[core] Check for NaNs in mbgl::util::{min,max,clamp}

1 files changed, 42 insertions, 0 deletions

diff --git a/test/util/math.cpp b/test/util/math.cpp
new file mode 100644
index 0000000000..0074b43509
--- /dev/null
+++ b/test/util/math.cpp
@@ -0,0 +1,42 @@
+#include "../fixtures/util.hpp"
+
+#include <mbgl/util/constants.hpp>
+#include <mbgl/util/math.hpp>
+
+using namespace mbgl;
+
+TEST(Math, MinMaxFloatingPoint) {
+    double minimumValue = std::numeric_limits<double>::min();
+    double lowestValue = std::numeric_limits<double>::lowest();
+    double maximumValue = std::numeric_limits<double>::max();
+    double quietNAN = std::numeric_limits<double>::quiet_NaN();
+
+    ASSERT_DOUBLE_EQ(lowestValue, util::min(minimumValue, lowestValue));
+    ASSERT_DOUBLE_EQ(lowestValue, util::min(double(NAN), lowestValue));
+    ASSERT_DOUBLE_EQ(lowestValue, util::min(quietNAN, lowestValue));
+    ASSERT_DOUBLE_EQ(0., util::min(2., 1., 0.));
+
+    ASSERT_DOUBLE_EQ(maximumValue, util::max(double(NAN), maximumValue));
+    ASSERT_DOUBLE_EQ(maximumValue, util::max(quietNAN, maximumValue));
+    ASSERT_DOUBLE_EQ(10., util::max(8., 9., 10.));
+
+    ASSERT_DOUBLE_EQ(0., util::clamp(0., quietNAN, quietNAN));
+    ASSERT_DOUBLE_EQ(0., util::clamp(0., lowestValue, maximumValue));
+}
+
+TEST(Math, MinMaxIntegral) {
+    int32_t minimumValue = std::numeric_limits<int32_t>::min();
+    int32_t lowestValue = std::numeric_limits<int32_t>::lowest();
+    int32_t maximumValue = std::numeric_limits<int32_t>::max();
+    int32_t quietNAN = std::numeric_limits<int32_t>::quiet_NaN();
+
+    ASSERT_EQ(lowestValue, util::min(minimumValue, lowestValue));
+    ASSERT_EQ(lowestValue, util::min(quietNAN, lowestValue));
+    ASSERT_EQ(0, util::min(2, 1, 0));
+
+    ASSERT_EQ(maximumValue, util::max(quietNAN, maximumValue));
+    ASSERT_EQ(10, util::max(8, 9, 10));
+
+    ASSERT_EQ(0, util::clamp(0, quietNAN, quietNAN));
+    ASSERT_EQ(0, util::clamp(0, lowestValue, maximumValue));
+}