From aed9a61c9f88f38f741f8275f743eb2c38298edb Mon Sep 17 00:00:00 2001
From: Aaron Turner <aaron@aaronthedev.com>
Date: Tue, 15 Oct 2019 16:29:21 -0700
Subject: [PATCH] Implemented Syrus' Volume fix

---
 src/__tests__/volume.test.ts | 8 ++++++++
 src/volume.ts                | 8 +++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/volume.test.ts b/src/__tests__/volume.test.ts
index 4f5f473c..6c7d21f9 100644
--- a/src/__tests__/volume.test.ts
+++ b/src/__tests__/volume.test.ts
@@ -3,6 +3,7 @@ import { Link, Node } from '../node';
 import Stats from '../Stats';
 import Dirent from '../Dirent';
 import { Volume, filenameToSteps, StatWatcher } from '../volume';
+import { constants } from '../constants';
 import hasBigInt from './hasBigInt';
 
 describe('volume', () => {
@@ -282,6 +283,13 @@ describe('volume', () => {
         expect(typeof fd).toBe('number');
         expect(fd).toBeGreaterThan(0);
       });
+      it('Create new directory at root (/)', () => {
+        vol.mkdirSync('/abc');
+        const fd = vol.openSync('/abc', constants.O_DIRECTORY);
+        // expect(vol.root.getChild('test.txt')).toBeInstanceOf(Link);
+        expect(typeof fd).toBe('number');
+        expect(fd).toBeGreaterThan(0);
+      });
       it('Error on file not found', () => {
         try {
           vol.openSync('/non-existing-file.txt', 'r');
diff --git a/src/volume.ts b/src/volume.ts
index 7b356902..91c5ed34 100644
--- a/src/volume.ts
+++ b/src/volume.ts
@@ -904,7 +904,13 @@ export class Volume {
     if (!realLink) throwError(ENOENT, 'open', link.getPath());
 
     const node = realLink.getNode();
-    if (node.isDirectory() && flagsNum !== FLAGS.r) throwError(EISDIR, 'open', link.getPath());
+    if (node.isDirectory()) {
+      const isRead = flagsNum === FLAGS.r;
+      const isDir = (flagsNum & constants.O_DIRECTORY) !== 0;
+      if (!isRead && !isDir) {
+        throwError(EISDIR, 'open', link.getPath());
+      }
+    }
 
     // Check node permissions
     if (!(flagsNum & O_WRONLY)) {