How to run server code before server start in framework mode?

[GabenGar]

I want to load and validate config from a file plus run some database stuff, aka async logic, and only run the rest of the server if both steps didn't throw.
Not sure where to put it though, the template has 3 "spots" to put:

• server.js
  I don't see the point of this file, plus it's not transpiled in the first place, which makes aforementioned procedures harder to use since they are written in typescript and are used in the code of the runtime server.

• server/app.ts
  This one sounded like a proper place, but it doesn't allow top level await which makes "validate, parse and continue" flow impossible. Plus it has a strange structure where symbols in this file are dynamically imported in server.js with no type hints, thus forcing to coordinate two parts for the same thing. And if I am going to have actual modules in here I have to make sure they aren't getting imported by the "main" code, since this path is not subject to .server modules static analysis.

• hidden app/entry.server.tsx
  Pretty sure this one is called on each request, so out of the picture for my situation.

[sergiodxa]

You need to do it in your HTTP server (server/app.ts would be the best place)

You could do it in entry.server at the module level (outside the exported function) but your RR app may not be imported by the server until a first request run, and in development it will be re-imported on every change.

[GabenGar]

server/app.ts runs on each request and in fact doesn't run until first request, which makes sense because that's what it literally does in the example.
Does it mean there is no way to run some async logic prior server startup without introducing another build step just for that?

[sergiodxa]

In that case your will have to do it inside that server.js file.

[sudo-vaibhav]

well @GabenGar cant you write an idempotent thing to make sure only once execution (sure its still just in time though)

  class InitialOperations {
    static done = false;

    constructor() { }
    static async idempotentExecute() {
      console.log("InitialOperations.idempotentExecute started");
      if (!InitialOperations.done) {
      	await runMigrations(db);
      	await seedDatabase(db);
      }
      InitialOperations.done = true;
      console.log("InitialOperations.idempotentExecute finished");
    }
  }

  await InitialOperations.idempotentExecute();

[valenterry]

I want do know that too. It's crazy that there is no standard and well documented way to do this. It's absolutely required for any app that is more than a toy app imho.

[sudo-vaibhav]

i tried both the root loader and the entry.server.tsx, but some loader always fetches before them (i guess thats to deal with the waterfall problem)

but this makes it impossible to do on start db migrations and other similar problems

[sergiodxa]

Loaders run in parallel, and all of them before entry.server