@mark01/express-utils/lib/server/express.js

npm package that contains utilities for express.js

export class Server {
    expressApp;
    listenPort;
    infrastructureCheck;
    extraStartupChecks;
    constructor(options) {
        this.expressApp = options.app;
        this.listenPort = options.port;
        this.infrastructureCheck = options.onInfrastructureCheck;
        this.extraStartupChecks = options.onExtraChecks;
    }
    async start() {
        this.setupUncaughtExceptionHandling();
        if (this.infrastructureCheck) {
            const status = await this.infrastructureCheck();
            console.log(`Infrastructure status: ${JSON.stringify(status)}.`);
        }
        if (this.extraStartupChecks) {
            await this.extraStartupChecks();
            console.log('All additional startup checks passed!');
        }
        const httpServer = this.expressApp.listen(this.listenPort, () => {
            console.log(`API is running on port ${this.listenPort} in ${process.env.NODE_ENV} mode!`);
        });
        this.setupGracefulShutdown(httpServer);
    }
    setupUncaughtExceptionHandling() {
        process.on('uncaughtException', (error) => {
            console.error('Unhandled exception 💥! Shutting down the application.');
            console.error(`Error name: ${error.name}, message: ${error.message}`);
            process.exit(1);
        });
    }
    setupGracefulShutdown(httpServer) {
        const shutdownHandler = (reason, exitCode) => {
            console.log(`Initiating server shutdown due to ${reason}`);
            httpServer.close(() => {
                console.log('Closed all active connections.');
                process.exit(exitCode);
            });
        };
        process.on('unhandledRejection', (error) => {
            console.error('Unhandled promise rejection 💥! Shutting down the application.');
            console.error(`Error name: ${error.name}, message: ${error.message}`);
            shutdownHandler('unhandledRejection', 1);
        });
        process.on('SIGINT', () => shutdownHandler('SIGINT', 0));
        process.on('SIGQUIT', () => shutdownHandler('SIGQUIT', 0));
        process.on('SIGTERM', () => shutdownHandler('SIGTERM', 0));
    }
}