AK: Define operator== for HashMap

Author: kalenikaliaksandr

AK/HashMap.h

@@ -322,6 +322,27 @@ class HashMap {
         return hash_map_clone;
     }
 
+    bool operator==(HashMap const& other) const
+    {
+        if (size() != other.size())
+            return false;
+        if (is_empty())
+            return true;
+        for (auto const& [key, value] : *this) {
+            auto it = other.find(key);
+            if (it == other.end())
+                return false;
+            if (!ValueTraits::equals(value, it->value))
+                return false;
+        }
+        return true;
+    }
+
+    bool operator!=(HashMap const& other) const
+    {
+        return !(*this == other);
+    }
+
 private:
     HashTableType m_table;
 };

Tests/AK/TestHashMap.cpp

@@ -353,3 +353,18 @@ TEST_CASE(update)
     second.update(first);
     EXPECT_EQ(4u, second.size());
 }
+
+TEST_CASE(compare)
+{
+    HashMap<int, int> first;
+    HashMap<int, int> second;
+
+    EXPECT_EQ(first, second);
+
+    first.set(1, 10);
+    second.set(1, 10);
+    EXPECT_EQ(first, second);
+
+    first.set(2, 20);
+    EXPECT_NE(second, first);
+}