Missing types in @sveltejs/kit

[iva2k]

Describe the bug

Setup

npm init svelte my-app
# choose:
# demo app
# TypeScript
# ESLint
# Prettier
# Playwright

cd my-app
pnpm install

Run check

pnpm run check
# no errors

Modify tsconfig.json:

{
    "extends": "./.svelte-kit/tsconfig.json",
    "compilerOptions": {
        "allowJs": true,
        "checkJs": true,
        "esModuleInterop": true,
        "forceConsistentCasingInFileNames": true,
        "resolveJsonModule": true,
        "skipLibCheck": true,
        "sourceMap": true,
        "strict": true,
+        "outDir": ".types",
+        "paths": {
+            "$app/*": [".svelte-kit/runtime/app/*"],
+            "$lib": ["src/lib"],
+            "$lib/*": ["src/lib/*"]
+        }
    }
}

Run check with modified tsconfig.json

pnpm run check

Expected: no errors

Actual: 2 errors

The same 2 errors are thrown when just running tsc.

Reproduction

https://github.com/iva2k/sveltejs-kit-issue-types-20220529

Logs

C:\dev\svelte\my-app>pnpm run check
> my-app@0.0.1 check C:\dev\svelte\my-app
> svelte-check --tsconfig ./tsconfig.json

====================================
Loading svelte-check in workspace: c:\dev\svelte\my-app
Getting Svelte diagnostics...

c:\dev\svelte\my-app\.svelte-kit\runtime\client\singletons.js:1:19
Error: Cannot find module './types' or its corresponding type declarations.
/** @type {import('./types').Client} */
let client;

c:\dev\svelte\my-app\.svelte-kit\runtime\client\singletons.js:6:21
Error: Cannot find module './types' or its corresponding type declarations.
 * @param {{
 *   client: import('./types').Client;
 * }} opts

====================================
svelte-check found 2 errors, 0 warnings, and 0 hints
ELIFECYCLE  Command failed with exit code

System Info

System:
    OS: Windows 10 10.0.19044
    CPU: (8) x64 Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz
    Memory: 4.17 GB / 15.74 GB
  Binaries:
    Node: 18.1.0 - C:\nodejs\node.EXE
    Yarn: 1.22.15 - C:\nodejs\yarn.CMD
    npm: 8.10.0 - C:\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1266.0), Chromium (101.0.1210.53)
    Internet Explorer: 11.0.19041.1566
  npmPackages:
    @sveltejs/adapter-auto: next => 1.0.0-next.48
    @sveltejs/kit: next => 1.0.0-next.345
    svelte: ^3.46.0 => 3.48.0

Severity

serious, but I can work around it

Additional Information

Apparently, defining $app alias in tsconfig.json enables Typescript to analyze import('$app/navigation') in forms.ts, which pulls in files that lack Typescript types. Removing $app from tsconfig.json.compilerOptions.paths hides the problem,

I checked @sveltejs/kit repo, and found some *.d.ts files that are not bundled into the distributed package, and one of them (@sveltejs/kit/packages/kit/src/runtime/client/types.d.ts) contains interface Client, which is missing in the bundle.

This issue manifested itself when making a fix for #1560, and remains hidden until $app alias is defined.

[iva2k]

Possibly related to work in #2514

[dummdidumm]

This works as expected. $app/* imports are supposed to be typed through this ambient file which is picked up through the /// reference at the top of app.d.ts. $app/* types are not meant to be resolved through the generated code. Just remove the $app/* reference from your paths definition.

[iva2k]

Thanks for quick response @dummdidumm. However...

Removing $app from paths breaks bunch of import lint checks in #1560. Which is not good to have unchecked and therefore possibly broken imports. Adding $app fixed all of these lint errors. Is there other way to have all imports linted in my proposed fix in #1560? ESLint does not seem to be picking up the /// reference.

But my point here is different - it is that typedef interface Client is not to be found in any .d.ts files in the packaged @sveltejs/kit, but it is used by the demo app. I inspected the code, found the typedef, and see that the typedef is not picked up by rollup config.

My ask here is to add typedef interface Client to the @sveltejs/kit package types.

[iva2k]

Bump!
Please consider reopening.

ask here is to add typedef interface Client to the @sveltejs/kit package types, since it is exposed in the API, but not present in types. For one, ESLint is not finding the types based on /// reference.

[dummdidumm]

Where is Client exposed in the API exactly? Not sure I follow.

[iva2k]

@dummdidumm

Where is Client exposed in the API exactly? Not sure I follow.

The Client type is pulled from file ".svelte-kit/runtime/client/singletons.js"

which has this line at the top: /** @type {import('./types').Client} */

The file is created by Svelte-kit.

The steps to get the error are trivial and listed in the issue, I also posted a repro repo:
https://github.com/iva2k/sveltejs-kit-issue-types-20220529

Have you looked at it?