Initial commit of mtgonline project

C++/tests/clamped_arithmetic_test.cpp

@@ -0,0 +1,44 @@
+/** @file clamped_arithmetic_test.cpp
+ *  @brief Tests for shared helpers in clamped_arithmetic.h.
+ *  @ingroup Tests
+ */
+
+#include <gtest/gtest.h>
+#include <libcockatrice/utility/clamped_arithmetic.h>
+#include <limits>
+
+TEST(AddClamped, AddsWithinBounds)
+{
+    EXPECT_EQ(addClamped(5, 3, 0, 100), 8);
+    EXPECT_EQ(addClamped(10, -3, 0, 100), 7);
+}
+
+TEST(AddClamped, ClampsToUpperAndLowerBound)
+{
+    EXPECT_EQ(addClamped(99, 5, 0, 100), 100);  // saturates at max
+    EXPECT_EQ(addClamped(2, -10, 0, 100), 0);   // saturates at min
+    EXPECT_EQ(addClamped(999, 1, 0, 999), 999); // crossing the counter cap holds at the bound
+}
+
+TEST(AddClamped, IntOverflowDoesNotWrap)
+{
+    // The 64-bit intermediate must prevent signed-int overflow UB.
+    constexpr int intMax = std::numeric_limits<int>::max();
+    constexpr int intMin = std::numeric_limits<int>::min();
+    EXPECT_EQ(addClamped(intMax, 1, intMin, intMax), intMax);
+    EXPECT_EQ(addClamped(intMax, intMax, intMin, intMax), intMax);
+}
+
+TEST(AddClamped, IntUnderflowDoesNotWrap)
+{
+    constexpr int intMax = std::numeric_limits<int>::max();
+    constexpr int intMin = std::numeric_limits<int>::min();
+    EXPECT_EQ(addClamped(intMin, -1, intMin, intMax), intMin);
+    EXPECT_EQ(addClamped(intMin, intMin, intMin, intMax), intMin);
+}
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}