Are .server.ts fetch dependencies tracked?

[pjeziorowski]

Quick question: Will calling invalidate(myBackendEndpoint) on the client side invalidate or rerun a backend (.server.ts) load function that uses SvelteKit's fetch to get data from myBackendEndpoint?

I've noticed that invalidate(myBackendEndpoint) works well when I load data in +page.ts, but it doesn't seem to invalidate when the data loading is moved to +page.server.ts. I also noticed that this server loader isn't dependent on any URL, even though it makes a fetch call to myBackendEndpoint 🤔

Is this the expected behavior? I looked for more information in the documentation, but it doesn't seem to be explicitly covered there.

[eltigerchino]

I did some digging and it is documented (albeit we could do better) https://svelte.dev/docs/kit/load#Rerunning-load-functions-Manual-invalidation

Server load functions will never automatically depend on a fetched url to avoid leaking secrets to the client.

This probably makes sense since a server fetch could have some sensitive information in the URL if it's making a request to a private endpoint.

Fortunately, you explicitly track it using the depends function which is passed to https://svelte.dev/docs/kit/@sveltejs-kit#LoadEvent (scroll down a little to find the description).

This function declares that the load function has a dependency on one or more URLs or custom identifiers, which can subsequently be used with invalidate() to cause load to rerun.

[eltigerchino]

I've created a new issue for this here #13805