Upgrade from 4.8.0 - 4.9.0: unterminated string literal error during svelte-check, build fails

[mlandisbqs]

Describe the bug
Isolated to 4.9.0 code changes (4.8.0 compiles the same code without the bug):
https://github.com/sveltejs/svelte-preprocess/compare/v4.8.0...v4.9.0?short_path=61c21cb#diff-96443e2ca98f566a13837889beb8b5a9da9d97c396ad64bc3a28dbf0e3557f37

After the upgrade -- the generated code contains unterminated string literal which typescript then fails to compile.
This happens right here in the code (line 140, src/transformers/typescript.ts):

^-- the codestores array includes an entry like this ["'"]

Logs

rc/components/script-response/input-type/single-input-type.svelte.injected.ts:74:224 - error TS1002: Unterminated string literal.

74 const $$vars$$ = [sessionStore,sessionStore,',promptResponse,prompt,$sessionStore,sessionStore,prompt,promptResponse,BqpTextField,label,type,error,optional,unit,textarea,inputAttrs,prompt,value,persistChange,persistChange];
                                                                                                                                                                                                                                  

src/components/script-response/input-type/range-input-type.svelte.injected.ts:89:209 - error TS1002: Unterminated string literal.

89 const $$vars$$ = [',promptResponses,BqpGroup,highlight,$sessionStore,sessionStore,prompt,BqpTextField,type,unit,fromValue,persistChange,BqpTextField,type,unit,fromValue,toValue,isValid,toValue,persistChange];
                                                                                                                                                                                                                   

Expected behavior
codestores should be captured without a single quote value in the array.

Information about your project:

• Your browser and the version: (e.x. Chrome 52.1, Firefox 48.0, IE 10)

• Your operating system: (e.x. OS X 10, Ubuntu Linux 19.10, Windows XP, etc)
  MacOs 10.15.4

• svelte-preprocess version (Please check you can reproduce the issue with the latest release!)
  4.9.0 (same problem on latest release)

• Whether your project uses Webpack or Rollup
  rollup

[mlandisbqs]

This looks like it could be related to #401

[kaisermann]

Hey, @mlandisbqs 👋 Thanks for the report! Can you share your file content or at least all identifiers beginning with $?

[mlandisbqs]

ok - I actually think I see the issue... both of the files that have problems have a string literal with a dollar sign...

...I haven't tested removing it yet, but that must be the issue. I'm not sure that I can share the whole component file.

[kaisermann]

That's more than enough and is probably the culprit. This helps a lot, thanks!

[seanlail]

@kaisermann I'm sure you have enough info, but just in case:

I just ran into the same thing with this code:

<script lang="ts">
  export let code = "gbp";

  const symbols: Record<string, string> = { eur: "€", gbp: "£", usd: "$" };

  $: symbol =
    !!code && symbols[code.toLowerCase()] ? symbols[code.toLowerCase()] : "";
</script>

{symbol}

src/components/CurrencySymbol.svelte.injected.ts:11:29 - error TS1002: Unterminated string literal.
11 const $$vars$$ = [",symbol];

and can confirm that removing usd: "$" works

[seanlail]

This breaks in 4.8.0 for me. Only 4.7.4 and older worked.

[dummdidumm]

Found the culprit, will prepare a PR shortly

[kaisermann]

Fix released in v4.9.4 🎉 . Thanks @dummdidumm!