src: allow embedders to disable esm loader

PR-URL: https://github.com/nodejs/node/pull/34060
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>

4 files changed, 16 insertions, 1 deletions

diff --git a/src/env-inl.h b/src/env-inl.h
index 5cbb2cd60b..690e797043 100644
--- a/src/env-inl.h
+++ b/src/env-inl.h
@@ -767,6 +767,10 @@ inline bool Environment::is_main_thread() const {
   return worker_context() == nullptr;
 }
 
+inline bool Environment::should_not_register_esm_loader() const {
+  return flags_ & EnvironmentFlags::kNoRegisterESMLoader;
+}
+
 inline bool Environment::owns_process_state() const {
   return flags_ & EnvironmentFlags::kOwnsProcessState;
 }
diff --git a/src/env.h b/src/env.h
index 175e1a3f8d..2add16c8ed 100644
--- a/src/env.h
+++ b/src/env.h
@@ -1054,6 +1054,7 @@ class Environment : public MemoryRetainer {
   inline void set_has_serialized_options(bool has_serialized_options);
 
   inline bool is_main_thread() const;
+  inline bool should_not_register_esm_loader() const;
   inline bool owns_process_state() const;
   inline bool owns_inspector() const;
   inline uint64_t thread_id() const;
diff --git a/src/node.h b/src/node.h
index b3b7c0c169..6a6a40113b 100644
--- a/src/node.h
+++ b/src/node.h
@@ -408,7 +408,11 @@ enum Flags : uint64_t {
   // Set if this Environment instance is associated with the global inspector
   // handling code (i.e. listening on SIGUSR1).
   // This is set when using kDefaultFlags.
-  kOwnsInspector = 1 << 2
+  kOwnsInspector = 1 << 2,
+  // Set if Node.js should not run its own esm loader. This is needed by some
+  // embedders, because it's possible for the Node.js esm loader to conflict
+  // with another one in an embedder environment, e.g. Blink's in Chromium.
+  kNoRegisterESMLoader = 1 << 3
 };
 }  // namespace EnvironmentFlags
 
diff --git a/src/node_options.cc b/src/node_options.cc
index d7434b4b12..913366b350 100644
--- a/src/node_options.cc
+++ b/src/node_options.cc
@@ -979,6 +979,12 @@ void Initialize(Local<Object> target,
           context, FIXED_ONE_BYTE_STRING(isolate, "envSettings"), env_settings)
       .Check();
 
+  target
+      ->Set(context,
+            FIXED_ONE_BYTE_STRING(env->isolate(), "shouldNotRegisterESMLoader"),
+            Boolean::New(isolate, env->should_not_register_esm_loader()))
+      .Check();
+
   Local<Object> types = Object::New(isolate);
   NODE_DEFINE_CONSTANT(types, kNoOp);
   NODE_DEFINE_CONSTANT(types, kV8Option);