init doesn't work as intended in production

[aym-i]

Solution here

Describe the bug

Hi,
Using init in a hooks.client.ts file would work as intended but not in production (Vercel in my case)

Reproduction

• Create a hooks.client.ts with init that does some logic
• Make sure the logic works in development environment
• Host the project in Vercel
• Check if the logic is working

Logs

System Info

System:
    OS: Windows 10 10.0.19045
  Binaries:
    Node: 20.9.0 - C:\Program Files\nodejs\node.EXE
  npmPackages:
    @sveltejs/adapter-auto: ^3.3.1 => 3.3.1
    @sveltejs/adapter-vercel: ^5.4.6 => 5.5.3
    @sveltejs/kit: ^2.7.3 => 2.16.0
    @sveltejs/vite-plugin-svelte: 4.0.0 => 4.0.0
    svelte: ^5.1.2 => 5.19.0
    vite: ^5.0.0 => 5.4.11

Severity

serious, but I can work around it

Additional Information

According to the docs:

This function runs once, when the server is created or the app starts in the browser, and is a useful place to do asynchronous work such as initializing a database connection.

Does this mean that the init function in a vercel instance runs ONLY when the server has started? But what about the second part of the statement? Am I misunderstanding the docs here?

[paoloricciuti]

There are really two init hooks...the client init hook which you are using runs once when the application start on the client (basically on every hard refresh).

The server one runs once every time the server starts the sveltekit application. In case of server less tho everytime your server less function goes to sleep is just like if the server shut down and with a new request it needs to spin up again (and the init hook will and need to rerun to re initialize everything)

[aym-i]

There are really two init hooks...the client init hook which you are using runs once when the application start on the client (basically on every hard refresh).

The server one runs once every time the server starts the sveltekit application. In case of server less tho everytime your server less function goes to sleep is just like if the server shut down and with a new request it needs to spin up again (and the init hook will and need to rerun to re initialize everything)

@paoloricciuti Hi thanks for the reply, but in my case the code inside the init hook doesn't even run

[elliott-with-the-longest-name-on-github]

@retr0cube please provide a repro of your problem:

• npx sv create my-repro
• git init && git add --all && git commit -m "Initial commit"
• Add the code that minimally illustrates your issue
• git add --all && git commit -m "Reproduce issue"
• Create a repository on GutHub and upload your code
• Share the link here

We get a lot of issues, so being able to pull your code and deploy it rather than faff about talking to you and trying to figure out what the issue is by ourselves makes it a lot more likely we can get a fix out quickly 😉

[aym-i]

@retr0cube please provide a repro of your problem:

• npx sv create my-repro
• git init && git add --all && git commit -m "Initial commit"
• Add the code that minimally illustrates your issue
• git add --all && git commit -m "Reproduce issue"
• Create a repository on GutHub and upload your code
• Share the link here

We get a lot of issues, so being able to pull your code and deploy it rather than faff about talking to you and trying to figure out what the issue is by ourselves makes it a lot more likely we can get a fix out quickly 😉

This repo has the exact code I have in my repo:
https://stackblitz.com/edit/sveltejs-kit-template-default-qeogrnwf?file=src%2Froutes%2Fhooks.client.ts

As you can see it works in dev but hosting this in for example Vercel will not work :/

[aym-i]

There are really two init hooks...the client init hook which you are using runs once when the application start on the client (basically on every hard refresh).

The server one runs once every time the server starts the sveltekit application. In case of server less tho everytime your server less function goes to sleep is just like if the server shut down and with a new request it needs to spin up again (and the init hook will and need to rerun to re initialize everything)

Yes, I got you but the client init doesn't work on prod as opposed to dev

[paoloricciuti]

This is your code deployed to vercel...it seem to work fine

https://test-init-hook-repo.vercel.app/

[aym-i]

This is your code deployed to vercel...it seem to work fine

https://test-init-hook-repo.vercel.app/

That exact same setup doesn't work here (same code as there)

[paoloricciuti]

This is your code deployed to vercel...it seem to work fine
https://test-init-hook-repo.vercel.app/

That exact same setup doesn't work here (same code as there)

If it's not working it's clearly not the same setup. Please provide an actual failing reproduction so we can take a look

[aym-i]

This is your code deployed to vercel...it seem to work fine
https://test-init-hook-repo.vercel.app/

That exact same setup doesn't work here (same code as there)

If it's not working it's clearly not the same setup. Please provide an actual failing reproduction so we can take a look

Here.

[paoloricciuti]

This is not a minimal reproduction, is your whole code...however I did forked your repo and deployed it to vercel and as you can see here it works

[paoloricciuti]

However I had to make some changes to not use supabase and such...please provide a minimal reproduction that actually doesn't work

[aym-i]

However I had to make some changes to not use supabase and such...please provide a minimal reproduction that actually doesn't work

I did send you my deployment and it doesn't work, yet yours does?

NB: your url is private I need team access

[paoloricciuti]

However I had to make some changes to not use supabase and such...please provide a minimal reproduction that actually doesn't work

I did send you my deployment and it doesn't work, yet yours does?

NB: your url is private I need team access

Should be working now...yes it works

[aym-i]

However I had to make some changes to not use supabase and such...please provide a minimal reproduction that actually doesn't work

I did send you my deployment and it doesn't work, yet yours does?
NB: your url is private I need team access

Should be working now...yes it works

Hey, I can confirm it works on my end, but in my website no

(with all cookies cleared)

You can see that your deployment (left) created the theme attribute but not mine (right), this may have to do with my deployment settings but I doubt it.