EmptyLines removes empty lines from heredoc strings

[ngan]

Not sure if this is a bug or feature, but the EmptyLines cop seems to not like blank lines in heredoc strings.

str = <<-TEXT
line 1


line 4
TEXT

[bbatsov]

I cannot reproduce this. What version of RuboCop are you using?

[ngan]

rubocop (0.18.1)

[ngan]

➜  cat test.rb 
str = <<-TEXT
line 1


line 2
TEXT
puts str

➜  rubocop test.rb 
Inspecting 1 file
C

Offences:

test.rb:4:1: C: Extra blank line detected.

1 file inspected, 1 offence detected

[bbatsov]

Ah, yes. Adding the puts after the heredoc triggers a false positive indeed. I'll have that fixed.

[bbatsov]

Seems that the tokens in the source are mixed up, which is causing the problem. The newline on the first line appear in the token stream just before the tokens of puts str. I'm not sure if this is a RuboCop bug or a Parser bug. @yujinakayama @jonas054 What do you think? Should we just sort the tokens by line number (which would solve this particular problem)?

[yujinakayama]

I guess this is not a Parser bug.

The @ngan's source:

str = <<-TEXT
line 1


line 2
TEXT
puts str

is tokenized as:

"str"      line:1 type:tIDENTIFIER
"="        line:1 type:tEQL
"<<\""     line:1 type:tSTRING_BEG
"line 1\n" line:2 type:tSTRING_CONTENT
"\n"       line:3 type:tSTRING_CONTENT
"\n"       line:4 type:tSTRING_CONTENT
"line 2\n" line:5 type:tSTRING_CONTENT
"TEXT"     line:6 type:tSTRING_END
nil        line:1 type:tNL             <- This causes the bug.
"puts"     line:7 type:tIDENTIFIER
"str"      line:7 type:tIDENTIFIER
nil        line:7 type:tNL

However, we can parenthesize heredocs like this:

puts(<<-TEXT)
line 1


line 2
TEXT
puts 'foo'

and its tokens are:

"puts"     line:1 type:tIDENTIFIER
"("        line:1 type:tLPAREN2
"<<\""     line:1 type:tSTRING_BEG
"line 1\n" line:2 type:tSTRING_CONTENT
"\n"       line:3 type:tSTRING_CONTENT
"\n"       line:4 type:tSTRING_CONTENT
"line 2\n" line:5 type:tSTRING_CONTENT
"TEXT"     line:6 type:tSTRING_END
")"        line:1 type:tRPAREN
nil        line:1 type:tNL
"puts"     line:7 type:tIDENTIFIER
"foo"      line:7 type:tSTRING
nil        line:7 type:tNL

I think this is natural order.

Should we just sort the tokens by line number (which would solve this particular problem)?

I think so. Or ignore line numbers that are less than the max line number seen so far.