[BUG] JSON imports fail at runtime with bundler

[cloudhead]

Bug Report Quick Checklist

• I am on the latest version of Snowpack & all plugins.
• I use package manager npm (Fill in: npm, yarn, pnpm, etc).
• I run Snowpack on OS Linux (Fill in: Windows, Mac, Linux, etc).
• I run Snowpack on Node.js v12+

Describe the bug

• I have an import config from "./config.json" in one of my typescript files.
• This builds fine, with no errors, however when the app is opened in the browser, I get an error in the console: Failed to load module script: The server responded with a non-JavaScript MIME type of "application/json". Strict MIME type checking is enforced for module scripts per HTML spec.

To Reproduce

1. npx create-snowpack-app dir --template @snowpack/app-template-svelte-typescript
2. Create a .json file in src/ and import it from index.ts.
3. Set bundle: true in snowpack's optimize config
4. npm run build
5. Go in the build/ folder and start a webserver
6. Open the app in your browser
7. See error in the console!

Expected behavior

There should be no error. The .json file should import without problem, just like with bundle: false.

Anything else?

Looks like the issue is caused by bundle: true.

[awu43]

Looks like the same as #3109, try the workaround here.

[amatiash]

I have the same issue. Fails to load logo.svg. When bundle: true