Wouldn't this set context to undefined initially? And reassigning a new value to client wouldn't update the value stored in the context, would it? It would only update the let client variable.

Where does this let client actually get set to the client from async function preload? I guess I need to understand Sapper more to know how this works, but it doesn't seem like it could.

Update: I think I found the answer (it runs before):

https://hyp.is/3aHeJgNFEeunkCsh8FVbDQ/sapper.svelte.dev/docs/

It lives in a context="module" script — see the tutorial — because it's not part of the component instance itself; instead, it runs before the component is created, allowing you to avoid flashes while data is fetched.

Cellini, N., Di Giorgio, E., Mioni, G., & Di Riso, D. (2020). Sleep quality, timing, and psychological difficulties in Italian school-age children and their mothers during COVID-19 lockdown [Preprint]. PsyArXiv. https://doi.org/10.31234/osf.io/95ujm

Boseley, S. (2020, May 12). Millions with health conditions at risk from Covid-19 “if forced back to work.” The Guardian. https://www.theguardian.com/world/2020/may/12/millions-with-health-conditions-at-risk-from-covid-19-if-forced-back-to-work

Di Giorgio, E., Di Riso, D., Mioni, G., & Cellini, N. (2020, April 30). The interplay between mothers’ and children behavioral and psychological factors during COVID-19: An Italian study. Retrieved from psyarxiv.com/dqk7h