[Fix] error code MODULE_NOT_FOUND instead of ENOTDIR

Fixes #121.

Author: ljharb

lib/async.js

@@ -20,9 +20,11 @@ module.exports = function resolve(x, options, callback) {
 
     var isFile = opts.isFile || function (file, cb) {
         fs.stat(file, function (err, stat) {
-            if (err && err.code === 'ENOENT') cb(null, false);
-            else if (err) cb(err);
-            else cb(null, stat.isFile() || stat.isFIFO());
+            if (!err) {
+                return cb(null, stat.isFile() || stat.isFIFO());
+            }
+            if (err.code === 'ENOENT' || err.code === 'ENOTDIR') return cb(null, false);
+            return cb(err);
         });
     };
     var readFile = opts.readFile || fs.readFile;

lib/sync.js

@@ -13,7 +13,7 @@ module.exports = function (x, options) {
         try {
             var stat = fs.statSync(file);
         } catch (e) {
-            if (e && e.code === 'ENOENT') return false;
+            if (e && (e.code === 'ENOENT' || e.code === 'ENOTDIR')) return false;
             throw e;
         }
         return stat.isFile() || stat.isFIFO();

test/resolver.js

@@ -294,3 +294,34 @@ test('#52 - incorrectly resolves module-paths like "./someFolder/" when there is
         t.equal(res, path.join(dir, 'same_names/foo/index.js'));
     });
 });
+
+test('async: #121 - treating an existing file as a dir when no basedir', function (t) {
+    var testFile = path.basename(__filename);
+
+    t.test('sanity check', function (st) {
+        st.plan(1);
+        resolve('./' + testFile, function (err, res, pkg) {
+            if (err) t.fail(err);
+            st.equal(res, __filename, 'sanity check');
+        });
+    });
+
+    t.test('with a fake directory', function (st) {
+        st.plan(4);
+
+        resolve('./' + testFile + '/blah', function (err, res, pkg) {
+            st.ok(err, 'there is an error');
+            st.notOk(res, 'no result');
+
+            st.equal(err && err.code, 'MODULE_NOT_FOUND', 'error code matches require.resolve');
+            st.equal(
+                err && err.message,
+                'Cannot find module \'./' + testFile + '/blah\' from \'' + __dirname + '\'',
+                'can not find nonexistent module'
+            );
+            st.end();
+        });
+    });
+
+    t.end();
+});

test/resolver_sync.js

@@ -217,3 +217,37 @@ test('#52 - incorrectly resolves module-paths like "./someFolder/" when there is
     );
     t.end();
 });
+
+test('sync: #121 - treating an existing file as a dir when no basedir', function (t) {
+    var testFile = path.basename(__filename);
+
+    t.test('sanity check', function (st) {
+        st.equal(
+            resolve.sync('./' + testFile),
+            __filename,
+            'sanity check'
+        );
+        st.end();
+    });
+
+    t.test('with a fake directory', function (st) {
+        function run() { return resolve.sync('./' + testFile + '/blah'); }
+
+        st.throws(run, 'throws an error');
+
+        try {
+            run();
+        } catch (e) {
+            st.equal(e.code, 'MODULE_NOT_FOUND', 'error code matches require.resolve');
+            st.equal(
+                e.message,
+                'Cannot find module \'./' + testFile + '/blah\' from \'' + __dirname + '\'',
+                'can not find nonexistent module'
+            );
+        }
+
+        st.end();
+    });
+
+    t.end();
+});