[core] Fix most identity function with default legacy expression tests

Add handling of default value to the conversion of legacy identity
functions. The color and enum tests still don't pass though.

1 files changed, 36 insertions, 14 deletions

diff --git a/src/mbgl/style/expression/dsl.cpp b/src/mbgl/style/expression/dsl.cpp
index b4fd8fa551..d1d8dea799 100644
--- a/src/mbgl/style/expression/dsl.cpp
+++ b/src/mbgl/style/expression/dsl.cpp
@@ -54,32 +54,54 @@ std::unique_ptr<Expression> literal(std::initializer_list<const char *> value) {
     return literal(values);
 }
 
-std::unique_ptr<Expression> assertion(type::Type type, std::unique_ptr<Expression> value) {
-    return std::make_unique<Assertion>(type, vec(std::move(value)));
+std::unique_ptr<Expression> assertion(type::Type type,
+                                      std::unique_ptr<Expression> value,
+                                      optional<std::unique_ptr<Expression>> def) {
+    std::vector<std::unique_ptr<Expression>> v  = vec(std::move(value));
+    if (def) {
+        v.push_back(std::move(*def));
+    }
+    return std::make_unique<Assertion>(type, std::move(v));
+}
+
+std::unique_ptr<Expression> number(std::unique_ptr<Expression> value,
+                                   optional<std::unique_ptr<Expression>> def) {
+    return assertion(type::Number, std::move(value), std::move(def));
 }
 
-std::unique_ptr<Expression> number(std::unique_ptr<Expression> value) {
-    return assertion(type::Number, std::move(value));
+std::unique_ptr<Expression> string(std::unique_ptr<Expression> value,
+                                   optional<std::unique_ptr<Expression>> def) {
+    return assertion(type::String, std::move(value), std::move(def));
 }
 
-std::unique_ptr<Expression> string(std::unique_ptr<Expression> value) {
-    return assertion(type::String, std::move(value));
+std::unique_ptr<Expression> boolean(std::unique_ptr<Expression> value,
+                                    optional<std::unique_ptr<Expression>> def) {
+    return assertion(type::Boolean, std::move(value), std::move(def));
 }
 
-std::unique_ptr<Expression> boolean(std::unique_ptr<Expression> value) {
-    return assertion(type::Boolean, std::move(value));
+std::unique_ptr<Expression> coercion(type::Type type,
+                                     std::unique_ptr<Expression> value,
+                                     optional<std::unique_ptr<Expression>> def) {
+    std::vector<std::unique_ptr<Expression>> v = vec(std::move(value));
+    if (def) {
+        v.push_back(std::move(*def));
+    }
+    return std::make_unique<Coercion>(type, std::move(v));
 }
 
-std::unique_ptr<Expression> toColor(std::unique_ptr<Expression> value) {
-    return std::make_unique<Coercion>(type::Color, vec(std::move(value)));
+std::unique_ptr<Expression> toColor(std::unique_ptr<Expression> value,
+                                    optional<std::unique_ptr<Expression>> def) {
+    return coercion(type::Color, std::move(value), std::move(def));
 }
 
-std::unique_ptr<Expression> toString(std::unique_ptr<Expression> value) {
-    return std::make_unique<Coercion>(type::String, vec(std::move(value)));
+std::unique_ptr<Expression> toString(std::unique_ptr<Expression> value,
+                                     optional<std::unique_ptr<Expression>> def) {
+    return coercion(type::String, std::move(value), std::move(def));
 }
 
-std::unique_ptr<Expression> toFormatted(std::unique_ptr<Expression> value) {
-    return std::make_unique<Coercion>(type::Formatted, vec(std::move(value)));
+std::unique_ptr<Expression> toFormatted(std::unique_ptr<Expression> value,
+                                        optional<std::unique_ptr<Expression>> def) {
+    return coercion(type::Formatted, std::move(value), std::move(def));
 }
     
 std::unique_ptr<Expression> get(const char* value) {