build(deps): update dependency typescript to v5

[marcalexiei]

Summary

Support typescript@5

• Update typescript version in

  • devDependencies
  • peerDependencies and ExpectedVersions enum
  • website folder package.json

• added a casting on transformer function inside src/transformers/hoist-jest.ts. Error might being caused by TS internal API changes

  The VisitResult type is no longer undefined by default; if you have written VisitResult, you may need to rewrite it as VisitResult<Node | undefined> to reflect that your visitor may return undefined.

  Visitor-using APIs now correctly reflect the type of the output, including whether it passed a given type guard test, and whether or not it may be undefined. In order to get the type you expect, you may need to pass a test parameter to verify your expectations and then check the result for undefined (or, modify your visitor to return a more specific type).

• spyOn on ts methods is not working anymore so I added a jest.mock('typescript') and changed ts import to import * as ts from 'typescript'in all spec files requiring typescript module.

• I removed @types/node-fetch package since it is a stub.

Test plan

With node@16.19.1
npx tsc -version && npm run test

Does this PR introduce a breaking change?

• Yes
• No

I tried running above command with ts 4.9.3 and all tests have passed.

Other information

Related PR / issues

• [Feature]: Typescript 5 support #4048
• build(deps): Update dependency typescript to v5 - abandoned #4052

[marcalexiei]

It looks like custom-compiler.test fails with the error (I print out the json returned from runWithJson function):
Loading module ttypescript failed with error: Cannot find module 'ttypescript'

The error seems generated by Importer#tryThese function.

The strange thing is that the issue isn't occurring in node 16 / 18.

@ahnpnl do you have any idea about why this is happening?

[marcalexiei]

Update:
Looks like the require of 'ttypescript' returns a type error but only on node 14:
TypeError: Cannot set property createProgram of #<Object> which has only a getter

It seems an issue on ttypescript itself: cevek/ttypescript#140.
This behaviour is caused by the typescript library target change from es5 to es2018 (now typescript exports modules rather than namespace objects that can be easily changed).
More info can be found here: microsoft/TypeScript#52826.

Maybe you can consider to disable those tests and re-enable them in a later date when the library has fully supported typescript@5?

Still... I can't understand why this is working on node16 and 18 😅

[ahnpnl]

I think we can disable that test since we know the upstream issue.

[marcalexiei]

I added a separate commit to skip the test.
I also referenced this PR and related ttypescript and typescript issues in a comment to easily track the reason of the skipping and remove it in the future.

[coveralls]

Pull Request Test Coverage Report for Build 4526037649

• 5 of 5 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 95.833%

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Totals
Change from base Build 4520861791:	0.0%
Covered Lines:	4055
Relevant Lines:	4154

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💛 - Coveralls

[ahnpnl]

thanks!