Executing custom code

All JavaScript code is executed by the main thread, which means that any operation that doesn’t use the non-blocking API provided by Node.js will block the thread. For the sake of consistency, add the statement shown in Listing 4.18 to the promises.ts file to wrap the write method defined by the ServerResponse class in a promise.

Listing 4.18: Adding a Function in the promises.ts File in the src Folder

import { ServerResponse } from "http";
import { promisify } from "util";
export const endPromise = promisify(ServerResponse.prototype.end) as
    (data: any) => Promise<void>;
export const writePromise = promisify(ServerResponse.prototype.write) as
    (data: any) => Promise<void>;

Listing 4.19 filters out the requests for the favicon.ico file, which was fine in earlier examples, but will add unwanted requests in this section.

Listing 4.19: Filtering Requests in the server.ts File in the src Folder

...