feat: 🎸 add promises.watch() implementation

package.json

@@ -23,9 +23,13 @@
     "url": "https://github.com/streamich/memfs.git"
   },
   "dependencies": {
+    "callback-to-async-iterator": "^1.1.1",
     "fs-monkey": "1.0.3"
   },
   "devDependencies": {
+    "@semantic-release/changelog": "5.0.1",
+    "@semantic-release/git": "9.0.1",
+    "@semantic-release/npm": "8.0.0",
     "@types/jest": "27.0.1",
     "@types/node": "10.17.60",
     "cpy-cli": "3.1.1",
@@ -34,15 +38,12 @@
     "prettier": "2.4.1",
     "pretty-quick": "3.1.1",
     "rimraf": "3.0.2",
+    "semantic-release": "18.0.0",
     "ts-jest": "27.0.5",
     "ts-node": "10.2.1",
     "tslint": "5.20.1",
     "tslint-config-common": "1.6.0",
-    "typescript": "4.4.3",
-    "semantic-release": "18.0.0",
-    "@semantic-release/changelog": "5.0.1",
-    "@semantic-release/git": "9.0.1",
-    "@semantic-release/npm": "8.0.0"
+    "typescript": "4.4.3"
   },
   "config": {
     "commitizen": {

src/__tests__/util.ts

@@ -1,7 +1,7 @@
 import { createFsFromVolume, Volume } from '..';
 import { Link, Node } from '../node';
 
-export const create = (json: { [s: string]: string } = { '/foo': 'bar' }) => {
+export const create = (json: { [s: string]: string | null } = { '/foo': 'bar' }) => {
   const vol = Volume.fromJSON(json);
   return vol;
 };

src/__tests__/volume/watchPromise.test.ts

@@ -0,0 +1,10 @@
+import { create } from '../util';
+
+describe('promises.watch(path, options)', () => {
+  it('emits filesystem events', async () => {
+    const vol = create({foo: 'a'});
+    // const iterator = vol.promises.watch('/foo', {});
+
+    // console.log(iterator);
+  });
+});

src/promises.ts

@@ -14,11 +14,13 @@ import {
   IWriteFileOptions,
   IStatOptions,
   IRmOptions,
+  IWatchOptions,
 } from './volume';
 import Stats from './Stats';
 import Dirent from './Dirent';
 import { TDataOut } from './encoding';
 import { PathLike, symlink } from 'fs';
+import asyncify from 'callback-to-async-iterator';
 
 function promisify(
   vol: Volume,
@@ -94,6 +96,7 @@ export interface IPromisesAPI {
   unlink(path: PathLike): Promise<void>;
   utimes(path: PathLike, atime: TTime, mtime: TTime): Promise<void>;
   writeFile(id: TFileHandle, data: TData, options?: IWriteFileOptions): Promise<void>;
+  watch(path: PathLike, options?: string | IWatchOptions): AsyncIterator<{eventType: string, filename: string | Buffer}>;
 }
 
 export class FileHandle implements IFileHandle {
@@ -274,5 +277,13 @@ export default function createPromisesApi(vol: Volume): null | IPromisesAPI {
     writeFile(id: TFileHandle, data: TData, options?: IWriteFileOptions): Promise<void> {
       return promisify(vol, 'writeFile')(id instanceof FileHandle ? id.fd : (id as PathLike), data, options);
     },
+
+    watch(path: PathLike, options?: string | IWatchOptions): AsyncIterator<{eventType: string, filename: string | Buffer}> {
+      return asyncify((callback) => {
+        vol.watch(path, options || 'utf8', (eventType, filename) => {
+          callback({eventType, filename});
+        });
+      });
+    }
   };
 }

src/volume.ts

@@ -2193,11 +2193,11 @@ export class Volume {
     return new this.WriteStream(path, options);
   }
 
-  // watch(path: PathLike): FSWatcher;
-  // watch(path: PathLike, options?: IWatchOptions | string): FSWatcher;
+  watch(path: PathLike, listener: (eventType: string, filename: string) => void): FSWatcher;
+  watch(path: PathLike, options: IWatchOptions | string, listener: (eventType: string, filename: string) => void): FSWatcher;
   watch(
     path: PathLike,
-    options?: IWatchOptions | string,
+    options: (IWatchOptions | string) | ((eventType: string, filename: string) => void),
     listener?: (eventType: string, filename: string) => void,
   ): FSWatcher {
     const filename = pathToFilename(path);

yarn.lock

@@ -1945,6 +1945,13 @@ call-me-maybe@^1.0.1:
   resolved "https://registry.yarnpkg.com/call-me-maybe/-/call-me-maybe-1.0.1.tgz#26d208ea89e37b5cbde60250a15f031c16a4d66b"
   integrity sha1-JtII6onje1y95gJQoV8DHBak1ms=
 
+callback-to-async-iterator@^1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/callback-to-async-iterator/-/callback-to-async-iterator-1.1.1.tgz#110adcde834589bee475415baf0123b6a541c398"
+  integrity sha512-w5uOapjkp/CEizuvBkLl7JyHlQNlxAT7LSr9g4vFjg5AEM5TJvaajjKkgs4kcFFm0fNqFX9D0zEIotllXvNC1Q==
+  dependencies:
+    iterall "^1.0.0"
+
 callsites@^3.0.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/callsites/-/callsites-3.1.0.tgz#b3630abd8943432f54b3f0519238e33cd7df2f73"
@@ -3732,6 +3739,11 @@ istanbul-reports@^3.0.2:
     html-escaper "^2.0.0"
     istanbul-lib-report "^3.0.0"
 
+iterall@^1.0.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/iterall/-/iterall-1.3.0.tgz#afcb08492e2915cbd8a0884eb93a8c94d0d72fea"
+  integrity sha512-QZ9qOMdF+QLHxy1QIpUHUU1D5pS2CG2P69LF6L6CPjPYA/XMOmKV3PZpawHoAjHNyB0swdVTRxdYT4tbBbxqwg==
+
 java-properties@^1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/java-properties/-/java-properties-1.0.2.tgz#ccd1fa73907438a5b5c38982269d0e771fe78211"