since htmlparser2@8 type declaration requires ts >= 4.5

[olivier-martin-sf]

It looks like since #1165 landed in the repo, the bundled type declarations use mixed exports (exporting both type and values) which was introduced in TS 4.5 AFAIK.

I am wondering if there's an assumption that the consumer of the package runs a specific version of TS since the [email protected] release line. I tried to use that library in a project that runs under TS 4.2 and the type checker errors out as it doesn't understand the mixed exports syntax. That's the kind of error that are being thrown:

node_modules/htmlparser2/lib/index.d.ts:2:23 - error TS1005: ',' expected.

2 export { Parser, type ParserOptions };
                        ~~~~~~~~~~~~~

Maybe we could add a note about the minimum TS requirement or provide backward compatible type declarations (relying on typesVersion and using a tool such as downlevel-dts).

Thank you so much for your work on this awesome lib and hopefully this is useful feedback

[lehui521]

I encountered the same problem

[fb55]

I have added a note to the 8.0.0 release notes: https://github.com/fb55/htmlparser2/releases/tag/v8.0.0

The 7.x releases are still safe to use for users on older TypeScript versions, and I don't see a strong reason to maintain backwards compatibility for old TypeScript releases. Hope that makes sense!

[a-liubchenka]

@fb55 Hi
I spent lots of time today, just due to this problem.
Could you please add perDependencies object in package.json with typescript requirement?
After that I will be notified, that there is a conflict between typescript version requirements. Currently just some magic(

[fb55]

It is possible to use this module without TypeScript. If I added TypeScript as a peer dependency, users that don't use TypeScript would get errors. Unfortunately there is no way to specify optional peer dependencies.