Svelte 5: getContext is undefined.

[HighFunctioningSociopathSH]

Describe the bug

Since the last update (svelte@5.0.0-next.206), svelte throws an error saying getContext is undefined if getContext was called in a svelte.ts file. works fine in next.205

Reproduction

test.svelte.ts

import { getContext } from "svelte";

export function fetchContext() {
  const test = getContext("something");

  return test;
}

Child.svelte

<script lang="ts">
  import { fetchContext } from "./test.svelte";

  const result = fetchContext();
</script>

Logs

client.js?v=731e5348:299 Uncaught (in promise) 
ReferenceError: getContext is not defined
    at fetchContext (test.svelte.ts:4:16)
    at Child (Child.svelte:4:18)
    at chunk-KRQXFADS.js?v=731e5348:209:58
    at update_reaction (chunk-IUDHG5ZN.js?v=731e5348:1093:23)
    at update_effect (chunk-IUDHG5ZN.js?v=731e5348:1213:21)
    at create_effect (chunk-IUDHG5ZN.js?v=731e5348:274:7)
    at branch (chunk-IUDHG5ZN.js?v=731e5348:398:10)
    at chunk-KRQXFADS.js?v=731e5348:202:17
    at update_reaction (chunk-IUDHG5ZN.js?v=731e5348:1093:23)
    at :5174/update_effect …text is not defined
    at fetchContext (test.svelte.ts:4:16)
    at Child (Child.svelte:4:18)
    at chunk-KRQXFADS.js?v=731e5348:209:58
    at update_reaction (chunk-IUDHG5ZN.js?v=731e5348:1093:23)
    at update_effect (chunk-IUDHG5ZN.js?v=731e5348:1213:21)
    at create_effect (chunk-IUDHG5ZN.js?v=731e5348:274:7)
    at branch (chunk-IUDHG5ZN.js?v=731e5348:398:10)
    at chunk-KRQXFADS.js?v=731e5348:202:17
    at update_reaction (chunk-IUDHG5ZN.js?v=731e5348:1093:23)
    at update_effect (chunk-IUDHG5ZN.js?v=731e5348:1213:21)

System Info

System:
    OS: Windows 11 10.0.22631
    CPU: (16) x64 12th Gen Intel(R) Core(TM) i7-12650H
    Memory: 4.54 GB / 15.63 GB
  Binaries:
    Node: 20.12.2 - C:\Program Files\nodejs\node.EXE
    npm: 10.8.2 - C:\Program Files\nodejs\npm.CMD
    bun: 1.1.3 - ~\.bun\bin\bun.EXE
  Browsers:
    Edge: Chromium (126.0.2592.102)
    Internet Explorer: 11.0.22621.3527

Severity

blocking an upgrade

[brunnerh]

Looks like a duplicate of:

• Svelte@5-next.206 breaks browser from $app/environment #12703
• Unable to import other *.ts files from a *.svelte.ts file #12706