1 files changed, 61 insertions, 0 deletions
diff --git a/Tests/AK/TestHashFunctions.cpp b/Tests/AK/TestHashFunctions.cpp
new file mode 100644
index 0000000000..fa8eafae9e
--- /dev/null
+++ b/Tests/AK/TestHashFunctions.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibTest/TestCase.h>
+
+#include <AK/HashFunctions.h>
+#include <AK/Types.h>
+
+TEST_CASE(int_hash)
+{
+    static_assert(int_hash(42) == 3564735745u);
+    static_assert(int_hash(0) == 1177991625u);
+}
+
+TEST_CASE(double_hash)
+{
+    static_assert(double_hash(42) == 524450u);
+    static_assert(double_hash(0) == 12384u);
+}
+
+TEST_CASE(pair_int_hash)
+{
+    static_assert(pair_int_hash(42, 17) == 339337046u);
+    static_assert(pair_int_hash(0, 0) == 954888656u);
+}
+
+TEST_CASE(u64_hash)
+{
+    static_assert(u64_hash(42) == 2824066580u);
+    static_assert(u64_hash(0) == 954888656u);
+}
+
+TEST_CASE(ptr_hash)
+{
+    // These tests are not static_asserts because the values are
+    // different and the goal is to bind the behavior.
+    if constexpr (sizeof(FlatPtr) == 8) {
+        EXPECT_EQ(ptr_hash(FlatPtr(42)), 2824066580u);
+        EXPECT_EQ(ptr_hash(FlatPtr(0)), 954888656u);
+
+        EXPECT_EQ(ptr_hash(reinterpret_cast<const void*>(42)), 2824066580u);
+        EXPECT_EQ(ptr_hash(reinterpret_cast<const void*>(0)), 954888656u);
+    } else {
+        EXPECT_EQ(ptr_hash(FlatPtr(42)), 3564735745u);
+        EXPECT_EQ(ptr_hash(FlatPtr(0)), 1177991625u);
+
+        EXPECT_EQ(ptr_hash(reinterpret_cast<const void*>(42)), 3564735745u);
+        EXPECT_EQ(ptr_hash(reinterpret_cast<const void*>(0)), 1177991625u);
+    }
+}
+
+TEST_CASE(constexpr_ptr_hash)
+{
+    // This test does not check the result because the goal is just to
+    // ensure the function can be executed in a constexpr context. The
+    // "ptr_hash" test binds the result.
+    static_assert(ptr_hash(FlatPtr(42)));
+}