Test we adhere to max_total_routing_fee_msat

Author: tnull

lightning/src/routing/router.rs

@@ -5100,9 +5100,21 @@ mod tests {
 			} else { panic!(); }
 		}
 
+		{
+			// Attempt to route while setting max_total_routing_fee_msat to 149_999 results in a failure.
+			let fail_payment_params = payment_params.clone().with_max_total_routing_fee_msat(149_999);
+			if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
+				&our_id, &fail_payment_params, &network_graph.read_only(), None, 200_000,
+				Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
+					assert_eq!(err, "Failed to find a sufficient route to the given destination");
+			} else { panic!(); }
+		}
+
 		{
 			// Now, attempt to route 200 sats (exact amount we can route).
-			let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+			let payment_params = payment_params.clone().with_max_total_routing_fee_msat(150_000);
+			let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
+				200_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
 			assert_eq!(route.paths.len(), 2);
 
 			let mut total_amount_paid_msat = 0;