BREAKING CHANGE(smartwatch): Introduce Smartwatch: cross-runtime native file watching for Node.js, Deno and Bun; rename smartchok to smartwatch and bump major version to 2.0.0

This commit is contained in:
2025-11-30 03:04:49 +00:00
parent aab3ce213b
commit 0f17be179c
16 changed files with 1011 additions and 162 deletions

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ts/watchers/watcher.node.ts Normal file
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import * as fs from 'fs';
import * as path from 'path';
import * as smartrx from '@push.rocks/smartrx';
import type { IWatcher, IWatcherOptions, IWatchEvent, TWatchEventType } from './interfaces.js';
import { WriteStabilizer } from '../utils/write-stabilizer.js';
/**
* Node.js/Bun file watcher using native fs.watch API
*/
export class NodeWatcher implements IWatcher {
private watchers: Map<string, fs.FSWatcher> = new Map();
private watchedFiles: Set<string> = new Set();
private _isWatching = false;
private writeStabilizer: WriteStabilizer;
private recentEvents: Map<string, number> = new Map();
private throttleMs = 50;
public readonly events$ = new smartrx.rxjs.Subject<IWatchEvent>();
constructor(private options: IWatcherOptions) {
this.writeStabilizer = new WriteStabilizer(
options.stabilityThreshold,
options.pollInterval
);
}
get isWatching(): boolean {
return this._isWatching;
}
async start(): Promise<void> {
if (this._isWatching) {
return;
}
try {
// Start watching each base path
for (const basePath of this.options.basePaths) {
await this.watchPath(basePath, 0);
}
this._isWatching = true;
// Perform initial scan to emit 'add' events for existing files
for (const basePath of this.options.basePaths) {
await this.scanDirectory(basePath, 0);
}
// Emit ready event
this.events$.next({ type: 'ready', path: '' });
} catch (error: any) {
this.events$.next({ type: 'error', path: '', error });
throw error;
}
}
async stop(): Promise<void> {
this._isWatching = false;
this.writeStabilizer.cancelAll();
// Close all watchers
for (const [watchPath, watcher] of this.watchers) {
watcher.close();
}
this.watchers.clear();
this.watchedFiles.clear();
this.recentEvents.clear();
}
/**
* Start watching a path (file or directory)
*/
private async watchPath(watchPath: string, depth: number): Promise<void> {
if (depth > this.options.depth) {
return;
}
try {
const stats = await this.statSafe(watchPath);
if (!stats) {
return;
}
if (stats.isDirectory()) {
// Watch the directory with recursive option (Node.js 20+ supports this on all platforms)
const watcher = fs.watch(
watchPath,
{ recursive: true, persistent: true },
(eventType, filename) => {
if (filename) {
this.handleFsEvent(watchPath, filename, eventType);
}
}
);
watcher.on('error', (error) => {
this.events$.next({ type: 'error', path: watchPath, error });
});
this.watchers.set(watchPath, watcher);
}
} catch (error: any) {
this.events$.next({ type: 'error', path: watchPath, error });
}
}
/**
* Handle raw fs.watch events and normalize them
*/
private async handleFsEvent(
basePath: string,
filename: string,
eventType: 'rename' | 'change' | string
): Promise<void> {
const fullPath = path.join(basePath, filename);
// Throttle duplicate events
if (!this.shouldEmit(fullPath, eventType)) {
return;
}
try {
const stats = await this.statSafe(fullPath);
if (eventType === 'rename') {
// 'rename' can mean add or unlink - check if file exists
if (stats) {
// File exists - it's either a new file or was renamed to this location
if (stats.isDirectory()) {
if (!this.watchedFiles.has(fullPath)) {
this.watchedFiles.add(fullPath);
this.events$.next({ type: 'addDir', path: fullPath, stats });
