fix: format undefined fields

src/lib/get-data.mjs

@@ -1,5 +1,11 @@
 import fetch from './fetch.mjs';
 
+const formatNumber = str => str && Number(`${str}`.replace(/[^0-9.-]/, ''));
+const formatString = str => {
+  if (typeof str !== 'string') return str;
+  return str && str.length && str !== 'undefined' ? str.trim() : 'N/A';
+};
+
 export async function getOpenskyData() {
   const positionSourceMap = ['ADS-B', 'ASTERIX', 'MLAT'];
   const res = await fetch.get(`https://opensky-network.org/api/states/all`);
@@ -25,15 +31,14 @@ export async function getOpenskyData() {
 
 export async function getAdbsExchangeData({ lat, lon, radius }) {
   const positionSourceMap = ['Unknown', 'Mode-S', 'ADS-B', 'ADS-B', 'ADS-B', 'ADS-B'];
-  const formatNumber = str => str && Number(`${str}`.replace(/[^0-9.-]/, ''));
 
   const res = await fetch.get(
     `http://public-api.adsbexchange.com/VirtualRadar/AircraftList.json?lat=${lat}&lng=${lon}&fDstL=0&fDstU=${radius}`
   );
 
   return res.data.acList.map(rec => ({
-    transponder: `${rec.Icao}`.toLowerCase(),
-    callsign: `${rec.Call}`.trim(),
+    transponder: formatString(`${rec.Icao}`.toLowerCase()),
+    callsign: formatString(rec.Call),
     origin_country: rec.Cou,
     time_position: new Date(rec.PosTime),
     last_contact: new Date(rec.PosTime),
@@ -48,10 +53,10 @@ export async function getAdbsExchangeData({ lat, lon, radius }) {
     squawk: rec.Sqk,
     spi: false,
     position_source: positionSourceMap[rec.Trt],
-    operator: rec.Op,
-    aircraft: rec.Mdl,
-    aircraft_manufacturer: rec.Man,
-    from: rec.From,
-    to: rec.To,
+    operator: formatString(rec.Op),
+    aircraft: formatString(rec.Mdl),
+    aircraft_manufacturer: formatString(rec.Man),
+    from: formatString(rec.From),
+    to: formatString(rec.To),
   }));
 }