[Fix] node-modules-paths: opts should be optional, and opts.paths should not be concatenated when omitted.

Fixes #96.

Author: ljharb

lib/node-modules-paths.js

@@ -1,7 +1,7 @@
 var path = require('path');
 
-module.exports = function (start, opts) {
-    var modules = opts.moduleDirectory
+module.exports = function nodeModulesPaths(start, opts) {
+    var modules = opts && opts.moduleDirectory
         ? [].concat(opts.moduleDirectory)
         : ['node_modules']
     ;
@@ -34,5 +34,5 @@ module.exports = function (start, opts) {
     if (process.platform === 'win32') {
         dirs[dirs.length - 1] = dirs[dirs.length - 1].replace(':', ':\\');
     }
-    return dirs.concat(opts.paths);
+    return opts && opts.paths ? dirs.concat(opts.paths) : dirs;
 };

test/node-modules-paths.js

@@ -0,0 +1,76 @@
+var test = require('tape');
+var path = require('path');
+
+var getAllNodeModulePathsUpwards = function (start, moduleDirectory) {
+  if (!moduleDirectory) { moduleDirectory = 'node_modules'; }
+  var currentPath = start;
+  var expectedDirs = ['/' + path.join(currentPath, moduleDirectory)];
+  while (currentPath && currentPath !== '/') {
+    currentPath = path.join(currentPath, '../');
+    expectedDirs.push('/' + path.join(currentPath, moduleDirectory));
+  }
+  return expectedDirs;
+}
+
+var nodeModulesPaths = require('../lib/node-modules-paths');
+
+test('node-modules-paths', function (t) {
+  t.test('no options', function (t) {
+    var start = path.join(__dirname, 'resolver');
+    var dirs = nodeModulesPaths(start);
+
+    var expectedDirs = getAllNodeModulePathsUpwards(start);
+
+    t.deepEqual(dirs, expectedDirs);
+
+    t.end();
+  });
+
+  t.test('empty options', function (t) {
+    var start = path.join(__dirname, 'resolver');
+    var dirs = nodeModulesPaths(start, {});
+
+    var expectedDirs = getAllNodeModulePathsUpwards(start);
+
+    t.deepEqual(dirs, expectedDirs);
+
+    t.end();
+  });
+
+  t.test('with paths option', function (t) {
+    var start = path.join(__dirname, 'resolver');
+    var paths = ['a', 'b'];
+    var dirs = nodeModulesPaths(start, { paths: paths });
+
+    var expectedDirs = getAllNodeModulePathsUpwards(start);
+
+    t.deepEqual(dirs, expectedDirs.concat(paths));
+
+    t.end();
+  });
+
+  t.test('with moduleDirectory option', function (t) {
+    var start = path.join(__dirname, 'resolver');
+    var paths = ['a', 'b'];
+    var dirs = nodeModulesPaths(start, { paths: paths });
+
+    var expectedDirs = getAllNodeModulePathsUpwards(start);
+
+    t.deepEqual(dirs, expectedDirs.concat(paths));
+
+    t.end();
+  });
+
+  t.test('with moduleDirectory and paths options', function (t) {
+    var start = path.join(__dirname, 'resolver');
+    var paths = ['a', 'b'];
+    var moduleDirectory = 'not node modules';
+    var dirs = nodeModulesPaths(start, { paths: paths, moduleDirectory: moduleDirectory });
+
+    var expectedDirs = getAllNodeModulePathsUpwards(start, moduleDirectory);
+
+    t.deepEqual(dirs, expectedDirs.concat(paths));
+
+    t.end();
+  });
+});