svelte-package removes type="application/ld+json" from script tags

[TeemuKoivisto]

Describe the bug

Running svelte-package removes type="application/ld+json" from script tags even with preserve: ['ld+json'] using:

<svelte:head>
  {@html `<script type="application/ld+json" >${JSON.stringify(jsonLd)}</script>`}
</svelte:head>

is compiled to:

<svelte:head>
  {@html `<script >${JSON.stringify(jsonLd)}</script>`}
</svelte:head>

Reproduction

https://github.com/TeemuKoivisto/svelte-package-removes-jsonld-type

Logs

No response

System Info

System:
    OS: macOS 12.5.1
    CPU: (10) arm64 Apple M1 Pro
    Memory: 75.28 MB / 32.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 16.17.0 - ~/.nvm/versions/node/v16.17.0/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v16.17.0/bin/yarn
    npm: 8.15.0 - ~/.nvm/versions/node/v16.17.0/bin/npm
  Browsers:
    Chrome: 105.0.5195.125
    Firefox: 104.0.1
    Safari: 15.6.1
  npmPackages:
    @sveltejs/kit: ^1.0.0-next.484 => 1.0.0-next.484 
    @sveltejs/package: ^1.0.0-next.3 => 1.0.0-next.3 
    svelte: ^3.50.1 => 3.50.1 
    vite: ^3.1.1 => 3.1.1

Severity

serious, but I can work around it

Additional Information

No response

[dominikg]

The cause of this is that parsing script blocks to pass to preprocessors is done in a very fast and simplistic way. It also finds script tags nested in strings.

The workaround you linked to breaks apart the script tags in the sourcecode, so that they are not found by the parser, not passed through svelte-preprocess - which ultimately strips the type.

You already found the preserve option, but i think it would have to be preserve: 'application/ld+json' unfortunately it looks like that produces a different error

> Cannot find module './transformers/ld+json'
Require stack:
- /home/dominikg/develop/reproductions/svelte-package-removes-jsonld-type/node_modules/.pnpm/[email protected]_52dhhvjbzvlifk77xwmrmntvea/node_modules/svelte-preprocess/dist/autoProcess.js
- /home/dominikg/develop/reproductions/svelte-package-removes-jsonld-type/node_modules/.pnpm/[email protected]_52dhhvjbzvlifk77xwmrmntvea/node_modules/svelte-preprocess/dist/index.js
Require stack:
- /home/dominikg/develop/reproductions/svelte-package-removes-jsonld-type/node_modules/.pnpm/[email protected]_52dhhvjbzvlifk77xwmrmntvea/node_modules/svelte-preprocess/dist/autoProcess.js
- /home/dominikg/develop/reproductions/svelte-package-removes-jsonld-type/node_modules/.pnpm/[email protected]_52dhhvjbzvlifk77xwmrmntvea/node_modules/svelte-preprocess/dist/index.js
    at Module._resolveFilename (node:internal/modules/cjs/loader:956:15)

so for now if you have to inject script tags via svelte:head + @html - which i am not too fond of in general. The workaround with splitting the script tag is what makes it work.

In a future version of svelte and/or svelte-preprocess, the way script tags are processed might change to avoid this.

There isn't much sveltekit or svelte-package could do about this, the issue should be transferred to either svelte or svelte-preprocess repo, or maybe closed with a ref to an existing issue related to this
eg sveltejs/svelte-preprocess#305 or sveltejs/svelte#5292

[TeemuKoivisto]

@dominikg okay, yeah I think passing preserve should preserve the attributes as well so svelte-preprocess might be the right place. Agree about injecting script tags not being ideal yet that's how they decided to distribute the graph data.

[dummdidumm]

This is a bug in svelte-package, adding preserve: ['ld+json'] should work.

[TeemuKoivisto]

Yup, fixed with the latest package, amazing - thanks!