Notes/apps/server/src/etapi/spec.ts

import type { Router } from "express";

import fs from "fs";
import path from "path";

import { fileURLToPath } from "url";
const specPath = path.join(path.dirname(fileURLToPath(import.meta.url)), "etapi.openapi.yaml");
let spec: string | null = null;

function register(router: Router) {
    router.get("/etapi/etapi.openapi.yaml", (req, res, next) => {
        if (!spec) {
            spec = fs.readFileSync(specPath, "utf8");
        }

        res.header("Content-Type", "text/plain"); // so that it displays in browser
        res.status(200).send(spec);
    });
}

export default {
    register
};