feat(node): stabilize detecting if CJS via `"type": "commonjs"` in a package.json (#26439)

This will respect `"type": "commonjs"` in a package.json to determine if
`.js`/`.jsx`/`.ts`/.tsx` files are CJS or ESM. If the file is found to
be ESM it will be loaded as ESM though.

2 files changed, 5 insertions, 28 deletions

diff --git a/ext/node/polyfills/01_require.js b/ext/node/polyfills/01_require.js
index 0d267ca44..083d4e49b 100644
--- a/ext/node/polyfills/01_require.js
+++ b/ext/node/polyfills/01_require.js
@@ -11,6 +11,7 @@ import {
   op_require_can_parse_as_esm,
   op_require_init_paths,
   op_require_is_deno_dir_package,
+  op_require_is_maybe_cjs,
   op_require_is_request_relative,
   op_require_node_module_paths,
   op_require_package_imports_resolve,
@@ -19,7 +20,6 @@ import {
   op_require_path_is_absolute,
   op_require_path_resolve,
   op_require_proxy_path,
-  op_require_read_closest_package_json,
   op_require_read_file,
   op_require_read_package_scope,
   op_require_real_path,
@@ -1060,36 +1060,13 @@ Module.prototype._compile = function (content, filename, format) {
   return result;
 };
 
-Module._extensions[".js"] = function (module, filename) {
-  const content = op_require_read_file(filename);
-
-  let format;
-  if (StringPrototypeEndsWith(filename, ".js")) {
-    const pkg = op_require_read_closest_package_json(filename);
-    if (pkg?.type === "module") {
-      format = "module";
-    } else if (pkg?.type === "commonjs") {
-      format = "commonjs";
-    }
-  }
-
-  module._compile(content, filename, format);
-};
-
-Module._extensions[".ts"] =
+Module._extensions[".js"] =
+  Module._extensions[".ts"] =
   Module._extensions[".jsx"] =
   Module._extensions[".tsx"] =
     function (module, filename) {
       const content = op_require_read_file(filename);
-
-      let format;
-      const pkg = op_require_read_closest_package_json(filename);
-      if (pkg?.type === "module") {
-        format = "module";
-      } else if (pkg?.type === "commonjs") {
-        format = "commonjs";
-      }
-
+      const format = op_require_is_maybe_cjs(filename) ? undefined : "module";
       module._compile(content, filename, format);
     };
 
diff --git a/ext/node/polyfills/process.ts b/ext/node/polyfills/process.ts
index bf626e410..647376d5c 100644
--- a/ext/node/polyfills/process.ts
+++ b/ext/node/polyfills/process.ts
@@ -919,7 +919,7 @@ Object.defineProperty(argv, "1", {
     if (Deno.mainModule?.startsWith("file:")) {
       return pathFromURL(new URL(Deno.mainModule));
     } else {
-      return join(Deno.cwd(), "$deno$node.js");
+      return join(Deno.cwd(), "$deno$node.mjs");
     }
   },
 });