Bug #1559

ERB single line comment does not work

Added by James Zhang over 2 years ago. Updated 10 months ago.

[ruby-core:23682]
Status:Rejected Start date:06/03/2009
Priority:Normal Due date:
Assignee:Masatoshi Seki % Done:

0%
Category:-
Target version:1.9.1
ruby -v:ruby 1.9.1p129 (2009-05-12 revision 23412) [i386-darwin9.7.0]

Description

In erb you're supposed to be able to do single line comments:

<% # this is a comment %>

However, this does not work in ruby 1.9.1.

Temporary work around is to put the '%>' on a newline:

<% # this comment works in 1.9.1
%>

Please see attached unit test.

test_erb.rb - test that passes in Ruby 1.8.6 but fails in Ruby 1.9.1 (313 Bytes) James Zhang, 06/03/2009 01:19 pm

Related issues

duplicated by ruby-trunk - Bug #3146: ERB single line comment does not work Rejected 04/14/2010

History

#1
Updated by Jeremy Kemper over 2 years ago

<%# this comment (no space between % and #) works in 1.9.1 %>

I think <% # (with a space) was a side effect not a feature.

#2
Updated by Yuki Sonoda over 2 years ago

  • Assignee set to Masatoshi Seki

#3
Updated by Johannes Fahrenkrug over 2 years ago

Hi, 

I just ran into this issue on ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux] as well. The test_erb.rb test fails.
On ruby 1.8.6 (2008-08-11 patchlevel 287) [universal-darwin9.0], however, it passes.

- Johannes

#4
Updated by khaled alhabache over 2 years ago

This bug is somehow annoying specially when u move from ruby 1.8.6 to either 1.8.7 or 1.9 and working with rails, many comments in views files.....

#5
Updated by Robin Salkeld almost 2 years ago

This seems to be caused by removing \n from the regular expressions used in ERB::Compiler::SimpleScanner2:

stag_reg = /(.*?)(<%%|<%=|<%#|<%|\z)/m
etag_reg = /(.*?)(%%>|%>|\z)/m

It looks like the original change was intended as an optimization, but unintentionally changed the behaviour. Restoring the \n's fixes it.

<%# may work for comments as well, but a lot of us have relied on the old behaviour, and I see no reason not to fix an accidental regression.

#6
Updated by Yusuke Endoh almost 2 years ago

  • Status changed from Open to Rejected
Hi,

The maintainer of erb (Masatoshi Seki) formally rejected this
ticket in [ruby-dev:40990].

Use <%# ... %>.

-- 
Yusuke Endoh <mame@tsg.ne.jp>

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