src,tools: rewrite check-imports and fix linter errors

[thefourtheye]

Checklist

• tests and code linting passes
• the commit message follows commit guidelines

Affected core subsystem(s)

src, tools

Description of change

Commit 1

As it is, check-install.sh does not show more helpful error messages,
and supporting various shells could be a problem. This patch rewrites
the same in Python.

Commit 2

This patch simply enables check-imports.py in the linting process

Commit 3

Fix all the linter errors

---

cc @bnoordhuis

CI Run: https://ci.nodejs.org/job/node-test-pull-request/2210/

[Fishrock123]

concept seems good, can't comment on the python though

[bnoordhuis]

Can you use two-space indent in this file?

[thefourtheye]

@bnoordhuis Done!

[Fishrock123]

Looks like you missed one though, unless the CI is outdated.

File "src/handle_wrap.cc" does not use "Boolean"
Makefile:632: recipe for target 'cpplint' failed

[thefourtheye]

@Fishrock123 Hmmm, weird! I ran the linter locally before pushing. Anyway, I fixed it and the new CI Run (https://ci.nodejs.org/job/node-test-pull-request/2211/) completed linting successfully.

[bnoordhuis]

Can you remove the trailing blank line? Aside, you don't strictly need the square brackets in the line above but it doesn't hurt either.

[thefourtheye]

@bnoordhuis Actually, that is necessary. all and any short-circuit. They return True and False the moment they meet an item doesn't meet the criteria. Passing a generator expression will leave the rest of them unexecuted. For example,

>>>gen= (numfornuminxrange(10))
>>>all(item*item<20foritemingen)
False>>>list(gen)
[6, 7, 8, 9]

But when we use List Comprehension, it executes all of them and only their results are used with all and any. For example,

>>>gen= (numfornuminxrange(10))
>>>all([item*item<20foritemingen])
False>>>list(gen)
[]

Wrote more about it in this StackOverflow answer

[bnoordhuis]

LGTM with a style nit. I'm somewhat ambivalent about the rewrite to python, the new script is two or three times as long as the old one (if you exclude the copyright boilerplate.)

[thefourtheye]

@bnoordhuis The other reason I rewrote it in Python was because, if this is included in the linter, all the development environments are supposed to have sed, grep, sort and etc. That may not be available in all the environments I guess. I am okay with retaining the shell script itself, if possible.

[addaleax]

What would you think of using filename instead of file? I’d find that more a bit readable + it doesn’t shadow the file built-in.

[thefourtheye]

@addaleax I don't know how I missed that. Thanks for catching it :-) Fixed it now.

[thefourtheye]

As this patch adds a new linter task to the build process, ccing @nodejs/build

[thefourtheye]

If there are no objections, I'll land this in two days. cc @nodejs/collaborators

[indutny]

LGTM, finally!

[jasnell]

LGTM

[thefourtheye]

Landed in 2c480bd and 6781d91. Fixed one more linter error and a missed change from file to file_name.

[MylesBorins]

@thefourtheye should this be backported?

[thefourtheye]

@thealphanerd There is no harm in backporting this, but I am not sure if it is absolutely necessary :(

[MylesBorins]

@thefourtheye this does not land cleanly. I'm adding the dont-land label. Feel free to send a backport PR if you would like, but I don't see it as pressing