fs: make sure to write entire buffer

[atlowChemi]

fs.write(v) is not guaranteed to write everything in a single
call. Make sure we don't assume so.

Refs: #42434 (comment)

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53460/

[atlowChemi]

benchmark output:

                                                                                              confidence improvement accuracy (*)    (**)   (***)
fs/write-stream-throughput.js size=1024 encodingType='asc' dur=5                                             -0.97 %       ±2.40%  ±3.19%  ±4.15%
fs/write-stream-throughput.js size=1024 encodingType='buf' dur=5                                              0.81 %       ±1.53%  ±2.03%  ±2.65%
fs/write-stream-throughput.js size=1024 encodingType='utf' dur=5                                              1.61 %       ±1.75%  ±2.33%  ±3.06%
fs/write-stream-throughput.js size=1048576 encodingType='asc' dur=5                                           0.09 %       ±2.32%  ±3.09%  ±4.02%
fs/write-stream-throughput.js size=1048576 encodingType='buf' dur=5                                          -0.38 %       ±0.60%  ±0.80%  ±1.03%
fs/write-stream-throughput.js size=1048576 encodingType='utf' dur=5                                          -0.38 %       ±1.50%  ±1.99%  ±2.60%
fs/write-stream-throughput.js size=2 encodingType='asc' dur=5                                                -0.31 %       ±2.03%  ±2.71%  ±3.53%
fs/write-stream-throughput.js size=2 encodingType='buf' dur=5                                                -0.53 %       ±1.74%  ±2.32%  ±3.02%
fs/write-stream-throughput.js size=2 encodingType='utf' dur=5                                                -0.13 %       ±2.22%  ±2.96%  ±3.85%
fs/write-stream-throughput.js size=65535 encodingType='asc' dur=5                                     **     -1.64 %       ±1.05%  ±1.40%  ±1.85%
fs/write-stream-throughput.js size=65535 encodingType='buf' dur=5                                             0.09 %       ±1.02%  ±1.37%  ±1.80%
fs/write-stream-throughput.js size=65535 encodingType='utf' dur=5                                             0.06 %       ±1.18%  ±1.57%  ±2.04%


Be aware that when doing many comparisons the risk of a false-positive
result increases. In this case, there are 142 comparisons, you can thus
expect the following amount of false-positive results:
  7.10 false positives, when considering a   5% risk acceptance (*, **, ***),
  1.42 false positives, when considering a   1% risk acceptance (**, ***),
  0.14 false positives, when considering a 0.1% risk acceptance (***)

[ronag]

Existing tests pass and it's quite tricky make tests for this. You probably need to pass a custom "fs" implementation into the stream which will return EAGAIN.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53493/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53497/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53504/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53505/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53521/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53530/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/53534/

[atlowChemi]

Landed in feb5b0f