child_process: refactor internal/child_process.js #11366
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lib/internal/child_process.js
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| stream.resume(); | ||
| }); | ||
| if (subprocess.stdio === null || subprocess.stdio === undefined) return; | ||
| for (let i = 0; i < subprocess.stdio.length; i++) { |
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Use var instead of let here for better backportability (let used in this way is still slower at least in v6.x and v4.x).
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This suggestion goes for all of the other occurrences below too.
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OK! Is there a guide on code style?
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@notarseniy make lint should have reported that issue. make lint is part of make test so if you ran tests, that should have come up as a lint error after the tests all passed. If the linter didn't report it, then there is probably a bug in our custom lint rule.
lib/internal/child_process.js
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| return; | ||
| stream.resume(); | ||
| }); | ||
| if (subprocess.stdio === null || subprocess.stdio === undefined) return; |
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I'm not sure this change is really worth it, the previous conditional is shorter and is equivalent in behavior.
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Motivation of this change was this line with 'that-style' condition.
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Well IMHO that other line could/should be changed to a non-strict equality check. The performance difference probably isn't measurable anymore.
lib/internal/child_process.js
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| }); | ||
| if (subprocess.stdio === null || subprocess.stdio === undefined) return; | ||
| for (let i = 0; i < subprocess.stdio.length; i++) { | ||
| if (!subprocess.stdio[i] || !subprocess.stdio[i].readable || subprocess.stdio[i]._readableState.readableListening) |
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Instead of looking up the value each time, add a temporary variable before the conditional. For example:
const stdio = subprocess.stdio;
for (var i = 0; i < stdio.length; ++i) {
const stream = stdio[i];
// .... keep rest of the code the same
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Yeah, sounds good. Will fix this
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Good comment. Will fix.
| @@ -800,7 +800,7 @@ function _validateStdio(stdio, sync) { | |||
| stdio = i < 3 ? 'pipe' : 'ignore'; | |||
| } | |||
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| if (stdio === null || stdio === 'ignore') { | |||
| if (stdio === 'ignore') { | |||
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Why this change? This would change behavior...
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In previous condition we're handling stdio === null, so this condition never will be executed with stdio === null
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Commited with fixes of comments. |
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More linting issues it seems. Run I'm guessing it's due to the duplicate |
lib/internal/child_process.js
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| return; | ||
| if (subprocess.stdio === null || subprocess.stdio === undefined) return; | ||
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| const stdio = subprocess.stdio; |
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This could probably be moved to the top of the function, where the first conditional can take advantage of it.
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* Prefer === to == where possible * Remove condition that will always be false * Prefer for-loop statements to forEach where possible for perfomance reasons
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CI is green. LGTM. |
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Bump! 😅 What the status of PR? Any other comments or additions? |
* Prefer === to == where possible * Remove condition that will always be false * Prefer for-loop statements to forEach where possible for perfomance reasons PR-URL: #11366 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Sam Roberts <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Brian White <[email protected]>
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@notarseniy I think it has just been forgotten. I went ahead and landed it in 8fc362e. Thanks for the contribution! |
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Thats okay :) Thank you too! |
* Prefer === to == where possible * Remove condition that will always be false * Prefer for-loop statements to forEach where possible for perfomance reasons PR-URL: #11366 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Sam Roberts <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Brian White <[email protected]>
* Prefer === to == where possible * Remove condition that will always be false * Prefer for-loop statements to forEach where possible for perfomance reasons PR-URL: #11366 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Sam Roberts <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Brian White <[email protected]>
* Prefer === to == where possible * Remove condition that will always be false * Prefer for-loop statements to forEach where possible for perfomance reasons PR-URL: #11366 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Sam Roberts <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Brian White <[email protected]>
* Prefer === to == where possible * Remove condition that will always be false * Prefer for-loop statements to forEach where possible for perfomance reasons PR-URL: #11366 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Sam Roberts <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Brian White <[email protected]>
* Prefer === to == where possible * Remove condition that will always be false * Prefer for-loop statements to forEach where possible for perfomance reasons PR-URL: #11366 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Sam Roberts <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Brian White <[email protected]>
Checklist
make -j4 test(UNIX), orvcbuild test(Windows) passesAffected core subsystem(s)
child_process