From 8dc24d0256314265053a9e4b93d0542d14f8d8a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?kleines=20Filmr=C3=B6llchen?= <filmroellchen@serenityos.org>
Date: Tue, 8 Mar 2022 00:43:21 +0100
Subject: [PATCH] Tests: Test non-trivial re-hashing in HashTable

This caused a system-wide crash because of a previous bug relating to
non-trivial types in HashTable. Therefore, check that such types
actually work under various workloads.
---
 Tests/AK/TestHashTable.cpp | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/Tests/AK/TestHashTable.cpp b/Tests/AK/TestHashTable.cpp
index 2e3ddc5582..4f5aa422b5 100644
--- a/Tests/AK/TestHashTable.cpp
+++ b/Tests/AK/TestHashTable.cpp
@@ -7,6 +7,7 @@
 #include <LibTest/TestCase.h>
 
 #include <AK/HashTable.h>
+#include <AK/NonnullOwnPtr.h>
 #include <AK/String.h>
 
 TEST_CASE(construct)
@@ -235,6 +236,26 @@ TEST_CASE(capacity_leak)
     EXPECT(table.capacity() < 100u);
 }
 
+TEST_CASE(non_trivial_type_table)
+{
+    HashTable<NonnullOwnPtr<int>> table;
+
+    table.set(make<int>(3));
+    table.set(make<int>(11));
+
+    for (int i = 0; i < 1'000; ++i) {
+        table.set(make<int>(-i));
+    }
+    for (int i = 0; i < 10'000; ++i) {
+        table.set(make<int>(i));
+        table.remove(make<int>(i));
+    }
+
+    EXPECT_EQ(table.remove_all_matching([&](auto&) { return true; }), true);
+    EXPECT(table.is_empty());
+    EXPECT_EQ(table.remove_all_matching([&](auto&) { return true; }), false);
+}
+
 // Inserting and removing a bunch of elements will "thrash" the table, leading to a lot of "deleted" markers.
 BENCHMARK_CASE(benchmark_thrashing)
 {