From caff930d47eb722096634b3d074bfb0afce867b1 Mon Sep 17 00:00:00 2001
From: cjihrig <cjihrig@gmail.com>
Date: Sat, 18 Nov 2017 01:39:02 -0500
Subject: [PATCH] module: replace default paths in require.resolve()

Prior to this commit, the default search paths would be included
in the require.resolve() process, even if user specified paths
were provided. This commit causes the default paths to be
omitted by using a fake parent module.

Refs: https://github.com/nodejs/node/issues/5963
PR-URL: https://github.com/nodejs/node/pull/17113
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 lib/module.js                                 |  5 ++++-
 .../default/node_modules/dep/index.js         |  0
 .../resolve-paths/default/verify-paths.js     | 21 +++++++++++++++++++
 .../defined/node_modules/dep/index.js         |  0
 test/parallel/test-require-resolve.js         |  1 +
 5 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 test/fixtures/resolve-paths/default/node_modules/dep/index.js
 create mode 100644 test/fixtures/resolve-paths/default/verify-paths.js
 create mode 100644 test/fixtures/resolve-paths/defined/node_modules/dep/index.js

diff --git a/lib/module.js b/lib/module.js
index e418a1a3e08440..0f63fe9a2ca2f5 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -518,11 +518,14 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 
   if (typeof options === 'object' && options !== null &&
       Array.isArray(options.paths)) {
+    const fakeParent = new Module('', null);
+
     paths = [];
 
     for (var i = 0; i < options.paths.length; i++) {
       const path = options.paths[i];
-      const lookupPaths = Module._resolveLookupPaths(path, parent, true);
+      fakeParent.paths = Module._nodeModulePaths(path);
+      const lookupPaths = Module._resolveLookupPaths(request, fakeParent, true);
 
       if (!paths.includes(path))
         paths.push(path);
diff --git a/test/fixtures/resolve-paths/default/node_modules/dep/index.js b/test/fixtures/resolve-paths/default/node_modules/dep/index.js
new file mode 100644
index 00000000000000..e69de29bb2d1d6
diff --git a/test/fixtures/resolve-paths/default/verify-paths.js b/test/fixtures/resolve-paths/default/verify-paths.js
new file mode 100644
index 00000000000000..dee03fbfe3b6b4
--- /dev/null
+++ b/test/fixtures/resolve-paths/default/verify-paths.js
@@ -0,0 +1,21 @@
+'use strict';
+require('../../../common');
+const assert = require('assert');
+const path = require('path');
+
+// By default, resolving 'dep' should return
+// fixturesDir/resolve-paths/default/node_modules/dep/index.js. By setting
+// the path to fixturesDir/resolve-paths/default, the 'default' directory
+// structure should be ignored.
+
+assert.strictEqual(
+  require.resolve('dep'),
+  path.join(__dirname, 'node_modules', 'dep', 'index.js')
+);
+
+const paths = [path.resolve(__dirname, '..', 'defined')];
+
+assert.strictEqual(
+  require.resolve('dep', { paths }),
+  path.join(paths[0], 'node_modules', 'dep', 'index.js')
+);
diff --git a/test/fixtures/resolve-paths/defined/node_modules/dep/index.js b/test/fixtures/resolve-paths/defined/node_modules/dep/index.js
new file mode 100644
index 00000000000000..e69de29bb2d1d6
diff --git a/test/parallel/test-require-resolve.js b/test/parallel/test-require-resolve.js
index 6f2253a4e27083..4fbf697faf51b6 100644
--- a/test/parallel/test-require-resolve.js
+++ b/test/parallel/test-require-resolve.js
@@ -37,3 +37,4 @@ assert.strictEqual('path', require.resolve('path'));
 
 // Test configurable resolve() paths.
 require(fixtures.path('require-resolve.js'));
+require(fixtures.path('resolve-paths', 'default', 'verify-paths.js'));