From 2c46e4765813bb46998619c2458db89f2c9ef903 Mon Sep 17 00:00:00 2001
From: "Brock A. Martin" <bamartin125@gmail.com>
Date: Tue, 20 Oct 2020 10:41:56 -0500
Subject: [PATCH] Add tests for update order consistency

---
 tests/test_coverage_sortedkeylist_modulo.py | 13 +++++++++++++
 tests/test_coverage_sortedkeylist_negate.py | 14 +++++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/tests/test_coverage_sortedkeylist_modulo.py b/tests/test_coverage_sortedkeylist_modulo.py
index 1916054f..fc612a07 100644
--- a/tests/test_coverage_sortedkeylist_modulo.py
+++ b/tests/test_coverage_sortedkeylist_modulo.py
@@ -5,6 +5,7 @@
 import random
 from .context import sortedcontainers
 from sortedcontainers import SortedList, SortedKeyList
+from itertools import chain, repeat
 import pytest
 
 if hexversion < 0x03000000:
@@ -107,6 +108,18 @@ def test_update():
     assert len(slt) == 11000
     slt._check()
 
+def test_update_order_consistency():
+    slt = SortedKeyList(key=lambda x: x[0])
+
+    it1 = list(zip(repeat(0), range(4)))
+    it2 = list(zip(repeat(0), range(5)))
+
+    slt.update(it1)
+    slt.update(it2)
+    slt._check()
+
+    assert all(tup[0] == tup[1] for tup in zip(slt, chain(it1, it2)))
+
 def test_contains():
     slt = SortedKeyList(key=modulo)
     slt._reset(7)
diff --git a/tests/test_coverage_sortedkeylist_negate.py b/tests/test_coverage_sortedkeylist_negate.py
index 6c0287f8..2bacfd7f 100644
--- a/tests/test_coverage_sortedkeylist_negate.py
+++ b/tests/test_coverage_sortedkeylist_negate.py
@@ -5,7 +5,7 @@
 import random
 from .context import sortedcontainers
 from sortedcontainers import SortedKeyList, SortedListWithKey
-from itertools import chain
+from itertools import chain, repeat
 import pytest
 
 if hexversion < 0x03000000:
@@ -84,6 +84,18 @@ def test_update():
     values = sorted((val for val in chain(range(100), range(1000), range(10000))), key=negate)
     assert all(tup[0] == tup[1] for tup in zip(slt, values))
 
+def test_update_order_consistency():
+    slt = SortedKeyList(key=lambda x: x[0])
+
+    it1 = list(zip(repeat(0), range(4)))
+    it2 = list(zip(repeat(0), range(5)))
+
+    slt.update(it1)
+    slt.update(it2)
+    slt._check()
+
+    assert all(tup[0] == tup[1] for tup in zip(slt, chain(it1, it2)))
+
 def test_contains():
     slt = SortedKeyList(key=negate)
     assert 0 not in slt