JS: Various TypeScript extraction fixes.

[erik-krogh]

And add a new SEMMLE_TYPESCRIPT_SKIP_EXTRACTING_TYPES environment variable to skip extraction of all types.
This is a workaround for an internal report about long extraction times.

I'm not sure why those fixes weren't needed previously, and I couldn't replicate them when running tests.
They're clearly basic TypeScript errors, so I'm not sure what's going on.
I think it's something for @asgerf to look at when he's back?

I tried the new flag locally on microsoft/vscode.
The extraction got faster, and we only lost a single alert on that project.
And extraction is way faster with the flag on a minimal example from the internal report.

Evaluation were very uneventful (nightly-old.yml, typescript-full.yml)

[aibaars]

Looks good to me. Shall we change the name of the environment variable to match the ones for extractor options?

[erik-krogh]

Looks good to me. Shall we change the name of the environment variable to match the ones for extractor options?

That sounds like a good idea.
I haven't looked into those. Have you? What would the name be?

[aibaars]

I haven't looked into those. Have you? What would the name be?

The prefix is CODEQL_EXTRACTOR_JAVASCRIPT_OPTION_ . If you want to document the flag as a proper extractor option you can add something like this https://github.com/github/codeql/blob/main/csharp/codeql-extractor.yml#L19-L50 to the codeql-extractor.yml file.

[erik-krogh]

Thanks for the pointer.
The codeql-extractor.yml file for the JS extractor is in our internal repository, so I'll look into updating that file in a followup PR.