test: Add sendall test for min-fee setting

Author: aureleoules

test/functional/wallet_sendall.py

@@ -284,6 +284,12 @@ def sendall_fails_on_high_fee(self):
                 recipients=[self.remainder_target],
                 fee_rate=100000)
 
+    @cleanup
+    def sendall_fails_on_low_fee(self):
+        self.log.info("Test sendall fails if the transaction fee is lower than the minimum fee rate setting")
+        assert_raises_rpc_error(-8, "Fee rate (0.999 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)",
+        self.wallet.sendall, recipients=[self.recipient], fee_rate=0.999)
+
     @cleanup
     def sendall_watchonly_specific_inputs(self):
         self.log.info("Test sendall with a subset of UTXO pool in a watchonly wallet")
@@ -376,6 +382,9 @@ def run_test(self):
         # Sendall fails when providing a fee that is too high
         self.sendall_fails_on_high_fee()
 
+        # Sendall fails when fee rate is lower than minimum
+        self.sendall_fails_on_low_fee()
+
         # Sendall succeeds with watchonly wallets spending specific UTXOs
         self.sendall_watchonly_specific_inputs()