ci: transcribe esm tests to TypeScript

[wellwelwel]

The intention is, once 100% of the tests are transcribed to TypeScript in the future, to completely remove the ./test/tsc-build directory.

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Advantages

• Easier to identify inconsistencies between JavaScript code and separately created types (d.ts) naturally while tests are being created.
• More than 20 typing inconsistencies were found just in ./test/esm that went unnoticed by ./test/tsc-build 🔥
• Makes it easier to review contributions such as fix: promise connection typescript mismatched to underlying code #3321 and fix: types for query values #3985.
• Looking ahead, it avoids test redundancy/mirroring due to types (one directory to test types without execution, another to test JavaScript).

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Important

No files inside the core (lib, index.js, etc.) were modified and remain totally untouched 🙋🏻‍♂️

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Note

Since for Poku there is no difference between running CJS, ESM, or TypeScript files in the same test suite (regardless of the runtime or coverage), there is no need to make any adaptations to the source code (lib), while we can take the first step towards #2803.

The legacy version of Deno that used a polyfill has been removed from the workflow since it is incompatible with require + dynamic typings.

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Related

• Improve contributors and users experience #3695

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.95%. Comparing base (a06c241) to head (6d98cb8).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4086   +/-   ##
=======================================
  Coverage   89.95%   89.95%           
=======================================
  Files          86       86           
  Lines       13663    13663           
  Branches     1637     1637           
=======================================
  Hits        12291    12291           
  Misses       1372     1372           

Flag	Coverage Δ
compression-0	89.07% <ø> (ø)
compression-1	89.93% <ø> (ø)
static-parser-0	87.54% <ø> (ø)
static-parser-1	88.30% <ø> (ø)
tls-0	89.36% <ø> (ø)
tls-1	89.73% <ø> (ø)

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[wellwelwel]

All type inconsistencies are marked with: // @ts-expect-error: TODO: implement typings. Some of them have already been reported, but without reproduction until now. For example:

• Some types are incorrect on mysql2 (callback based) but not mysql2/promise #3964
• Incorrect typings lead to pool.destroy is not a function #2667

From here on, types are no longer a compilation test and become an integral part of the tests that are actually executed ✨