fix: 🐛 .unlink() should not delete empty directories

packages/fs-core/src/Superblock.ts

@@ -653,8 +653,7 @@ export class Superblock {
 
   public readonly unlink = (filename: string) => {
     const link: Link = this.getLinkOrThrow(filename, 'unlink');
-    // TODO: Check if it is file, dir, other...
-    if (link.length) throw Error('Dir not empty...');
+    if (link.getNode().isDirectory()) throw createError(ERROR_CODE.EPERM, 'unlink', filename);
     this._emitDeleteRecursive(link);
     this.deleteLink(link);
     const node = link.getNode();

packages/fs-node/src/__tests__/Stats.test.ts

@@ -48,6 +48,7 @@ describe('Stats', () => {
 
     it('keeps birthtime and ctime as separate instances even when equal', () => {
       const { node } = setup();
+      node.ctime = new Date(node.btime.getTime());
       const stats = Stats.build(node, false);
       expect(stats.birthtime.getTime()).toBe(stats.ctime.getTime());
       expect(stats.birthtime).not.toBe(stats.ctime);

packages/fs-node/src/__tests__/volume/unlinkSync.test.ts

@@ -0,0 +1,89 @@
+import { create } from '../util';
+
+describe('unlinkSync', () => {
+  it('removes a file', () => {
+    const vol = create({
+      '/foo.txt': 'bar',
+      '/baz.txt': 'qux',
+    });
+    vol.unlinkSync('/foo.txt');
+    expect(vol.toJSON()).toEqual({
+      '/baz.txt': 'qux',
+    });
+  });
+
+  it('throws ENOENT when file does not exist', () => {
+    const vol = create({
+      '/foo.txt': 'bar',
+    });
+    expect(() => vol.unlinkSync('/bar.txt')).toThrowError(
+      new Error("ENOENT: no such file or directory, unlink '/bar.txt'"),
+    );
+  });
+
+  describe('when path is a directory', () => {
+    it('throws EPERM for an empty directory', () => {
+      const vol = create({});
+      vol.mkdirSync('/dir');
+      expect(() => vol.unlinkSync('/dir')).toThrowError(new Error("EPERM: operation not permitted, unlink '/dir'"));
+      expect(vol.existsSync('/dir')).toBe(true);
+    });
+
+    it('throws EPERM for a non-empty directory', () => {
+      const vol = create({
+        '/dir/foo.txt': 'bar',
+      });
+      expect(() => vol.unlinkSync('/dir')).toThrowError(new Error("EPERM: operation not permitted, unlink '/dir'"));
+      expect(vol.toJSON()).toEqual({
+        '/dir/foo.txt': 'bar',
+      });
+    });
+
+    it('throws EPERM for the root directory', () => {
+      const vol = create({
+        '/foo.txt': 'bar',
+      });
+      expect(() => vol.unlinkSync('/')).toThrowError(new Error("EPERM: operation not permitted, unlink '/'"));
+    });
+
+    it('has an EPERM error code', () => {
+      const vol = create({});
+      vol.mkdirSync('/dir');
+      try {
+        vol.unlinkSync('/dir');
+        throw new Error('not this error');
+      } catch (error) {
+        expect(error.code).toBe('EPERM');
+        expect(error.path).toBe('/dir');
+      }
+    });
+
+    it('removes a symlink pointing to a directory', () => {
+      const vol = create({
+        '/dir/foo.txt': 'bar',
+      });
+      vol.symlinkSync('/dir', '/link');
+      vol.unlinkSync('/link');
+      expect(vol.existsSync('/link')).toBe(false);
+      expect(vol.existsSync('/dir')).toBe(true);
+    });
+  });
+
+  it('async unlink of a directory returns EPERM', done => {
+    const vol = create({});
+    vol.mkdirSync('/dir');
+    vol.unlink('/dir', err => {
+      expect((err as any).code).toBe('EPERM');
+      expect(vol.existsSync('/dir')).toBe(true);
+      done();
+    });
+  });
+
+  it('promises unlink of a directory rejects with EPERM', async () => {
+    const vol = create({});
+    vol.mkdirSync('/dir');
+    await expect(vol.promises.unlink('/dir')).rejects.toThrowError(
+      new Error("EPERM: operation not permitted, unlink '/dir'"),
+    );
+  });
+});