fix: wrap std::vector<unsigned char> as uint8array in js

Author: Bilb

src/utilities.cpp

@@ -88,8 +88,8 @@ std::optional<std::string> maybeNonemptyString(Napi::Value x, const std::string&
     throw std::invalid_argument{"maybeNonemptyString with invalid type, called from " + identifier};
 }
 
-// Converts to a std::span<const unsigned char> that views directly into the Uint8Array data of `x`.  Throws if x is
-// not a Uint8Array.  The view must not be used beyond the lifetime of `x`.
+// Converts to a std::span<const unsigned char> that views directly into the Uint8Array data of `x`.
+// Throws if x is not a Uint8Array.  The view must not be used beyond the lifetime of `x`.
 std::span<const unsigned char> toCppBufferView(Napi::Value x, const std::string& identifier) {
     if (x.IsNull() || x.IsUndefined())
         throw std::invalid_argument(
@@ -106,7 +106,8 @@ std::vector<unsigned char> toCppBuffer(Napi::Value x, const std::string& identif
     return session::to_vector(toCppBufferView(x, std::move(identifier)));
 }
 
-std::optional<std::vector<unsigned char>> maybeNonemptyBuffer(Napi::Value x, const std::string& identifier) {
+std::optional<std::vector<unsigned char>> maybeNonemptyBuffer(
+        Napi::Value x, const std::string& identifier) {
     if (x.IsNull() || x.IsUndefined())
         return std::nullopt;
 

src/utilities.hpp

@@ -68,7 +68,8 @@ std::optional<std::string> maybeNonemptyString(Napi::Value x, const std::string&
 
 // If the object is null/undef/empty returns nullopt, otherwise if a Uint8Array returns a
 // std::vector<unsigned char> of the value.  Throws if something else.
-std::optional<std::vector<unsigned char>> maybeNonemptyBuffer(Napi::Value x, const std::string& identifier);
+std::optional<std::vector<unsigned char>> maybeNonemptyBuffer(
+        Napi::Value x, const std::string& identifier);
 
 // Implementation struct of toJs(); we add specializations of this for any C++ types we want to be
 // able to convert into JS types.
@@ -121,14 +122,24 @@ struct toJs_impl<T, std::enable_if_t<std::is_convertible_v<T, std::string_view>>
 };
 
 template <typename T>
-struct toJs_impl<T, std::enable_if_t<
-    std::is_convertible_v<T, std::span<const unsigned char>> &&
-    !std::is_same_v<std::remove_cv_t<T>, std::vector<unsigned char>>>> {
+struct toJs_impl<
+        T,
+        std::enable_if_t<
+                std::is_convertible_v<T, std::span<const unsigned char>> &&
+                !std::is_same_v<std::remove_cv_t<T>, std::vector<unsigned char>>>> {
     auto operator()(const Napi::Env& env, std::span<const unsigned char> b) const {
         return Napi::Buffer<uint8_t>::Copy(env, b.data(), b.size());
     }
 };
 
+// this wrap std::vector<unsigned char> to Uint8array in the js world
+template <>
+struct toJs_impl<std::vector<unsigned char>> {
+    auto operator()(const Napi::Env& env, std::vector<unsigned char> b) const {
+        return Napi::Buffer<uint8_t>::Copy(env, b.data(), b.size());
+    }
+};
+
 template <typename T>
 struct toJs_impl<T, std::enable_if_t<std::is_base_of_v<Napi::Value, T>>> {
     auto operator()(const Napi::Env& env, const T& val) { return val; }