Add unit test for isExpression

3 files changed, 49 insertions, 14 deletions

diff --git a/cmake/test-files.cmake b/cmake/test-files.cmake
index 67c3adcb3d..5df5fb38d1 100644
--- a/cmake/test-files.cmake
+++ b/cmake/test-files.cmake
@@ -88,6 +88,7 @@ set(MBGL_TEST_FILES
     test/style/conversion/stringify.test.cpp
 
     # style/expression
+    test/style/expression/is_expression.test.cpp
     test/style/expression/util.test.cpp
 
     # style
diff --git a/src/mbgl/style/expression/is_expression.cpp b/src/mbgl/style/expression/is_expression.cpp
index 1b70c7a096..c7f6599d94 100644
--- a/src/mbgl/style/expression/is_expression.cpp
+++ b/src/mbgl/style/expression/is_expression.cpp
@@ -9,24 +9,25 @@ bool isExpression(const conversion::Convertible& value) {
     using namespace mbgl::style::conversion;
     
     static std::unordered_set<std::string> specialForms = {
-        "literal",
-        "match",
-        "curve",
-        "coalesce",
+        "all",
+        "any",
         "array",
-        "let",
-        "var",
         "at",
-        "string",
-        "number",
-        "color",
         "boolean",
-        "to-string",
-        "to-number",
-        "to-color",
+        "case",
+        "coalesce",
+        "color",
+        "curve",
+        "let",
+        "literal",
+        "match",
+        "number",
+        "string",
         "to-boolean",
-        "any",
-        "all"
+        "to-color",
+        "to-number",
+        "to-string",
+        "var",
     };
 
     if (!isArray(value) || arrayLength(value) == 0) return false;
diff --git a/test/style/expression/is_expression.test.cpp b/test/style/expression/is_expression.test.cpp
new file mode 100644
index 0000000000..bf76c3345e
--- /dev/null
+++ b/test/style/expression/is_expression.test.cpp
@@ -0,0 +1,33 @@
+#include <mbgl/test/util.hpp>
+#include <mbgl/util/io.hpp>
+#include <mbgl/style/conversion.hpp>
+#include <mbgl/util/rapidjson.hpp>
+#include <mbgl/style/rapidjson_conversion.hpp>
+#include <mbgl/style/expression/is_expression.hpp>
+
+#include <rapidjson/document.h>
+
+using namespace mbgl;
+using namespace mbgl::style;
+
+TEST(Expression, IsExpression) {
+    rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> spec;
+    spec.Parse<0>(util::read_file("mapbox-gl-js/src/style-spec/reference/v8.json").c_str());
+    ASSERT_FALSE(spec.HasParseError());
+    ASSERT_TRUE(spec.IsObject() &&
+                spec.HasMember("expression_name") &&
+                spec["expression_name"].IsObject() &&
+                spec["expression_name"].HasMember("values") &&
+                spec["expression_name"]["values"].IsObject());
+    
+    const auto& allExpressions = spec["expression_name"]["values"];
+    
+    for(auto& entry : allExpressions.GetObject()) {
+        const std::string name { entry.name.GetString(), entry.name.GetStringLength() };
+        JSDocument document;
+        document.Parse<0>(R"([")" + name + R"("])");
+
+        const JSValue* expression = &document;
+        EXPECT_TRUE(expression::isExpression(conversion::Convertible(expression))) << name;
+    }
+}