Reactivity breaks due to an assignment in `$effect.pre`

[x0k]

Describe the bug

I'm not sure why this happens, but changing $effect.pre to $effect makes everything work

Reproduction

REPL
Expected: after clicking on switch, oneOf = oneOf should be displayed.

Logs

System Info

System:
    OS: Linux 6.6 cpe:/o:nixos:nixos:24.11 24.11 (Vicuna)
    CPU: (12) x64 Intel(R) Core(TM) i5-10400F CPU @ 2.90GHz
    Memory: 7.33 GB / 15.56 GB
    Container: Yes
    Shell: 5.2.37 - /run/current-system/sw/bin/bash
  Binaries:
    Node: 23.11.0 - /nix/store/qsbvdw53nbhnzad466fvgczrw9kxc1vh-nodejs-23.11.0/bin/node
    npm: 10.9.2 - /nix/store/qsbvdw53nbhnzad466fvgczrw9kxc1vh-nodejs-23.11.0/bin/npm
    pnpm: 10.10.0 - /nix/store/jrbb8492jbrnzwby1a9ilvv66pyyjy29-pnpm-10.10.0/bin/pnpm
  Browsers:
    Brave Browser: 136.1.78.102
  npmPackages:
    svelte: catalog: => 5.33.14

Severity

annoyance