chore: fix watch clearing issues

Author: michalchudziak

ios/RNCGeolocation.mm

@@ -309,6 +309,10 @@ - (void)enableBackgroundLocationUpdates
 RCT_REMAP_METHOD(startObserving, startObserving:(RNCGeolocationOptions)options)
 {
   checkLocationConfig();
+    
+  if (_observingLocation) {
+    [self stopObserving];
+  }
 
   // Select best options
   _observerOptions = options;
@@ -376,6 +380,12 @@ - (void)enableBackgroundLocationUpdates
     successBlock(@[_lastLocationEvent]);
     return;
   }
+    
+  BOOL didPause = NO;
+  if (_observingLocation) {
+    [self stopObserving];
+    didPause = YES;
+  }
 
   // Create request
   RNCGeolocationRequest *request = [RNCGeolocationRequest new];
@@ -400,6 +410,10 @@ - (void)enableBackgroundLocationUpdates
   [self beginLocationUpdatesWithDesiredAccuracy:accuracy
                                  distanceFilter:options.distanceFilter
                           useSignificantChanges:options.useSignificantChanges];
+
+  if (didPause) {
+    [self startObserving];
+  }
 }
 
 #pragma mark - CLLocationManagerDelegate

js/implementation.native.ts

@@ -23,10 +23,9 @@ import type {
 
 const { RNCGeolocation, GeolocationEventEmitter } = GeolocationNativeInterface;
 
-let subscriptions: (
-  | [EmitterSubscription, EmitterSubscription | null]
-  | undefined
-)[] = [];
+let subscriptions: {
+  [key: number]: [EmitterSubscription, EmitterSubscription | null];
+} = {};
 let updatesEnabled = false;
 
 /**
@@ -100,13 +99,13 @@ export function watchPosition(
     RNCGeolocation.startObserving(options);
     updatesEnabled = true;
   }
-  const watchID = subscriptions.length;
-  subscriptions.push([
+  const watchID = Object.keys(subscriptions).length + 1000;
+  subscriptions[watchID] = [
     GeolocationEventEmitter.addListener('geolocationDidChange', success),
     error
       ? GeolocationEventEmitter.addListener('geolocationError', error)
       : null,
-  ]);
+  ];
   return watchID;
 }
 
@@ -117,6 +116,7 @@ export function watchPosition(
  */
 export function clearWatch(watchID: number) {
   const sub = subscriptions[watchID];
+  console.log('clear watch', watchID, sub);
   if (!sub) {
     // Silently exit when the watchID is invalid or already cleared
     // This is consistent with timers
@@ -127,13 +127,9 @@ export function clearWatch(watchID: number) {
   // array element refinements not yet enabled in Flow
   const sub1 = sub[1];
   sub1 && sub1.remove();
-  subscriptions[watchID] = undefined;
-  let noWatchers = true;
-  for (let ii = 0; ii < subscriptions.length; ii++) {
-    if (subscriptions[ii]) {
-      noWatchers = false; // still valid subscriptions
-    }
-  }
+
+  delete subscriptions[watchID];
+  let noWatchers = Object.keys(subscriptions).length === 0;
   if (noWatchers) {
     stopObserving();
   }
@@ -146,18 +142,14 @@ export function clearWatch(watchID: number) {
  */
 export function stopObserving() {
   if (updatesEnabled) {
+    console.log('stopping observing')
     RNCGeolocation.stopObserving();
     updatesEnabled = false;
-    for (let ii = 0; ii < subscriptions.length; ii++) {
-      const sub = subscriptions[ii];
-      if (sub) {
-        warning(false, 'Called stopObserving with existing subscriptions.');
-        sub[0].remove();
-        // array element refinements not yet enabled in Flow
-        const sub1 = sub[1];
-        sub1 && sub1.remove();
-      }
-    }
-    subscriptions = [];
+    Object.values(subscriptions).forEach(([sub, sub1]) => {
+      warning(false, 'Called stopObserving with existing subscriptions.');
+      sub.remove();
+      sub1 && sub1.remove();
+    });
+    subscriptions = {};
   }
 }