Error(sveltekit): Package subpath './vite' is not defined by "exports"

[thenbe]

Knip errors on fresh sveltekit project.

npm create svelte@latest knip-demo
# choice 1: SvelteKit demo app
# choice 2: Yes, using typescript syntax.
cd knip-demo
npm i
npx knip

$ npx knip
Analyzing workspace ....
Error loading /home/nbe/projects/playground/knip-demo/vite.config.ts
Reason: Package subpath './vite' is not defined by "exports" in /home/nbe/projects/playground/knip-demo/node_modules/@sveltejs/kit/package.json

Relevant #99

[webpro]

Thanks for the report. The only solution I can offer at this point is to update Knip to v2.41.1 and rename vite.config.ts → vite.config.js (or vite.config.mjs without updating).

The issue you link to is indeed relevant, but in the Vite plugin is now loading the Vite config file, since it might contain Vitest configuration that should be parsed for dependencies.

Not sure yet how to deal with the Jiti issue, though.

[webpro]

The situation has further improved in v2.41.2, but it's not fixed yet.

The ESM issue and loading TS in general works fine, but calling sveltekit() results in:

[ '[...]/vite.config.ts' ]
[...]/knip/dist/util/loader.js:37
        throw new LoaderError(`Error loading ${filePath}`, { cause: error });
              ^

LoaderError: Error loading [...]/vite.config.ts
    at load ([...]/knip/dist/util/loader.js:37:15)
    at Module.findViteDependencies ([...]/knip/dist/plugins/vite/index.js:9:31)
    ... 5 lines matching cause stack trace ...
    at async [...]/knip/dist/cli.js:74:1 {
  [cause]: [...]/node_modules/@sveltejs/kit/src/core/sync/ts.js:5
    exports.ts = ts = (await Promise.resolve().then(() => require('typescript'))).default;
                             ^^^^^^^
  
  SyntaxError: Unexpected identifier 'Promise'
      at new Script (node:vm:93:7)
      at createScript (node:vm:248:10)
      at Object.runInThisContext (node:vm:296:10)
      at evalModule ([...]/knip/node_modules/jiti/dist/jiti.js:1:256254)
      at jiti ([...]/knip/node_modules/jiti/dist/jiti.js:1:254371)

[thenbe]

jiti seems to choke when it hits this file in the vite sveltekit plugin:

/** @type {import('typescript')} */
// @ts-ignore
export let ts = undefined;
try {
	ts = (await import('typescript')).default;
} catch {}

It prints this error:

> exper-jiti-vite@1.0.0 start /home/nbe/projects/playground/exper-jiti-vite
> jiti src/jiti.ts

[jiti] [transpile] [esm] /home/nbe/projects/playground/exper-jiti-vite/ts.js (4.047ms)
/home/nbe/projects/playground/exper-jiti-vite/ts.js:5
  exports.ts = ts = (await Promise.resolve().then(() => require('typescript'))).default;
                           ^^^^^^^

SyntaxError: Unexpected identifier 'Promise'
    at new Script (node:vm:99:7)
    at createScript (node:vm:247:10)
    at Object.runInThisContext (node:vm:295:10)
    at evalModule (/home/nbe/projects/playground/exper-jiti-vite/node_modules/.pnpm/jiti@1.21.0/node_modules/jiti/dist/jiti.js:1:256254)
    at jiti (/home/nbe/projects/playground/exper-jiti-vite/node_modules/.pnpm/jiti@1.21.0/node_modules/jiti/dist/jiti.js:1:254371)
    at /home/nbe/projects/playground/exper-jiti-vite/src/jiti.ts:25:13
    at evalModule (/home/nbe/projects/playground/exper-jiti-vite/node_modules/.pnpm/jiti@1.21.0/node_modules/jiti/dist/jiti.js:1:256443)
    at jiti (/home/nbe/projects/playground/exper-jiti-vite/node_modules/.pnpm/jiti@1.21.0/node_modules/jiti/dist/jiti.js:1:254371)
    at Object.<anonymous> (/home/nbe/projects/playground/exper-jiti-vite/node_modules/.pnpm/jiti@1.21.0/node_modules/jiti/bin/jiti.js:16:1)
    at Module._compile (node:internal/modules/cjs/loader:1376:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1435:10)
    at Module.load (node:internal/modules/cjs/loader:1207:32)
    at Module._load (node:internal/modules/cjs/loader:1023:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:135:12)
    at node:internal/main/run_main_module:28:49

Node.js v20.10.0
 ELIFECYCLE  Command failed with exit code 1.

---

I'm not very confident I understand what's happening, but it looks like we want to instruct jiti to avoid transforming this file, as it is "already ESM"? I found this jiti thread as well where sveltekit is mentioned.

[webpro]

Knip v5.1 introduce a new workaround: bunx --bun knip

[webpro]

See #565