Implement multiline attributes

[k0kubun]

Fixes #981.

This is ported from Hamlit v1 code which supported multiline attributes. It was dropped when Hamlit started using Haml's parser in v2, but I'd be happy to resurrect the support. Please read the code comments for design decision details.

[HamptonMakes]

Whoa... I didn't see this! @k0kubun– you... you.... <3

[kshnurov]

A simple %td{ title: 'asd' } asd'qwe fails with Old attributes must start with "{" and end with "}" because of that extra ' in the content. 5.2.0 works fine.
#1062

[k0kubun]

Sorry, I wasn't able to reproduce it. Could you prepare a repository that reproduces your issue? Thanks.

$ cat /tmp/a.haml
%td{ title: 'asd' } asd'qwe

$ ruby -v 
ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-darwin19]

$ haml -v
Haml 5.2.1

$ haml /tmp/a.haml
<td title='asd'>asd'qwe</td>

[kshnurov]

@k0kubun turns out it's a Ruby 2.4 issue. 2.5, 2.6, and 2.7 work fine.

$ cat ./a.html
%td{ title: 'asd' } asd'qwe

$ ruby -v
ruby 2.4.10p364 (2020-03-31 revision 67879) [x86_64-darwin18]

$ haml -v
Haml 5.2.1

$ haml ./a.html
Exception on line 219: Old attributes must start with "{" and end with "}"
  Use --trace for backtrace.

[k0kubun]

Yeah, it seems like a bug of Ripper (a part of Ruby). The problem is that the parser reorders tokens in edge cases like that, and it's a bit hard to implement a fix on Haml's side. Thus the bug report should go to ruby-core, instead of this haml repository.

$ ruby -v -rripper -e "puts Ripper.lex(%q[a( b: 'c' } d'e]).map{|x| x[2]}.join"
ruby 2.4.9p362 (2019-10-02 revision 67824) [x86_64-darwin18]
ea( b: 'c' } d'

$  ruby -v -rripper -e "puts Ripper.lex(%q[a( b: 'c' } d'e]).map{|x| x[2]}.join"
ruby 2.5.8p224 (2020-03-31 revision 67882) [x86_64-darwin19]
a( b: 'c' } d'e

JFYI, 2.3 also works fine. 2.2 and older have the bug, like 2.4.

$ ruby -v -rripper -e "puts Ripper.lex(%q[a( b: 'c' } d'e]).map{|x| x[2]}.join"
ruby 2.3.8p459 (2018-10-18 revision 65136) [x86_64-darwin18]
a( b: 'c' } d'e

[kshnurov]

@k0kubun 2.4 is EOL so there won't be a fix. Maybe it's time for HAML to drop Ruby 2.4- compatibility? @hcatlin

[HamptonMakes]

@kshnurov what would that mean to you? We only test against Ruby 2.7+, and I wouldn't think we should error unless necessary.

[kshnurov]

@hcatlin README says Haml currently supports Ruby 2.0.0 and higher. I guess Ruby 2.4- users shouldn't be confused and upgrade to the latest versions of Haml.

[k0kubun]

We only test against Ruby 2.7+

Sorry for confusing you maybe by leaving a premature GitHub Actions config, but we currently test 2.5+ in Travis

haml/.travis.yml

Lines 9 to 10 in d3839d3

	- 2.6
	- 2.5

If we want to clarify the supported versions,

haml/haml.gemspec

Line 26 in d3839d3

spec.required_ruby_version = '>= 2.0.0'

would be the best place to do so. (Of course we should update README as well like @kshnurov said)

[HamptonMakes]

Thanks for the clarification everyone.