fix: some metadata changes not follow common unix filesystem lead to …

…node.watchFile not trigger

1. nlink default value is 2
2. add subfolder nlink++
3. atime updated
4. ctime updated after uid/gid/atime/mtime/perm/nlink updated

#889

src/__tests__/node.test.ts

@@ -1,4 +1,4 @@
-import { Node } from '../node';
+import { Node, Link } from '../node';
 import { constants } from '../constants';
 
 describe('node.ts', () => {
@@ -69,5 +69,31 @@ describe('node.ts', () => {
       expect(node.perm).toBe(0o600);
       expect(node.isFile()).toBe(true);
     });
+    describe.each([['uid'], ['gid'], ['atime'], ['mtime'], ['perm'], ['nlink']])('ctime changes', field => {
+      it(`set ${field}`, () => {
+        const node = new Node(1);
+        const oldCtime = node.ctime;
+        node[field] = 1;
+        const newCtime = node.ctime;
+        expect(newCtime !== oldCtime).toBeTruthy();
+      });
+    });
+
+    describe.each([
+      ['getString', []],
+      ['getBuffer', []],
+      ['read', [Buffer.alloc(0)]],
+    ])('atime changes', (method, args) => {
+      it(`${method}()`, () => {
+        const node = new Node(1);
+        const oldAtime = node.atime;
+        const oldCtime = node.ctime;
+        node[method](...args);
+        const newAtime = node.atime;
+        const newCtime = node.ctime;
+        expect(newAtime !== oldAtime).toBeTruthy();
+        expect(newCtime !== oldCtime).toBeTruthy();
+      });
+    });
   });
 });

src/__tests__/promises.test.ts

@@ -462,7 +462,7 @@ describe('Promises API', () => {
       '/foo/baz': 'baz',
     });
     it('Read an existing directory', async () => {
-      expect(await promises.readdir('/foo')).toEqual(['bar', 'baz']);
+      expect(await promises.readdir('/foo')).toEqual(['.', '..', 'bar', 'baz']);
     });
     it('Reject when directory does not exist', () => {
       return expect(promises.readdir('/bar')).rejects.toBeInstanceOf(Error);

src/__tests__/volume.test.ts

@@ -261,7 +261,7 @@ describe('volume', () => {
         const stat = vol.statSync('/dir');
 
         expect(stat.isDirectory()).toBe(true);
-        expect(vol.readdirSync('/dir')).toEqual([]);
+        expect(vol.readdirSync('/dir')).toEqual(['.', '..']);
       });
     });
 
@@ -332,10 +332,13 @@ describe('volume', () => {
     describe('.openSync(path, flags[, mode])', () => {
       const vol = new Volume();
       it('Create new file at root (/test.txt)', () => {
+        const oldMtime = vol.root.getNode().mtime;
         const fd = vol.openSync('/test.txt', 'w');
+        const newMtime = vol.root.getNode().mtime;
         expect(vol.root.getChild('test.txt')).toBeInstanceOf(Link);
         expect(typeof fd).toBe('number');
         expect(fd).toBeGreaterThan(0);
+        expect(oldMtime !== newMtime).toBeTruthy();
       });
       it('Error on file not found', () => {
         try {
@@ -870,20 +873,20 @@ describe('volume', () => {
         vol.writeFileSync('/1.js', '123');
         vol.writeFileSync('/2.js', '123');
         const list = vol.readdirSync('/');
-        expect(list.length).toBe(2);
-        expect(list).toEqual(['1.js', '2.js']);
+        expect(list.length).toBe(4);
+        expect(list).toEqual(['.', '..', '1.js', '2.js']);
       });
       it('Returns a Dirent list', () => {
         const vol = new Volume();
         vol.writeFileSync('/1', '123');
         vol.mkdirSync('/2');
         const list = vol.readdirSync('/', { withFileTypes: true });
-        expect(list.length).toBe(2);
-        expect(list[0]).toBeInstanceOf(Dirent);
-        const dirent0 = list[0] as Dirent;
+        expect(list.length).toBe(4);
+        expect(list[2]).toBeInstanceOf(Dirent);
+        const dirent0 = list[2] as Dirent;
         expect(dirent0.name).toBe('1');
         expect(dirent0.isFile()).toBe(true);
-        const dirent1 = list[1] as Dirent;
+        const dirent1 = list[3] as Dirent;
         expect(dirent1.name).toBe('2');
         expect(dirent1.isDirectory()).toBe(true);
       });
@@ -989,10 +992,16 @@ describe('volume', () => {
     describe('.mkdirSync(path[, options])', () => {
       it('Create dir at root', () => {
         const vol = new Volume();
+        const oldMtime = vol.root.getNode().mtime;
+        const oldNlink = vol.root.getNode().nlink;
         vol.mkdirSync('/test');
+        const newMtime = vol.root.getNode().mtime;
+        const newNlink = vol.root.getNode().nlink;
         const child = tryGetChild(vol.root, 'test');
         expect(child).toBeInstanceOf(Link);
         expect(child.getNode().isDirectory()).toBe(true);
+        expect(oldMtime !== newMtime).toBeTruthy();
+        expect(newNlink === oldNlink + 1).toBeTruthy;
       });
       it('Create 2 levels deep folders', () => {
         const vol = new Volume();

src/__tests__/volume/readdirSync.test.ts

@@ -7,7 +7,7 @@ describe('readdirSync()', () => {
     });
     const dirs = vol.readdirSync('/');
 
