From e0a60edbccb47e855ef7a70fbd86bcfa62d18774 Mon Sep 17 00:00:00 2001
From: Tony Gorez <gorez.tony@gmail.com>
Date: Fri, 22 Mar 2024 15:38:03 +0100
Subject: [PATCH] feat(value): expose to_json_string

Signed-off-by: Tony Gorez <gorez.tony@gmail.com>
---
 src/engine/include/includejs/engine_value.h   |  1 +
 src/engine/javascript_core/engine_value.cc    | 29 +++++++++++++++
 test/engine/CMakeLists.txt                    |  3 +-
 .../engine_context_to_json_string_test.cc     | 36 +++++++++++++++++++
 4 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 test/engine/engine_context_to_json_string_test.cc

diff --git a/src/engine/include/includejs/engine_value.h b/src/engine/include/includejs/engine_value.h
index a875e7a..e6512d7 100644
--- a/src/engine/include/includejs/engine_value.h
+++ b/src/engine/include/includejs/engine_value.h
@@ -64,6 +64,7 @@ class INCLUDEJS_ENGINE_EXPORT Value {
   auto push(Value value) -> void;
   auto to_map() const -> std::map<std::string, Value>;
   auto to_vector() const -> std::vector<Value>;
+  auto to_json_string() const -> std::string;
 
   // For internal use only
 #ifndef DOXYGEN
diff --git a/src/engine/javascript_core/engine_value.cc b/src/engine/javascript_core/engine_value.cc
index 9a1a81a..db3cf08 100644
--- a/src/engine/javascript_core/engine_value.cc
+++ b/src/engine/javascript_core/engine_value.cc
@@ -436,6 +436,35 @@ auto Value::push(Value value) -> void {
   assert(!exception);
 }
 
+auto Value::to_json_string() const -> std::string {
+  assert(is_object());
+
+  JSValueRef exception = nullptr;
+  JSStringRef json_string = JSValueCreateJSONString(
+      this->internal->context, this->internal->value, 0, &exception);
+
+  if (exception) {
+    JSStringRef error_message =
+        JSValueToStringCopy(this->internal->context, exception, nullptr);
+    JSStringRelease(json_string);
+    throw std::runtime_error(js_string_to_std_string(error_message));
+  }
+
+  if (!json_string) {
+    JSStringRelease(json_string);
+    return "";
+  }
+
+  try {
+    std::string result{js_string_to_std_string(json_string)};
+    JSStringRelease(json_string);
+    return result;
+  } catch (const std::exception &) {
+    JSStringRelease(json_string);
+    throw std::runtime_error("Failed to convert to JSON string");
+  }
+}
+
 auto Value::native() const -> const void * {
   return static_cast<const void *>(this->internal->value);
 }
diff --git a/test/engine/CMakeLists.txt b/test/engine/CMakeLists.txt
index 409d266..0c80352 100644
--- a/test/engine/CMakeLists.txt
+++ b/test/engine/CMakeLists.txt
@@ -13,7 +13,8 @@ add_executable(includejs_engine_unit
   engine_value_undefined_test.cc
   engine_value_type_test.cc
   engine_value_null_test.cc
-  engine_context_from_json_test.cc)
+  engine_context_from_json_test.cc
+  engine_context_to_json_string_test.cc)
 
 includejs_add_compile_options(includejs_engine_unit)
 
diff --git a/test/engine/engine_context_to_json_string_test.cc b/test/engine/engine_context_to_json_string_test.cc
new file mode 100644
index 0000000..111b312
--- /dev/null
+++ b/test/engine/engine_context_to_json_string_test.cc
@@ -0,0 +1,36 @@
+#include <stdexcept>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <includejs/engine.h>
+
+TEST(IncludeJS_Engine, to_json_string_object) {
+  includejs::Engine engine;
+  auto obj = engine.context().make_object();
+  obj.set("foo", engine.context().from("bar"));
+
+  auto json_object = obj.to_json_string();
+  EXPECT_EQ(json_object, "{\"foo\":\"bar\"}");
+}
+
+TEST(IncludeJS_Engine, to_json_skip_function_in_object) {
+  includejs::Engine engine;
+  auto obj = engine.context().make_object();
+  obj.set("bar", [&engine](std::vector<includejs::Value>) {
+    return engine.context().from("baz");
+  });
+
+  auto json = obj.to_json_string();
+  EXPECT_EQ(json, "{}");
+}
+
+TEST(IncludeJS_Engine, to_json_string_array) {
+  includejs::Engine engine;
+  auto arr = engine.context().make_array();
+  arr.push(engine.context().from("foo"));
+  arr.push(engine.context().from("bar"));
+
+  auto json_array = arr.to_json_string();
+  EXPECT_EQ(json_array, "[\"foo\",\"bar\"]");
+}