lib: check SharedArrayBuffer existence in fast-utf8-stream

[codebytere]

Refs #58897

Fixes the following error:

"Uncaught ReferenceError: SharedArrayBuffer is not defined"

caused by changes in the above PR that declare const kNil = new Int32Array(new SharedArrayBuffer(4)); when lib/internal/streams/fast-utf8-stream.js is imported and Utf8Stream() is used. This causes an error in any environment missing a SharedArrayBuffer.

I used an alternative sleep implementation in the missing case, but am happy to rework this however is preferred.

[nodejs-github-bot]

Review requested:

• @nodejs/streams

[aduh95]

Is the haveSAB variable useful?

Suggested change

	const haveSAB = typeof SharedArrayBuffer !== 'undefined';
	const kNil = haveSAB ? new Int32Array(new SharedArrayBuffer(4)) : null;
	const kNil = SharedArrayBuffer && new Int32Array(new SharedArrayBuffer(4));

[codebytere]

@aduh95 we need it below to choose sleep implementation, no?

[aduh95]

We could use kNil for that

[targos]

The suggested code would throw an error if SharedArrayBuffer is not defined.

[aduh95]

It is declared above, it wouldn't throw even if undefined:

node/lib/internal/streams/fast-utf8-stream.js

Line 15 in 6547f21

SharedArrayBuffer,

[mcollina]

lgtm

[codecov]

Codecov Report

❌ Patch coverage is 37.50000% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.54%. Comparing base (ddbe136) to head (38de540).
⚠️ Report is 75 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/streams/fast-utf8-stream.js	37.50%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #60453      +/-   ##
==========================================
- Coverage   88.59%   88.54%   -0.05%     
==========================================
  Files         704      704              
  Lines      207774   207848      +74     
  Branches    40035    40045      +10     
==========================================
- Hits       184068   184036      -32     
- Misses      15748    15850     +102     
- Partials     7958     7962       +4     

Files with missing lines	Coverage Δ
lib/internal/streams/fast-utf8-stream.js	73.80% <37.50%> (-0.41%)	⬇️

... and 66 files with indirect coverage changes

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[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/70022/