1 files changed, 139 insertions, 0 deletions
diff --git a/test/style/properties.test.cpp b/test/style/properties.test.cpp
new file mode 100644
index 0000000000..279fadb8c2
--- /dev/null
+++ b/test/style/properties.test.cpp
@@ -0,0 +1,139 @@
+#include <mbgl/test/util.hpp>
+
+#include <mbgl/style/properties.hpp>
+#include <mbgl/renderer/property_evaluator.hpp>
+#include <mbgl/renderer/data_driven_property_evaluator.hpp>
+
+using namespace mbgl;
+using namespace mbgl::style;
+using namespace std::literals::chrono_literals;
+
+float evaluate(Transitioning<PropertyValue<float>>& property, Duration delta = Duration::zero()) {
+    ZoomHistory zoomHistory;
+    zoomHistory.update(0, TimePoint::min() + delta);
+
+    PropertyEvaluationParameters parameters {
+        zoomHistory,
+        TimePoint::min() + delta,
+        Duration::zero()
+    };
+
+    PropertyEvaluator<float> evaluator {
+        parameters,
+        0.0f
+    };
+
+    return property.evaluate(evaluator, parameters.now);
+}
+
+PossiblyEvaluatedPropertyValue<float> evaluate(Transitioning<DataDrivenPropertyValue<float>>& property, Duration delta = Duration::zero()) {
+    ZoomHistory zoomHistory;
+    zoomHistory.update(0, TimePoint::min() + delta);
+
+    PropertyEvaluationParameters parameters {
+        zoomHistory,
+        TimePoint::min() + delta,
+        Duration::zero()
+    };
+    
+    DataDrivenPropertyEvaluator<float> evaluator {
+        parameters,
+        0.0f
+    };
+    
+    return property.evaluate(evaluator, parameters.now);
+}
+
+TEST(TransitioningPropertyValue, EvaluateDefaultValue) {
+    Transitioning<PropertyValue<float>> property;
+    ASSERT_EQ(0.0f, evaluate(property));
+}
+
+TEST(TransitioningPropertyValue, EvaluateUntransitionedConstant) {
+    Transitioning<PropertyValue<float>> property {
+        PropertyValue<float>(1.0f),
+        Transitioning<PropertyValue<float>>(),
+        TransitionOptions(),
+        TimePoint::min()
+    };
+
+    ASSERT_EQ(1.0f, evaluate(property));
+}
+
+TEST(TransitioningPropertyValue, EvaluateTransitionedConstantWithoutDelay) {
+    TransitionOptions transition;
+    transition.duration = { 1000ms };
+
+    Transitioning<PropertyValue<float>> t0 {
+        PropertyValue<float>(0.0f),
+        Transitioning<PropertyValue<float>>(),
+        TransitionOptions(),
+        TimePoint::min()
+    };
+
+    Transitioning<PropertyValue<float>> t1 {
+        PropertyValue<float>(1.0f),
+        t0,
+        transition,
+        TimePoint::min()
+    };
+
+    ASSERT_FLOAT_EQ(0.0f, evaluate(t1, 0ms));
+    ASSERT_FLOAT_EQ(0.823099f, evaluate(t1, 500ms));
+    ASSERT_FLOAT_EQ(1.0f, evaluate(t1, 1500ms));
+}
+
+TEST(TransitioningPropertyValue, EvaluateTransitionedConstantWithDelay) {
+    TransitionOptions transition;
+    transition.delay = { 1000ms };
+    transition.duration = { 1000ms };
+
+    Transitioning<PropertyValue<float>> t0 {
+        PropertyValue<float>(0.0f),
+        Transitioning<PropertyValue<float>>(),
+        TransitionOptions(),
+        TimePoint::min()
+    };
+
+    Transitioning<PropertyValue<float>> t1 {
+        PropertyValue<float>(1.0f),
+        t0,
+        transition,
+        TimePoint::min()
+    };
+
+    ASSERT_FLOAT_EQ(0.0f, evaluate(t1, 0ms));
+    ASSERT_FLOAT_EQ(0.0f, evaluate(t1, 500ms));
+    ASSERT_FLOAT_EQ(0.0f, evaluate(t1, 612ms));
+    ASSERT_FLOAT_EQ(0.823099f, evaluate(t1, 1500ms));
+    ASSERT_FLOAT_EQ(1.0f, evaluate(t1, 2500ms));
+}
+
+TEST(TransitioningDataDrivenPropertyValue, Evaluate) {
+    TransitionOptions transition;
+    transition.delay = { 1000ms };
+    transition.duration = { 1000ms };
+    
+    Transitioning<DataDrivenPropertyValue<float>> t0 {
+        DataDrivenPropertyValue<float>(0.0f),
+        Transitioning<DataDrivenPropertyValue<float>>(),
+        TransitionOptions(),
+        TimePoint::min()
+    };
+    
+    SourceFunction<float> sourceFunction = {
+        "property_name",
+        IdentityStops<float>()
+    };
+    
+    Transitioning<DataDrivenPropertyValue<float>> t1 {
+        DataDrivenPropertyValue<float>(sourceFunction),
+        t0,
+        transition,
+        TimePoint::min()
+    };
+    
+    ASSERT_TRUE(evaluate(t0, 0ms).isConstant());
+    ASSERT_FALSE(evaluate(t1, 0ms).isConstant()) <<
+        "A paint property transition to a data-driven evaluates immediately to the final value (see https://github.com/mapbox/mapbox-gl-native/issues/8237).";
+}