omniwheel/dist/server-promises.js

Boilerplate reduction for backend and microservices. Scale your application easily in any direction.

/**
 * Invoke the object's callback-based listen() method, returning a Promise to the created server.
 * The Promise is resolved only as soon as the server is listening, as indicated by its 'listening' event.
 *
 * This function can be used to start Express applications, but also regular http.Server instances etc.,
 * as long as they have a compatible listen() method.
 *
 * @param app The application to start.
 * @param port The port to listen on.
 * @param hostname The hostname to listen on.
 * @returns A Promise that resolves to the started server.
 */
export async function promisifiedListen(app, port, hostname) {
    return await new Promise((resolve, reject) => {
        const httpServer = hostname != null ? app.listen(port, hostname) : app.listen(port);
        httpServer.once('listening', () => resolve(httpServer));
        httpServer.once('error', reject);
    });
}
/**
 * Invoke the object's callback-based close() method, returning a Promise.
 *
 * This is intended to stop http.Server instances but can be used for anything with a compatible close() method.
 *
 * @param server The server to close.
 * @returns A Promise that resolves when done.
 */
export async function promisifiedClose(server) {
    await new Promise((resolve, reject) => server.close((err) => {
        if (err != null) {
            reject(err);
        }
        else {
            resolve();
        }
    }));
}