From cf8e5356d9fbbdca40d9b9fe062b3c292b7e91e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vinicius=20Louren=C3=A7o?=
 <12551007+H4ad@users.noreply.github.com>
Date: Fri, 19 Jul 2024 21:22:24 -0300
Subject: [PATCH] lib: improve error message when index not found on cjs

PR-URL: https://github.com/nodejs/node/pull/53859
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
---
 src/node_file.cc                             | 15 ++++++++-------
 test/es-module/test-cjs-legacyMainResolve.js | 17 +++++++++++++++--
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/node_file.cc b/src/node_file.cc
index f90283e9f2a54a..0839463d5079e3 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -3185,6 +3185,8 @@ void BindingData::LegacyMainResolve(const FunctionCallbackInfo<Value>& args) {
     return;
   }
 
+  std::string package_initial_file = "";
+
   ada::result<ada::url_aggregator> file_path_url;
   std::optional<std::string> initial_file_path;
   std::string file_path;
@@ -3207,6 +3209,8 @@ void BindingData::LegacyMainResolve(const FunctionCallbackInfo<Value>& args) {
 
     FromNamespacedPath(&initial_file_path.value());
 
+    package_initial_file = *initial_file_path;
+
     for (int i = 0; i < legacy_main_extensions_with_main_end; i++) {
       file_path = *initial_file_path + std::string(legacy_main_extensions[i]);
 
@@ -3262,13 +3266,10 @@ void BindingData::LegacyMainResolve(const FunctionCallbackInfo<Value>& args) {
     }
   }
 
-  std::optional<std::string> module_path =
-      node::url::FileURLToPath(env, *package_json_url);
-  std::optional<std::string> module_base;
+  if (package_initial_file == "")
+    package_initial_file = *initial_file_path + ".js";
 
-  if (!module_path.has_value()) {
-    return;
-  }
+  std::optional<std::string> module_base;
 
   if (args.Length() >= 3 && args[2]->IsString()) {
     Utf8Value utf8_base_path(isolate, args[2]);
@@ -3293,7 +3294,7 @@ void BindingData::LegacyMainResolve(const FunctionCallbackInfo<Value>& args) {
 
   THROW_ERR_MODULE_NOT_FOUND(isolate,
                              "Cannot find package '%s' imported from %s",
-                             *module_path,
+                             package_initial_file,
                              *module_base);
 }
 
diff --git a/test/es-module/test-cjs-legacyMainResolve.js b/test/es-module/test-cjs-legacyMainResolve.js
index 1dc7d8faafe6eb..0bfeb567a22b1f 100644
--- a/test/es-module/test-cjs-legacyMainResolve.js
+++ b/test/es-module/test-cjs-legacyMainResolve.js
@@ -129,7 +129,7 @@ describe('legacyMainResolve', () => {
     );
     assert.throws(
       () => legacyMainResolve(packageJsonUrl, { main: null }, packageJsonUrl),
-      { code: 'ERR_MODULE_NOT_FOUND' },
+      { message: /index\.js/, code: 'ERR_MODULE_NOT_FOUND' },
     );
   });
 
@@ -137,7 +137,20 @@ describe('legacyMainResolve', () => {
     const packageJsonUrl = pathToFileURL('/c/file%20with%20percents/package.json');
     assert.throws(
       () => legacyMainResolve(packageJsonUrl, { main: null }, packageJsonUrl),
-      { code: 'ERR_MODULE_NOT_FOUND' },
+      { message: /index\.js/, code: 'ERR_MODULE_NOT_FOUND' },
+    );
+  });
+
+  it('should report main file on error message when not found', () => {
+    const packageJsonUrl = pathToFileURL(
+      path.resolve(
+        fixtures.path('/es-modules/legacy-main-resolver'),
+        'package.json'
+      )
+    );
+    assert.throws(
+      () => legacyMainResolve(packageJsonUrl, { main: './index.node' }, packageJsonUrl),
+      { message: /index\.node/, code: 'ERR_MODULE_NOT_FOUND' },
     );
   });