learn-request-queue/src/version.ts

import * as queries from "./queries";
import { log, LogLevel } from "./logging"
import express from "express";
import pg from "pg";
import db from "./db";

var versionMajor = 0;
var versionMinor = 6;
var versionPatch = 0;

export function getVersion() {
	return `${versionMajor}.${versionMinor}.${versionPatch}`
}

export async function checkVersionMiddleware(_req: express.Request, _res: express.Response, next: express.NextFunction) {
	try {
		await checkVersion();
	} catch (e) {
		log(LogLevel.ERROR,e)
		// Terminate the nodejs process with error. If restarted, the app will
		// never start listening for new requests so this will not result in a
		// restart loop.
		process.exit(1);
	}
	next();
}

export async function checkVersion() {
	var dbver = await db.query(queries.getDbVersion).then((result: pg.QueryResult) => result.rows[0]['get_version']);
	if (dbver != `${versionMajor}.${versionMinor}`) {
		throw new Error("Version mismatch!\nApplication version: " + getVersion() + "\nDatabase version: " + dbver)
	}
}