Handle `heatmapDensity` expression evaluation parameter in node bindings

4 files changed, 17 insertions, 11 deletions

diff --git a/include/mbgl/style/expression/expression.hpp b/include/mbgl/style/expression/expression.hpp
index b57af0906b..6c0f11a675 100644
--- a/include/mbgl/style/expression/expression.hpp
+++ b/include/mbgl/style/expression/expression.hpp
@@ -27,6 +27,9 @@ struct EvaluationParameters {
     EvaluationParameters(float zoom_, GeometryTileFeature const * feature_) :
         zoom(zoom_), feature(feature_)
     {}
+    EvaluationParameters(optional<float> zoom_, GeometryTileFeature const * feature_, optional<double> heatmapDensity_) :
+        zoom(std::move(zoom_)), feature(feature_), heatmapDensity(std::move(heatmapDensity_))
+    {}
     
     optional<float> zoom;
     GeometryTileFeature const * feature;
@@ -114,9 +117,9 @@ public:
 
     bool isFeatureConstant() const;
     bool isZoomConstant() const;
-    EvaluationResult evaluate(float z, const Feature& feature) const;
     type::Type getType() const { return type; };
     
+    EvaluationResult evaluate(optional<float> zoom, const Feature& feature, optional<double> heatmapDensity) const;
 private:
     type::Type type;
 };
diff --git a/platform/node/src/node_expression.cpp b/platform/node/src/node_expression.cpp
index e75478320c..38a444f203 100644
--- a/platform/node/src/node_expression.cpp
+++ b/platform/node/src/node_expression.cpp
@@ -168,11 +168,17 @@ void NodeExpression::Evaluate(const Nan::FunctionCallbackInfo<v8::Value>& info)
     NodeExpression* nodeExpr = ObjectWrap::Unwrap<NodeExpression>(info.Holder());
     const std::unique_ptr<Expression>& expression = nodeExpr->expression;
 
-    if (info.Length() < 2) {
-        return Nan::ThrowTypeError("Requires arguments zoom and feature arguments.");
+    if (info.Length() < 2 || !info[0]->IsObject()) {
+        return Nan::ThrowTypeError("Requires globals and feature arguments.");
     }
 
-    float zoom = info[0]->NumberValue();
+    mbgl::optional<float> zoom;
+    v8::Local<v8::Value> v8zoom = Nan::Get(info[0]->ToObject(), Nan::New("zoom").ToLocalChecked()).ToLocalChecked();
+    if (v8zoom->IsNumber()) zoom = v8zoom->NumberValue();
+
+    mbgl::optional<double> heatmapDensity;
+    v8::Local<v8::Value> v8heatmapDensity = Nan::Get(info[0]->ToObject(), Nan::New("heatmapDensity").ToLocalChecked()).ToLocalChecked();
+    if (v8heatmapDensity->IsNumber()) heatmapDensity = v8heatmapDensity->NumberValue();
 
     Nan::JSON NanJSON;
     conversion::Error conversionError;
@@ -184,7 +190,7 @@ void NodeExpression::Evaluate(const Nan::FunctionCallbackInfo<v8::Value>& info)
 
     try {
         mapbox::geojson::feature feature = geoJSON->get<mapbox::geojson::feature>();
-        auto result = expression->evaluate(zoom, feature);
+        auto result = expression->evaluate(zoom, feature, heatmapDensity);
         if (result) {
             info.GetReturnValue().Set(toJS(*result));
         } else {
diff --git a/platform/node/test/expression.test.js b/platform/node/test/expression.test.js
index b54dd342e5..6ffea28d40 100644
--- a/platform/node/test/expression.test.js
+++ b/platform/node/test/expression.test.js
@@ -47,16 +47,13 @@ suite.run('native', {tests: tests}, (fixture) => {
         const evaluate = fixture.inputs || [];
         const evaluateResults = [];
         for (const input of evaluate) {
-            const zoom = typeof input[0].zoom === 'number' ?
-                input[0].zoom : -1;
-
             const feature = Object.assign({
                 type: 'Feature',
                 properties: {},
                 geometry: { type: 'Point', coordinates: [0, 0] }
             }, input[1])
 
-            const output = expression.evaluate(zoom, feature);
+            const output = expression.evaluate(input[0], feature);
             evaluateResults.push(output);
         }
 
diff --git a/src/mbgl/style/function/expression.cpp b/src/mbgl/style/function/expression.cpp
index ccbc59a5f0..e9cc0b0e1c 100644
--- a/src/mbgl/style/function/expression.cpp
+++ b/src/mbgl/style/function/expression.cpp
@@ -59,9 +59,9 @@ bool Expression::isZoomConstant() const {
     return zoomConstant;
 }
 
-EvaluationResult Expression::evaluate(float z, const Feature& feature) const {
+EvaluationResult Expression::evaluate(optional<float> zoom, const Feature& feature, optional<double> heatmapDensity) const {
     GeoJSONFeature f(feature);
-    return this->evaluate(EvaluationParameters(z, &f));
+    return this->evaluate(EvaluationParameters(zoom, &f, heatmapDensity));
 }
 
 } // namespace expression