app-template-svelte-typescript fails to compile App.svelte if unrelated test import is removed

[lpil]

Hello! I've come across a problem where the application code no longer compiles when a test library import is removed from a seemingly unrelated file.

Steps to reproduce

# Create project with the template
npx create-snowpack-app theapp --template @snowpack/app-template-svelte-typescript

# Enter the project
cd theapp

# Verify that the project works
npm start # This succeeds

# Remove the test file
rm src/App.test.ts

# Now the project fails to build citing an unrelated file not being found
npm start

In this example I've removed the entire file, but it is enough to remove or comment out just this line:
https://github.com/snowpackjs/snowpack/blob/0f9d34b8cf747e33524b31920d5610f6403c5480/create-snowpack-app/app-template-svelte/src/App.test.js#L1

The error

snowpack

  http://localhost:8080 • http://172.17.16.208:8080
  Server started in 19ms.

▼ @snowpack/plugin-typescript

  7:47:50 PM - Starting compilation in watch mode...

  src/index.ts(1,17): error TS2307: Cannot find module './App.svelte' or its corresponding type declarations.

  7:47:52 PM - Found 1 error. Watching for file changes.

How might I remove this test file while without breaking compilation of the app?

Versions

Ubuntu 20.04
Node v14.15.1
npm 6.14.8
@snowpack/app-template-svelte-typescript 2.0.5

[melissamcewen]

Hi @lpil thanks for reporting. Going to pass this one on to the other maintainers to take a look at since I don't specialize in TS.

[lpil]

Thank you Melissa!

[thisislawatts]

👋 heya @lpil,

Not sure if you ever got to the bottom of this but I managed to get this working following the advice in this SO thread:
https://stackoverflow.com/questions/64194571/cannot-find-module-app-svelte-or-its-corresponding-type-declarations

[lpil]

That did the trick! Thank you @thisislawatts

@melissamcewen it looks like we may need to add the npm i --save-dev @tsconfig/svelte dep and add "extends": "@tsconfig/svelte/tsconfig.json", to .tsconfig.json for that template.

[frederikhors]

After adding @tsconfig/svelte now I have another error in my index.ts file:

Property 'hot' does not exist on type 'ImportMeta'.ts(2339).

😭

[frederikhors]

I can fix it by using #1433 (comment)

[frederikhors]

I opened #2863.

[stautonico]

For anyone else having this issue, I solved this issue by adding "svelte" to your "types" in your "tsconfig.json". Example:
"types": ["node", "svelte"],

[K-Sato1995]

You sir just saved my day!

[egeergul]

Sir thank you!!!!