commands: add cmd wait_for_sync

electrum/commands.py

@@ -1412,6 +1412,14 @@ class Commands(Logger):
         """ return wallet synchronization status """
         return wallet.is_up_to_date()
 
+    @command('wn')
+    async def wait_for_sync(self, wallet: Abstract_Wallet = None):
+        """Block until the wallet synchronization finishes."""
+        while True:
+            if wallet.is_up_to_date():
+                return True
+            await wallet.up_to_date_changed_event.wait()
+
     @command('n')
     async def getfeerate(self):
         """

electrum/wallet.py

@@ -438,6 +438,7 @@ class Abstract_Wallet(ABC, Logger, EventListener):
         # true when synchronized. this is stricter than adb.is_up_to_date():
         # to-be-generated (HD) addresses are also considered here (gap-limit-roll-forward)
         self._up_to_date = False
+        self.up_to_date_changed_event = asyncio.Event()
 
         self.test_addresses_sanity()
         if self.storage and self.has_storage_encryption():
@@ -588,6 +589,8 @@ class Abstract_Wallet(ABC, Logger, EventListener):
         if status_changed or up_to_date:  # suppress False->False transition, as it is spammy
             util.trigger_callback('wallet_updated', self)
             util.trigger_callback('status')
+            self.up_to_date_changed_event.set()
+            self.up_to_date_changed_event.clear()
         if status_changed:
             self.logger.info(f'set_up_to_date: {up_to_date}')
 

tests/regtest/regtest.sh

@@ -114,7 +114,7 @@ if [[ $1 == "start" ]]; then
     agent="./run_electrum --regtest -D /tmp/$2"
     $agent daemon -d
     $agent load_wallet
-    sleep 1 # give time to synchronize
+    $agent wait_for_sync
 fi
 
 if [[ $1 == "stop" ]]; then
@@ -170,6 +170,7 @@ if [[ $1 == "backup" ]]; then
     $alice daemon -d
     $alice load_wallet
     $alice import_channel_backup $backup
+    $alice wait_for_sync
     echo "request force close $channel1"
     $alice request_force_close $channel1
     echo "request force close $channel2"