}
} else {
// Wait for write to stabilize before emitting
try {
const stableStats = await this.writeStabilizer.waitForWriteFinish(fullPath);
const wasWatched = this.watchedFiles.has(fullPath);
this.watchedFiles.add(fullPath);
this.events$.next({
type: wasWatched ? 'change' : 'add',
path: fullPath,
stats: stableStats
});
} catch {
// File was deleted during stabilization
if (this.watchedFiles.has(fullPath)) {
this.watchedFiles.delete(fullPath);
this.events$.next({ type: 'unlink', path: fullPath });
}
}
}
} else {
// File doesn't exist - it was deleted
if (this.watchedFiles.has(fullPath)) {
const wasDir = this.isKnownDirectory(fullPath);
this.watchedFiles.delete(fullPath);
this.events$.next({
type: wasDir ? 'unlinkDir' : 'unlink',
path: fullPath
});
}
}
} else if (eventType === 'change') {
// File was modified
if (stats && !stats.isDirectory()) {
try {
const stableStats = await this.writeStabilizer.waitForWriteFinish(fullPath);
// Check if this is a new file (not yet in watchedFiles)
const wasWatched = this.watchedFiles.has(fullPath);
if (!wasWatched) {
// This is actually an 'add' - file wasn't being watched before
this.watchedFiles.add(fullPath);
this.events$.next({ type: 'add', path: fullPath, stats: stableStats });
} else {
this.events$.next({ type: 'change', path: fullPath, stats: stableStats });
}
} catch {
// File was deleted during write
if (this.watchedFiles.has(fullPath)) {
this.watchedFiles.delete(fullPath);
this.events$.next({ type: 'unlink', path: fullPath });
}
}
}
}
} catch (error: any) {
this.events$.next({ type: 'error', path: fullPath, error });
}
}
/**
* Scan directory and emit 'add' events for existing files
*/
private async scanDirectory(dirPath: string, depth: number): Promise<void> {
if (depth > this.options.depth) {
return;
}
try {
const entries = await fs.promises.readdir(dirPath, { withFileTypes: true });
for (const entry of entries) {
const fullPath = path.join(dirPath, entry.name);
const stats = await this.statSafe(fullPath);
if (!stats) {
continue;
}
if (entry.isDirectory()) {
this.watchedFiles.add(fullPath);
this.events$.next({ type: 'addDir', path: fullPath, stats });
await this.scanDirectory(fullPath, depth + 1);
} else if (entry.isFile()) {
this.watchedFiles.add(fullPath);
this.events$.next({ type: 'add', path: fullPath, stats });
}
}
} catch (error: any) {
if (error.code !== 'ENOENT' && error.code !== 'EACCES') {
this.events$.next({ type: 'error', path: dirPath, error });
}
}
}
/**
* Safely stat a path, returning null if it doesn't exist
*/
private async statSafe(filePath: string): Promise<fs.Stats | null> {
try {
if (this.options.followSymlinks) {
return await fs.promises.stat(filePath);
} else {
return await fs.promises.lstat(filePath);
}
} catch {
return null;
}
}
/**
* Check if a path was known to be a directory (for proper unlink event type)
*/
private isKnownDirectory(filePath: string): boolean {
// Check if any watched files are children of this path
for (const watched of this.watchedFiles) {
if (watched.startsWith(filePath + path.sep)) {
return true;
}
}
return false;
}
/**
* Throttle duplicate events
*/
private shouldEmit(filePath: string, eventType: string): boolean {
const key = `${filePath}:${eventType}`;
const now = Date.now();
const lastEmit = this.recentEvents.get(key);
if (lastEmit && now - lastEmit < this.throttleMs) {
return false;
}
this.recentEvents.set(key, now);
// Clean up old entries periodically
if (this.recentEvents.size > 1000) {
const cutoff = now - this.throttleMs * 2;
for (const [k, time] of this.recentEvents) {
if (time < cutoff) {
this.recentEvents.delete(k);
}
}
}
return true;
}
}