fix: added config validation

src/Base.ts

@@ -31,9 +31,23 @@ export class BaseCalculator {
     this._prayerConfig = config
     const { date, latitude, longitude, method, ...paramsOptions } = this._prayerConfig
 
+    if (date.toString() === 'Invalid Date') {
+      throw new Error('You must provide a valid date')
+    }
+
+    if (latitude < -90 || latitude > 90) {
+      throw new Error('Latitude must be between -90 and 90')
+    } else if (longitude < -180 || longitude > 180) {
+      throw new Error('Longitude must be between -180 and 180')
+    } else if (latitude === undefined && longitude === undefined) {
+      throw new Error('You must provide a valid latitude and longitude')
+    }
     // create a coordinate object
     const coordinates = new Coordinates(latitude, longitude)
 
+    if (method === undefined) {
+      this._logger.warn('No calculation method provided, using Umm Al Qura as default')
+    }
     // create calculation params based on the method name
     const calculationParams = this._useMethod(method)