/**
* Development Mode Features
*
* Implements hot reload and development-time features for enhanced MCP server development.
* These features are only active when FOLDER_MCP_DEVELOPMENT_ENABLED=true.
*/
import { watch } from 'chokidar';
import type { EnhancedMCPConfig } from './enhanced-mcp.js';
import type { ILoggingService } from '../di/interfaces.js';
export interface DevModeManager {
startWatching(): Promise<void>;
stopWatching(): Promise<void>;
isWatching(): boolean;
}
export class DevModeManager implements DevModeManager {
private watcher: any = null;
private restartCallback: (() => void) | null = null;
constructor(
private readonly config: EnhancedMCPConfig,
private readonly logger: ILoggingService,
restartCallback?: () => void
) {
this.restartCallback = restartCallback || null;
}
async startWatching(): Promise<void> {
if (!this.config.dev?.watch || !this.config.dev?.hotReload) {
this.logger.info('Development mode disabled or hot reload not configured');
return;
}
if (this.watcher) {
this.logger.info('File watcher already running');
return;
}
const watchPattern = this.config.dev.watch;
this.logger.info('Starting development mode file watcher', { pattern: watchPattern });
try {
this.watcher = watch(watchPattern, {
ignoreInitial: true,
persistent: true,
});
this.watcher.on('change', (path: string) => {
this.logger.info('File changed - triggering hot reload', { path });
this.handleFileChange(path);
});
this.watcher.on('add', (path: string) => {
this.logger.info('File added - triggering hot reload', { path });
this.handleFileChange(path);
});
this.watcher.on('unlink', (path: string) => {
this.logger.info('File removed - triggering hot reload', { path });
this.handleFileChange(path);
});
this.watcher.on('error', (error: Error) => {
this.logger.error('File watcher error', error);
});
this.logger.info('Development mode file watcher started successfully', {
pattern: watchPattern,
hotReload: this.config.dev.hotReload
});
} catch (error) {
this.logger.error('Failed to start development mode file watcher', error instanceof Error ? error : new Error(String(error)));
throw error;
}
}
async stopWatching(): Promise<void> {
if (this.watcher) {
this.logger.info('Stopping development mode file watcher');
await this.watcher.close();
this.watcher = null;
this.logger.info('Development mode file watcher stopped');
}
}
isWatching(): boolean {
return this.watcher !== null;
}
private handleFileChange(path: string): void {
this.logger.info('🔥 Hot reload triggered', { changedFile: path });
if (this.restartCallback) {
// Debounce rapid file changes
setTimeout(() => {
if (this.restartCallback) {
this.logger.info('🚀 Restarting MCP server due to file changes');
this.restartCallback();
}
}, 500);
} else {
this.logger.warn('Hot reload triggered but no restart callback configured');
}
}
}
/**
* Initialize development mode features if enabled
*/
export async function initializeDevMode(
config: EnhancedMCPConfig | null,
logger: ILoggingService,
restartCallback?: () => void
): Promise<DevModeManager | null> {
if (!config?.dev?.hotReload) {
logger.info('Development mode not enabled');
return null;
}
logger.info('Initializing development mode features', {
watch: config.dev.watch,
debug: config.dev.debug,
hotReload: config.dev.hotReload,
autoRestart: config.dev.autoRestart
});
const devManager = new DevModeManager(config, logger, restartCallback);
await devManager.startWatching();
return devManager;
}
/**
* Get debug configuration for development mode
*/
export function getDebugConfig(config: EnhancedMCPConfig): any {
if (!config.dev?.debug?.enabled) {
return null;
}
return {
type: config.dev.debug.type || 'node',
port: config.dev.debug.port || 9229,
enabled: config.dev.debug.enabled
};
}
/**
* Check if development mode features should be enabled
*/
export function shouldEnableDevMode(): boolean {
return process.env.FOLDER_MCP_DEVELOPMENT_ENABLED === 'true' ||
process.env.NODE_ENV === 'development';
}