-    expect(dirs).toEqual(['foo']);
+    expect(dirs).toEqual(['.', '..', 'foo']);
   });
 
   it('returns multiple directories', () => {
@@ -20,14 +20,14 @@ describe('readdirSync()', () => {
 
     (dirs as any).sort();
 
-    expect(dirs).toEqual(['ab', 'foo', 'tro']);
+    expect(dirs).toEqual(['.', '..', 'ab', 'foo', 'tro']);
   });
 
   it('returns empty array when dir empty', () => {
     const vol = create({});
     const dirs = vol.readdirSync('/');
 
-    expect(dirs).toEqual([]);
+    expect(dirs).toEqual(['.', '..']);
   });
 
   it('respects symlinks', () => {
@@ -43,7 +43,7 @@ describe('readdirSync()', () => {
 
     (dirs as any).sort();
 
-    expect(dirs).toEqual(['a', 'aa']);
+    expect(dirs).toEqual(['.', '..', 'a', 'aa']);
   });
 
   it('respects recursive symlinks', () => {
@@ -53,6 +53,6 @@ describe('readdirSync()', () => {
 
     const dirs = vol.readdirSync('/foo');
 
-    expect(dirs).toEqual(['foo']);
+    expect(dirs).toEqual(['.', '..', 'foo']);
   });
 });

src/node.ts

@@ -44,9 +44,21 @@ export class Node extends EventEmitter {
     this.perm = perm;
     this.mode |= perm;
     this.ino = ino;
+
+    return new Proxy(this, {
+      set(target, name, value): boolean {
+        const metadataProps = ['uid', 'gid', 'atime', 'mtime', 'perm', 'nlink'];
+        if (metadataProps.includes(String(name))) {
+          target.ctime = new Date();
+        }
+        target[name] = value;
+        return true;
+      },
+    });
   }
 
   getString(encoding = 'utf8'): string {
+    this.atime = new Date();
     return this.getBuffer().toString(encoding);
   }
 
@@ -57,6 +69,7 @@ export class Node extends EventEmitter {
   }
 
   getBuffer(): Buffer {
+    this.atime = new Date();
     if (!this.buf) this.setBuffer(bufferAllocUnsafe(0));
     return bufferFrom(this.buf); // Return a copy.
   }
@@ -122,6 +135,7 @@ export class Node extends EventEmitter {
 
   // Returns the number of bytes read.
   read(buf: Buffer | Uint8Array, off: number = 0, len: number = buf.byteLength, pos: number = 0): number {
+    this.atime = new Date();
     if (!this.buf) this.buf = bufferAllocUnsafe(0);
 
     let actualLen = len;
@@ -262,8 +276,11 @@ export class Link extends EventEmitter {
   // Recursively sync children steps, e.g. in case of dir rename
   set steps(val) {
     this._steps = val;
-    for (const child of Object.values(this.children)) {
-      child?.syncSteps();
+    for (const [child, link] of Object.entries(this.children)) {
+      if (child === '.' || child === '..') {
+        continue;
+      }
+      link?.syncSteps();
     }
   }
 
@@ -289,10 +306,8 @@ export class Link extends EventEmitter {
     link.setNode(node);
 
     if (node.isDirectory()) {
-      // link.setChild('.', link);
-      // link.getNode().nlink++;
-      // link.setChild('..', this);
-      // this.getNode().nlink++;
+      link.children['.'] = link;
+      link.getNode().nlink++;
     }
 
     this.setChild(name, link);
@@ -305,19 +320,33 @@ export class Link extends EventEmitter {
     link.parent = this;
     this.length++;
 
+    const node = link.getNode();
+    if (node.isDirectory()) {
+      link.children['..'] = this;
+      this.getNode().nlink++;
+      this.getNode().mtime = new Date();
+    }
+
     this.emit('child:add', link, this);
 
     return link;
   }
 
   deleteChild(link: Link) {
+    const node = link.getNode();
+    if (node.isDirectory()) {
+      delete link.children['..'];
+      this.getNode().nlink--;
+      this.getNode().mtime = new Date();
+    }
     delete this.children[link.getName()];
     this.length--;
 
     this.emit('child:delete', link, this);
   }
 
   getChild(name: string): Link | undefined {
+    this.getNode().mtime = new Date();
     if (Object.hasOwnProperty.call(this.children, name)) {
       return this.children[name];
     }

src/volume.ts

@@ -666,11 +666,11 @@ export class Volume {
       }
     };
 
-    // root.setChild('.', root);
-    // root.getNode().nlink++;
+    root.setChild('.', root);
+    root.getNode().nlink++;
 
-    // root.setChild('..', root);
-    // root.getNode().nlink++;
+    root.setChild('..', root);
+    root.getNode().nlink++;
 
     this.root = root;
   }
@@ -879,6 +879,9 @@ export class Volume {
     }
 
     for (const name in children) {
+      if (name === '.' || name === '..') {
+        continue;
+      }
       isEmpty = false;
 
       const child = link.getChild(name);