chore(deps): bump TypeScript to v4.9.5

[mrazauskas]

Summary

Upgrading to TypeScript v5 is currently blocked by @microsoft/api-extractor, because it throws if the ignoreDeprecations compiler option is around. This makes it impossible to use the option with TypeScript 4.9.5 too.

ignoreDeprecations will also be a problem when testing types on older versions of TypeScript. This PR is changing tsconfig.json used for type testing. I think it makes sense to extend from node14 base instead on tsconfig.json which is used for build.

The compiler config for type testing was mostly unsetting some build options like composite. That was nice shortcut, but I think type testing shouldn’t be somehow too much related with build config. It has to work with older versions, so I am trying to reshape it here.

Test plan

Green CI

[mrazauskas]

Hm.. Can’t understand why TS v5.0.2 is used for typechecks:

api-extractor sees TS v4.9.4 during build:

Actually tsc should complain about the importsNotUsedAsValues option as well if repo would be build using TS v5.0.2, but it does not.

[mrazauskas]

Seems like I got through that glitch by moving typechecks to separate job. I was thinking to suggest this at some point, simply to make the TypeScript Compatibility job lighter. The build:ts step is needed, but perhaps that’s fine?

Note that in the new job I skipped ts:bundle, because it removes tsconfig.tsbuildinfo files. The typechecks run through tsc --build, which would rebuild packages if tsconfig.tsbuildinfo files are not found. Another approach could be to make the bundle step take some flag, e.g. ts:bundle --skip-cleanup.

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I was playing locally a bit. tsconfig.json for tests has "skipLibCheck": true compiler option. If tsconfig.tsbuildinfo files are left in place, tsc assumes that production code is up to date. This means that tsc does not deep check production types even though production tsconfig.json has "skipLibCheck": false option.

This is one of the reasons why I think it is good idea to keep typechecks in a separate job. Here it would be just fine to leave the outdated tsconfig.tsbuildinfo files after bundling.

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Hard to say where was TypeScript v5 coming from. Was it because of removed tsconfig.tsbuildinfo files? Or is something wrong with the verify-old-ts script? I have one idea how to rework testing on older version of TS, so leaving it for now.

[SimenB]

Thanks! Very odd CI started failing, but I can't be bothered to dif into it 😅

[eps1lon]

#14055 fixes this without having to split jobs and should be landed regardless since it'll fix bugs when you run old compat tests locally.

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