From 75487f0db80e70a3e27fabfe323a33258dfbbea8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Zasso?= <targos@protonmail.com>
Date: Fri, 15 Apr 2016 13:32:36 +0200
Subject: [PATCH] module: fix resolution of filename with trailing slash

A recent optimization of module loading performance [1] forgot to check that
extensions were set in a certain code path.

[1] https://github.com/nodejs/node/pull/5172/commits/ae18bbef48d87d9c641df85369f62cfd5ed8c250

Fixes: https://github.com/nodejs/node/issues/6214
PR-URL: https://github.com/nodejs/node/pull/6215
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>
---
 lib/module.js                                 |  2 ++
 .../node_modules/module1/package.json         |  3 +++
 .../module-require/not-found/trailingSlash.js |  1 +
 test/parallel/test-require-exceptions.js      | 24 ++++++++++++++-----
 4 files changed, 24 insertions(+), 6 deletions(-)
 create mode 100644 test/fixtures/module-require/not-found/node_modules/module1/package.json
 create mode 100644 test/fixtures/module-require/not-found/trailingSlash.js

diff --git a/lib/module.js b/lib/module.js
index 29a23776d7..f633d62c49 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -170,6 +170,8 @@ Module._findPath = function(request, paths) {
     }
 
     if (!filename) {
+      if (exts === undefined)
+        exts = Object.keys(Module._extensions);
       filename = tryPackage(basePath, exts);
     }
 
diff --git a/test/fixtures/module-require/not-found/node_modules/module1/package.json b/test/fixtures/module-require/not-found/node_modules/module1/package.json
new file mode 100644
index 0000000000..b5018d73b2
--- /dev/null
+++ b/test/fixtures/module-require/not-found/node_modules/module1/package.json
@@ -0,0 +1,3 @@
+{
+  "main": "doesnotexist"
+}
diff --git a/test/fixtures/module-require/not-found/trailingSlash.js b/test/fixtures/module-require/not-found/trailingSlash.js
new file mode 100644
index 0000000000..4ac6cba9ca
--- /dev/null
+++ b/test/fixtures/module-require/not-found/trailingSlash.js
@@ -0,0 +1 @@
+require('module1/');
diff --git a/test/parallel/test-require-exceptions.js b/test/parallel/test-require-exceptions.js
index e7a191b47a..0e61ad2f3f 100644
--- a/test/parallel/test-require-exceptions.js
+++ b/test/parallel/test-require-exceptions.js
@@ -14,9 +14,21 @@ assert.throws(function() {
 
 // Requiring a module that does not exist should throw an
 // error with its `code` set to MODULE_NOT_FOUND
-assert.throws(function() {
-  require(common.fixturesDir + '/DOES_NOT_EXIST');
-}, function(e) {
-  assert.equal('MODULE_NOT_FOUND', e.code);
-  return true;
-});
+assertModuleNotFound('/DOES_NOT_EXIST');
+
+assertExists('/module-require/not-found/trailingSlash.js');
+assertExists('/module-require/not-found/node_modules/module1/package.json');
+assertModuleNotFound('/module-require/not-found/trailingSlash');
+
+function assertModuleNotFound(path) {
+  assert.throws(function() {
+    require(common.fixturesDir + path);
+  }, function(e) {
+    assert.strictEqual(e.code, 'MODULE_NOT_FOUND');
+    return true;
+  });
+}
+
+function assertExists(fixture) {
+  assert(common.fileExists(common.fixturesDir + fixture));
+}