pytest: test pay ordering.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_pay.py

@@ -3498,6 +3498,20 @@ def test_listpays_ongoing_attempt(node_factory, bitcoind, executor):
     l1.rpc.listpays()
 
 
+def test_listsendpays_and_listpays_order(node_factory):
+    """listsendpays should be in increasing id order, listpays in created_at"""
+    l1, l2 = node_factory.line_graph(2)
+    for i in range(5):
+        inv = l2.rpc.invoice(1000 - i, "test {}".format(i), "test")['bolt11']
+        l1.rpc.pay(inv)
+
+    ids = [p['id'] for p in l1.rpc.listsendpays()['payments']]
+    assert ids == sorted(ids)
+
+    created_at = [p['created_at'] for p in l1.rpc.listpays()['pays']]
+    assert created_at == sorted(created_at)
+
+
 @pytest.mark.developer("needs use_shadow")
 def test_mpp_waitblockheight_routehint_conflict(node_factory, bitcoind, executor):
     '''