module: Change precedence of _-prefixed modules

That way stat() only needs to be called once in most cases (assuming non
_-prefixed symlinks are more common).

Author: alexanderGugel

lib/module.js

@@ -198,8 +198,8 @@ Module._findPath = function(request, paths, isMain) {
     const _basePath = path.resolve(curPath, '_' + request);
     const basePath = path.resolve(curPath, request);
 
-    const filename = tryFindPath(_basePath, exts, true, isAbsolute) ||
-      tryFindPath(basePath, exts, isMain, isAbsolute);
+    const filename = tryFindPath(basePath, exts, isMain, isAbsolute) ||
+      tryFindPath(_basePath, exts, true, isAbsolute);
 
     if (filename) {
       // Warn once if '.' resolved outside the module dir

…l-path/node_modules/real-module/index.js …l-path/node_modules/link-module/index.jstest/fixtures/module-require-real-path/node_modules/real-module/index.js renamed to test/fixtures/module-require-real-path/node_modules/link-module/index.js test/fixtures/module-require-real-path/node_modules/real-module/index.js renamed to test/fixtures/module-require-real-path/node_modules/link-module/index.js

@@ -7,6 +7,9 @@ const fs = require('fs');
 const realModuleSymlinkPath = path.join(common.fixturesDir,
   '/module-require-real-path/node_modules/_real-module');
 
+const linkModuleSymlinkPath = path.join(common.fixturesDir,
+  '/module-require-real-path/node_modules/_link-module');
+
 const localRealModulePath = path.join(common.fixturesDir,
   '/module-require-real-path/real-module');
 
@@ -18,13 +21,15 @@ const _require = require(
 
 process.on('exit', function() {
   fs.unlinkSync(realModuleSymlinkPath);
+  fs.unlinkSync(linkModuleSymlinkPath);
 });
 
 fs.symlinkSync('../real-module', realModuleSymlinkPath);
+fs.symlinkSync('../real-module', linkModuleSymlinkPath);
 
 assert.equal(_require('./real-module'), _require('real-module'));
 assert.equal(_require('real-module').dirname, localRealModulePath);
 
 // When required directly with the _-prefix, resolve to path of symlink.
-assert.notEqual(_require('./real-module'), _require('_real-module'));
-assert.equal(_require('_real-module').dirname, realModuleSymlinkPath);
+assert.notEqual(_require('./real-module'), _require('_link-module'));
+assert.equal(_require('_link-module').dirname, linkModuleSymlinkPath);