Regex to convert JSDoc from coffeescript to javascript - perl

Question

I'm trying to convert a project from coffeescript to javascript. I've successfully used the decaffeinate tool but something remains boring to convert manually: JSdoc comments
In coffescript we took the habit to write them like using the formalism of this example:
##
# This will remove the given file from the machine attachments list. If the file was previously uploaded
# to the server, it will be marked for deletion on the server. Otherwise, it will be simply truncated from
# the attachments array.
# #param file {Object} the file to delete
# #returns {boolean}
##
After using decaffeinate, they were transformed to something like that:
// #
// This will remove the given file from the machine attachments list. If the file was previously uploaded
// to the server, it will be marked for deletion on the server. Otherwise, it will be simply truncated from
// the attachments array.
// #param file {Object} the file to delete
// #returns {boolean}
// #
So I've tried to write a perl regex to make them look like the standard JSdoc syntax. But I'm stuck with the central lines: I can't find to way to put a star at the beginning of each lines ... Here's the best I've came to:
find . -type f -name "*.js" | xargs perl -0777 -i -pe 's~// #\n( +// (.+\n)+)( +)// #~/**\n$1$3 */~gm;'
Which results in:
/**
// This will remove the given file from the machine attachments list. If the file was previously uploaded
// to the server, it will be marked for deletion on the server. Otherwise, it will be simply truncated from
// the attachments array.
// #param file {Object} the file to delete
// #returns {boolean}
*/
But ideally, it should be transformed to:
/**
* This will remove the given file from the machine attachments list. If the file was previously uploaded
* to the server, it will be marked for deletion on the server. Otherwise, it will be simply truncated from
* the attachments array.
* #param file {Object} the file to delete
* #returns {boolean}
*/
Here's an example of a complete file to transform: https://gist.github.com/sylvainbx/96e53b879b4dd7ef7cdd153c3fc3c5b8
Any help would be appreciated :)

Answer 1

You can't easily do this within a single regular expression, as you need to capture and replace the first // # differently from the second // #. The following script shows how you can call a subroutine on the right hand side of the replacement and in that subroutine, you can use three simple regular expressions to convert your comment to JSdoc:
#!perl
use strict;
use warnings;
my $js = <<'JS';
foo
// #
// This will remove the given file from the machine attachments list. If the file was previously uploaded
// to the server, it will be marked for deletion on the server. Otherwise, it will be simply truncated from
// the attachments array.
// #param file {Object} the file to delete
// #returns {boolean}
// #
// # List of trainings
bar
JS
sub uncomment {
my($doc) = #_;
$doc =~ s!^// #!/*!;
$doc =~ s!// #$! */!;
$doc =~ s!^//( #)?! $1 ||'' eq '#' ? '/*' : ' *' !gme;
warn $doc;
$doc
}
$js =~ s!(// #\R// (.+\n)+( *)// #\R)!uncomment($1)!gme;
print $js;
Converted to a stand-alone document-to-JSdoc pipe, the following works:
#!perl
use strict;
use warnings;
local $/;
my $js = <>;
sub uncomment {
my($doc) = #_;
$doc =~ s!^// #!/*!;
$doc =~ s!// #$! */!;
$doc =~ s!^//( #)?! $1 ||'' eq '#' ? '/*' : ' *' !gme;
warn $doc;
$doc
}
$js =~ s!(// #\R// (.+?\n)+( *)// #\R)!uncomment($1)!gme;
print $js;