kstd: fix push/emplace_back bug in vector

2 files changed, 174 insertions, 0 deletions

diff --git a/libs/kstd/include/kstd/vector b/libs/kstd/include/kstd/vector
index b2cce0b..1242489 100644
--- a/libs/kstd/include/kstd/vector
+++ b/libs/kstd/include/kstd/vector
@@ -594,12 +594,14 @@ namespace kstd
       {
         auto new_capacity = m_capacity == 0 ? 1 : m_capacity * 2;
         auto new_data = allocate_n(new_capacity);
+        auto old_size = size();
         std::allocator_traits<allocator_type>::construct(m_allocator, new_data + m_size, value);
         uninitialized_move_with_allocator(begin(), new_data, size());
         destroy_n(begin(), size());
         deallocate();
         m_data = new_data;
         m_capacity = new_capacity;
+        m_size = old_size;
       }
       else
       {
@@ -615,12 +617,14 @@ namespace kstd
       {
         auto new_capacity = m_capacity == 0 ? 1 : m_capacity * 2;
         auto new_data = allocate_n(new_capacity);
+        auto old_size = size();
         std::allocator_traits<allocator_type>::construct(m_allocator, new_data + m_size, std::move(value));
         uninitialized_move_with_allocator(begin(), new_data, size());
         destroy_n(begin(), size());
         deallocate();
         m_data = new_data;
         m_capacity = new_capacity;
+        m_size = old_size;
       }
       else
       {
@@ -637,12 +641,14 @@ namespace kstd
       {
         auto new_capacity = m_capacity == 0 ? 1 : m_capacity * 2;
         auto new_data = allocate_n(new_capacity);
+        auto old_size = size();
         std::allocator_traits<allocator_type>::construct(m_allocator, new_data + m_size, std::forward<Args>(args)...);
         uninitialized_move_with_allocator(begin(), new_data, size());
         destroy_n(begin(), size());
         deallocate();
         m_data = new_data;
         m_capacity = new_capacity;
+        m_size = old_size;
       }
       else
       {
diff --git a/libs/kstd/tests/src/vector.cpp b/libs/kstd/tests/src/vector.cpp
index cb1b182..2440247 100644
--- a/libs/kstd/tests/src/vector.cpp
+++ b/libs/kstd/tests/src/vector.cpp
@@ -392,4 +392,172 @@ SCENARIO("Vector capacity management", "[vector]")
       }
     }
   }
+}
+
+SCENARIO("Vector modifiers", "[vector]")
+{
+  GIVEN("An empty vector")
+  {
+    kstd::vector<int> v;
+
+    WHEN("push_back is called with a value")
+    {
+      v.push_back(10);
+
+      THEN("the element is added and the size and capacity increase")
+      {
+        REQUIRE(v.size() == 1);
+        REQUIRE(v.capacity() >= 1);
+        REQUIRE(v.back() == 10);
+      }
+    }
+
+    WHEN("emplace_back is called with constructor arguments")
+    {
+      v.emplace_back(20);
+
+      THEN("the element is added and the size and capacity increase")
+      {
+        REQUIRE(v.size() == 1);
+        REQUIRE(v.capacity() >= 1);
+        REQUIRE(v.back() == 20);
+      }
+    }
+  }
+
+  GIVEN("A populated vector")
+  {
+    kstd::vector<int> v = {10, 20, 30};
+    auto initial_capacity = v.capacity();
+
+    WHEN("push_back is called")
+    {
+      v.push_back(40);
+
+      THEN("the element is added and the size and capacity increase")
+      {
+        REQUIRE(v.size() == 4);
+        REQUIRE(v.capacity() >= initial_capacity);
+        REQUIRE(v[0] == 10);
+        REQUIRE(v[1] == 20);
+        REQUIRE(v[2] == 30);
+        REQUIRE(v[3] == 40);
+      }
+    }
+
+    WHEN("emplace_back is called with constructor arguments")
+    {
+      v.emplace_back(40);
+
+      THEN("the element is added and the size and capacity increase")
+      {
+        REQUIRE(v.size() == 4);
+        REQUIRE(v.capacity() >= initial_capacity);
+        REQUIRE(v[0] == 10);
+        REQUIRE(v[1] == 20);
+        REQUIRE(v[2] == 30);
+        REQUIRE(v[3] == 40);
+      }
+    }
+
+    WHEN("pop_back is called")
+    {
+      v.pop_back();
+
+      THEN("the last element is removed and the size decreases")
+      {
+        REQUIRE(v.size() == 2);
+        REQUIRE(v.capacity() == initial_capacity);
+        REQUIRE(v[0] == 10);
+        REQUIRE(v[1] == 20);
+      }
+    }
+
+    WHEN("clear is called")
+    {
+      v.clear();
+
+      THEN("the vector is empty")
+      {
+        REQUIRE(v.empty());
+        REQUIRE(v.size() == 0);
+        REQUIRE(v.capacity() == initial_capacity);
+      }
+    }
+  }
+}
+
+SCENARIO("Vector comparison", "[vector]")
+{
+  GIVEN("Two identical vectors")
+  {
+    kstd::vector<int> v1 = {1, 2, 3};
+    kstd::vector<int> v2 = {1, 2, 3};
+
+    WHEN("comparing for equality")
+    {
+      THEN("the vectors are equal")
+      {
+        REQUIRE(v1 == v2);
+      }
+
+      THEN("the vectors and not not-equal")
+      {
+        REQUIRE_FALSE(v1 != v2);
+      }
+    }
+
+    WHEN("comparing using the spaceship operator")
+    {
+      THEN("the vectors are equivalent")
+      {
+        REQUIRE((v1 <=> v2) == 0);
+        REQUIRE(v1 <= v2);
+        REQUIRE(v1 >= v2);
+      }
+    }
+  }
+
+  GIVEN("Two vectors of different sizes")
+  {
+    kstd::vector<int> v1 = {1, 2, 3};
+    kstd::vector<int> v2 = {1, 2, 3, 4};
+
+    WHEN("comparing for equality")
+    {
+      THEN("the vectors are not equal")
+      {
+        REQUIRE_FALSE(v1 == v2);
+      }
+
+      THEN("the vectors are not-equal")
+      {
+        REQUIRE(v1 != v2);
+      }
+    }
+
+    WHEN("comparing for ordering")
+    {
+      THEN("the shorter vector evaluates as less than the longer vector")
+      {
+        REQUIRE(v1 < v2);
+        REQUIRE(v2 > v1);
+      }
+    }
+  }
+
+  GIVEN("Two vectors of the same size but different elements")
+  {
+    kstd::vector<int> v1 = {1, 2, 3};
+    kstd::vector<int> v2 = {1, 2, 4};
+
+    WHEN("comparing for ordering")
+    {
+      THEN("they are ordered lexicographically")
+      {
+        REQUIRE(v1 < v2);
+        REQUIRE(v2 > v1);
+      }
+    }
+  }
 }
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