lib: unify ICU and no-ICU TextDecoder

[ChALkeR]

Better reviewed with whitespace ignored

1. Fix TextDecoder defaults to stream: true instead of false with null options #61411
2. Add support for fatal UTF-8 decoder in no-ICU version unless streaming is used
3. add utf-8 fast path to no-ICU version
4. reduce duplication of TextDecoder source
5. normalize how this[kHandle] was not set in no-ICU version
6. The refactor changes the encoding reported in the no-ICU version when encoding is recognized but unsupported: now the actual resolved encoding name is reported as unsupported when previously the original input string was reported.
   I don't think this is major, and reporting the actual encoding name is better in that case.

This will allow further fixes and common fast path for UTF-16 / fixed impl for UTF-16 as string_decoder doesn't implement UTF-16 per spec.

UTF-16 is still broken in no-ICU version here, this PR does not address that.
Tracking: #61041

[nodejs-github-bot]

Review requested:

• @nodejs/startup

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.78%. Comparing base (77e8d44) to head (54e7ba2).
⚠️ Report is 38 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #61409      +/-   ##
==========================================
- Coverage   89.87%   89.78%   -0.09%     
==========================================
  Files         671      672       +1     
  Lines      203178   203876     +698     
  Branches    39062    39186     +124     
==========================================
+ Hits       182599   183051     +452     
- Misses      12926    13142     +216     
- Partials     7653     7683      +30     

Files with missing lines	Coverage Δ
lib/internal/encoding.js	100.00% <100.00%> (ø)

... and 70 files with indirect coverage changes

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[avivkeller]

There's a lazy utility in the internal utils.

[ChALkeR]

@avivkeller this is not new code, it's just moved to an outer scope
Ideally all that should go away with follow-up fixes, string_decoder path is invalid anyway
I don't think it's worth refactoring it further

[anonrig]

I still think we should use the new lazy module. Regardless of this being new code or not, git sees it as a new code.

[ChALkeR]

@anonrig Next two prs will remove this anyway. This is going in iterative steps, the intention of this PR is to make rewrite easier, not to be that rewrite. I don't think it should be blocked on rewriting a code block that wasn't introduced here and is gonna be removed.

[ChALkeR]

Rebased, no actual changes

[gurgunday]

lgtm

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71011/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71031/

[richardlau]

The withoutintl test failure looks related.
https://ci.nodejs.org/job/node-test-commit-linux-containered/nodes=ubuntu2404_sharedlibs_withoutintl_x64/54468/console

19:12:10 not ok 3707 parallel/test-whatwg-encoding-custom-textdecoder
19:12:10   ---
19:12:10   duration_ms: 70.66700
19:12:10   severity: fail
19:12:10   exitcode: 1
19:12:10   stack: |-
19:12:10     node:internal/assert/utils:146
19:12:10       throw error;
19:12:10       ^
19:12:10     
19:12:10     AssertionError [ERR_ASSERTION]: Missing expected exception (TypeError).
19:12:10         at Object.<anonymous> (/home/iojs/build/workspace/node-test-commit-linux-containered/test/parallel/test-whatwg-encoding-custom-textdecoder.js:88:10)
19:12:10         at Module._compile (node:internal/modules/cjs/loader:1803:14)
19:12:10         at Object..js (node:internal/modules/cjs/loader:1934:10)
19:12:10         at Module.load (node:internal/modules/cjs/loader:1524:32)
19:12:10         at Module._load (node:internal/modules/cjs/loader:1326:12)
19:12:10         at TracingChannel.traceSync (node:diagnostics_channel:328:14)
19:12:10         at wrapModuleLoad (node:internal/modules/cjs/loader:245:24)
19:12:10         at Module.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:154:5)
19:12:10         at node:internal/main/run_main_module:33:47 {
19:12:10       generatedMessage: false,
19:12:10       code: 'ERR_ASSERTION',
19:12:10       actual: undefined,
19:12:10       expected: {
19:12:10         code: 'ERR_NO_ICU',
19:12:10         name: 'TypeError',
19:12:10         message: '"fatal" option is not supported on Node.js compiled without ICU'
19:12:10       },
19:12:10       operator: 'throws',
19:12:10       diff: 'simple'
19:12:10     }
19:12:10     
19:12:10     Node.js v26.0.0-pre
19:12:10   ...

[ChALkeR]

@richardlau indeed, I missed that, thanks! I'll update the test

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71041/