src: add public API for linked bindings

(Re-?)add a public API for creating linked bindings (access to
`NM_F_LINKED` as a constant was previously removed in
d6ac8a4db0c0a588258f594dc21fbd8018bef7c2), and add a test for
the functionality.

PR-URL: https://github.com/nodejs/node/pull/26457
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Shelley Vohr <codebytere@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/test/cctest/test_linked_binding.cc b/test/cctest/test_linked_binding.cc
new file mode 100644
index 0000000000..e0b46d3822
--- /dev/null
+++ b/test/cctest/test_linked_binding.cc
@@ -0,0 +1,42 @@
+#include "node_test_fixture.h"
+#include "node_internals.h"  // RunBootstrapping()
+
+void InitializeBinding(v8::Local<v8::Object> exports,
+                       v8::Local<v8::Value> module,
+                       v8::Local<v8::Context> context) {
+  v8::Isolate* isolate = context->GetIsolate();
+  exports->Set(
+      context,
+      v8::String::NewFromOneByte(isolate,
+                                 reinterpret_cast<const uint8_t*>("key"),
+                                 v8::NewStringType::kNormal).ToLocalChecked(),
+      v8::String::NewFromOneByte(isolate,
+                                 reinterpret_cast<const uint8_t*>("value"),
+                                 v8::NewStringType::kNormal).ToLocalChecked())
+      .FromJust();
+}
+
+NODE_MODULE_LINKED(cctest_linkedbinding, InitializeBinding);
+
+class LinkedBindingTest : public EnvironmentTestFixture {};
+
+TEST_F(LinkedBindingTest, SimpleTest) {
+  const v8::HandleScope handle_scope(isolate_);
+  const Argv argv;
+  Env test_env {handle_scope, argv};
+
+  v8::Local<v8::Context> context = isolate_->GetCurrentContext();
+
+  const char* run_script =
+      "process._linkedBinding('cctest_linkedbinding').key";
+  v8::Local<v8::Script> script = v8::Script::Compile(
+      context,
+      v8::String::NewFromOneByte(isolate_,
+                                 reinterpret_cast<const uint8_t*>(run_script),
+                                 v8::NewStringType::kNormal).ToLocalChecked())
+      .ToLocalChecked();
+  v8::Local<v8::Value> completion_value = script->Run(context).ToLocalChecked();
+  v8::String::Utf8Value utf8val(isolate_, completion_value);
+  CHECK_NOT_NULL(*utf8val);
+  CHECK_EQ(strcmp(*utf8val, "value"), 0);
+}