feat: 🎸 implement toTreeSync() method

src/print/__tests__/index.test.ts

@@ -0,0 +1,50 @@
+import { toTreeSync } from '..';
+import { memfs } from '../..';
+
+test('can print a single file', () => {
+  const { fs } = memfs({
+    '/file.txt': '...',
+  });
+  expect(toTreeSync(fs, { dir: '/' })).toMatchInlineSnapshot(`
+    "/
+    └─ file.txt"
+  `);
+});
+
+test('can a one level deep directory tree', () => {
+  const { fs } = memfs({
+    '/file.txt': '...',
+    '/foo/bar.txt': '...',
+    '/foo/index.php': '...',
+  });
+  expect(toTreeSync(fs, { dir: '/' })).toMatchInlineSnapshot(`
+    "/
+    ├─ file.txt
+    └─ foo/
+       ├─ bar.txt
+       └─ index.php"
+  `);
+});
+
+test('can print two-levels of folders', () => {
+  const { fs } = memfs({
+    '/level1/level2/file.txt': '...',
+  });
+  expect(toTreeSync(fs, { dir: '/' })).toMatchInlineSnapshot(`
+    "/
+    └─ level1/
+       └─ level2/
+          └─ file.txt"
+  `);
+});
+
+test('can stop recursion at specified depth', () => {
+  const { fs } = memfs({
+    '/dir1/dir2/dir3/file.txt': '...',
+  });
+  expect(toTreeSync(fs, { dir: '/', depth: 2 })).toMatchInlineSnapshot(`
+    "/
+    └─ dir1/
+       └─ dir2/ (...)"
+  `);
+});

src/print/index.ts

@@ -0,0 +1,35 @@
+import {printTree} from 'json-joy/es6/util/print/printTree';
+import {basename} from "../node-to-fsa/util";
+import type {FsSynchronousApi} from "../node/types";
+import type {IDirent} from "../node/types/misc";
+
+export const toTreeSync = (fs: FsSynchronousApi, opts: ToTreeOptions = {}) => {
+  const separator = opts.separator || '/';
+  let dir = opts.dir || separator;
+  if (dir[dir.length - 1] !== separator) dir += separator;
+  const tab = opts.tab || '';
+  const depth = opts.depth ?? 10;
+  let subtree = ' (...)';
+  if (depth > 0) {
+    const list = fs.readdirSync(dir, {withFileTypes: true}) as IDirent[];
+    subtree = printTree(tab, list.map(
+      (entry) => (tab) => {
+        const isDir = entry.isDirectory();
+        if (isDir) {
+          return toTreeSync(fs, {dir: dir + entry.name, depth: depth - 1, tab});
+        } else {
+          return '' + entry.name;
+        }
+      },
+    ))
+  }
+  const base = basename(dir, separator) + separator;
+  return base + subtree;
+};
+
+export interface ToTreeOptions {
+  dir?: string;
+  tab?: string;
+  depth?: number;
+  separator?: '/' | '\\';
+}

src/volume.ts

@@ -1880,6 +1880,7 @@ export class Volume implements FsCallbackApi {
   public statfsSync: FsSynchronousApi['statfsSync'] = notImplemented;
   public writevSync: FsSynchronousApi['writevSync'] = notImplemented;
   public readvSync: FsSynchronousApi['readvSync'] = notImplemented;
+  public opendirSync: FsSynchronousApi['opendirSync'] = notImplemented;
 
   public cp: FsCallbackApi['cp'] = notImplemented;
   public lutimes: FsCallbackApi['lutimes'] = notImplemented;