module: check file ext before dir as documented

The documented resolution algorithm started to search for package.json
files prior to searching for file extensions when searching for a
specifier. Oddly, it did not search for index files at same time it
searched for package.json. This restores the documented behavior of
searching for file extensions prior to searching directories.

PR-URL: https://github.com/nodejs/node/pull/15015
Fixes: https://github.com/nodejs/node/issues/14990
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Khaidi Chu <i@2333.moe>

1 files changed, 8 insertions, 7 deletions

diff --git a/lib/module.js b/lib/module.js
index 468619f2bf..6d4e3dbfcf 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -219,6 +219,9 @@ Module._findPath = function(request, paths, isMain) {
   var exts;
   var trailingSlash = request.length > 0 &&
     request.charCodeAt(request.length - 1) === CHAR_FORWARD_SLASH;
+  if (!trailingSlash) {
+    trailingSlash = /(?:^|\/)\.?\.$/.test(request);
+  }
 
   // For each path
   for (var i = 0; i < paths.length; i++) {
@@ -236,10 +239,6 @@ Module._findPath = function(request, paths, isMain) {
         } else {
           filename = toRealPath(basePath);
         }
-      } else if (rc === 1) {  // Directory.
-        if (exts === undefined)
-          exts = Object.keys(Module._extensions);
-        filename = tryPackage(basePath, exts, isMain);
       }
 
       if (!filename) {
@@ -251,11 +250,13 @@ Module._findPath = function(request, paths, isMain) {
     }
 
     if (!filename && rc === 1) {  // Directory.
+      // try it with each of the extensions at "index"
       if (exts === undefined)
         exts = Object.keys(Module._extensions);
-      filename = tryPackage(basePath, exts, isMain) ||
-        // try it with each of the extensions at "index"
-        tryExtensions(path.resolve(basePath, 'index'), exts, isMain);
+      filename = tryPackage(basePath, exts, isMain);
+      if (!filename) {
+        filename = tryExtensions(path.resolve(basePath, 'index'), exts, isMain);
+      }
     }
 
     if (filename) {