5));
+    expect(mockProvider.getWeather).toHaveBeenCalledWith(latitude, longitude);
     expect(result).toEqual(mockWeatherData);
     expect(result.provider).toBe('openweather'); // Verify provider name
   });
@@ -304,8 +305,9 @@ describe('WeatherService', () => {
     // Expect cache.get not to be called
     expect(mockCache.get).not.toHaveBeenCalled();
 
+    const { latitude, longitude } = geohash.decode(geohash.encode(0, 0, 5));
     // Expect provider.getWeather to be called
-    expect(mockProvider.getWeather).toHaveBeenCalledWith(0, 0);
+    expect(mockProvider.getWeather).toHaveBeenCalledWith(latitude, longitude);
 
     // Expect cache.set to be called with new data
     expect(mockCache.set).toHaveBeenCalledWith(expect.any(String), JSON.stringify(result));

src/weatherService.ts

@@ -99,16 +99,25 @@ export class WeatherService {
       try {
         log(`Trying provider ${provider.name} for (${lat}, ${lng})`);
 
+        // Convert geohash to lat/lng using ngeohash
+        // This ensures that the lat/lng we are pulling weather from is the center of the geohash
+        // rather than the original lat/lng that was passed in that could be on the edge of the geohash.
+        const {
+          latitude: geohashLat,
+          longitude: geohashLng
+        } = geohash.decode(locationGeohash);
+        log(`Using geohash center point: (${geohashLat}, ${geohashLng})`);
+
         // Check if provider supports the given location (e.g., NWS only supports US locations)
-        if (provider.name === 'nws' && !isLocationInUS(lat, lng)) {
-          log(`Provider ${provider.name} does not support location (${lat}, ${lng})`);
+        if (provider.name === 'nws' && !isLocationInUS(geohashLat, geohashLng)) {
+          log(`Provider ${provider.name} does not support location (${geohashLat}, ${geohashLng})`);
           throw new InvalidProviderLocationError(
             `${provider.name} provider does not support the provided location.`
           );
         }
 
         // Attempt to get weather data from the provider
-        const weather = await provider.getWeather(lat, lng);
+        const weather = await provider.getWeather(geohashLat, geohashLng);
 
         // Store the retrieved weather data in cache
         await this.cache.set(locationGeohash, JSON.stringify(weather));