test: refactor functional tests to use restart_node

test/functional/wallet_abandonconflict.py

@@ -95,8 +95,7 @@ class AbandonConflictTest(BitcoinTestFramework):
 
         # Restart the node with a higher min relay fee so the parent tx is no longer in mempool
         # TODO: redo with eviction
-        self.stop_node(0)
-        self.start_node(0, extra_args=["-minrelaytxfee=0.0001"])
+        self.restart_node(0, extra_args=["-minrelaytxfee=0.0001"])
         assert self.nodes[0].getmempoolinfo()['loaded']
 
         # Verify txs no longer in either node's mempool
@@ -123,8 +122,7 @@ class AbandonConflictTest(BitcoinTestFramework):
         balance = newbalance
 
         # Verify that even with a low min relay fee, the tx is not reaccepted from wallet on startup once abandoned
-        self.stop_node(0)
-        self.start_node(0, extra_args=["-minrelaytxfee=0.00001"])
+        self.restart_node(0, extra_args=["-minrelaytxfee=0.00001"])
         assert self.nodes[0].getmempoolinfo()['loaded']
 
         assert_equal(len(self.nodes[0].getrawmempool()), 0)
@@ -145,8 +143,7 @@ class AbandonConflictTest(BitcoinTestFramework):
         balance = newbalance
 
         # Remove using high relay fee again
-        self.stop_node(0)
-        self.start_node(0, extra_args=["-minrelaytxfee=0.0001"])
+        self.restart_node(0, extra_args=["-minrelaytxfee=0.0001"])
         assert self.nodes[0].getmempoolinfo()['loaded']
         assert_equal(len(self.nodes[0].getrawmempool()), 0)
         newbalance = self.nodes[0].getbalance()