I needed to make a couple of patches to REXML to fix this. The first patch
is because rcov passes Fixnums as attribute values, e.g.

       table_(:cellpadding => 0, :cellspacing => 0, :align => "right")

This could have been fixed at the rcov side, but since it *did* used to work
with rexml, I consider this a backwards-compatibility failure. The fix is
trivial:

--- rexml/text.rb.orig  2007-10-22 08:00:04.000000000 +0100
+++ rexml/text.rb       2007-10-22 08:00:33.000000000 +0100
@@ -286,7 +286,7 @@
     EREFERENCE = /&(?!#{Entity::NAME};)/
     # Escapes all possible entities
     def Text::normalize( input, doctype=nil, entity_filter=nil )
-      copy = input
+      copy = input.to_s
       # Doing it like this rather than in a loop improves the speed
       #copy = copy.gsub( EREFERENCE, '&' )
       copy = copy.gsub( "&", "&" )

(Note that there are other places in this file which might benefit from a
to_s as well)

The second is almost certainly a bug in REXML: it's a misnamed local
variable.

--- rexml/document.rb.orig      2007-10-22 08:02:36.000000000 +0100
+++ rexml/document.rb   2007-10-22 08:03:01.000000000 +0100
@@ -183,7 +183,7 @@
         output = Output.new( output, xml_decl.encoding )
       end
       formatter = if indent > -1
-          if transitive
+          if trans
             REXML::Formatters::Transitive.new( indent, ie_hack )
           else
             REXML::Formatters::Pretty.new( indent, ie_hack )

After these changes, rcov seems to run happily.

I wasn't sure where best to post this problem and its solution: ruby-core
(since REXML is in the ruby standard library), the REXML home site, or the
rcov home site. So I'm posting it here instead :-)

Regards,

Brian.

(*) The exception I saw initially was:

/usr/local/lib/ruby/1.8/rexml/text.rb:292:in `normalize': private method `gsub' called for 0:Fixnum (NoMethodError)
        from /usr/local/lib/ruby/1.8/rexml/element.rb:1084:in `[]='
        from /usr/local/lib/ruby/1.8/rexml/element.rb:586:in `add_attribute'
        from (eval):490:in `table_'
        from (eval):490:in `each'
        from (eval):490:in `table_'
        from (eval):490:in `each'
        from (eval):490:in `table_'
        from /usr/local/lib/ruby/gems/1.8/gems/rcov-0.8.0.2/lib/rcov/report.rb:702:in `format_overview'
         ... 61 levels...

After I fixed this by adding to_s in Text::normalize, I got

I can't see a fix for Fixnum attribute values though.

Regards,

After applying both fixes, I now get this:

/usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:131:in `[]': no
implicit conversion from nil to integer (TypeError)
        from /usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:131:in `wrap'
        from /usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:131:in `wrap'
        from /usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:90:in
`write_text'
        from /usr/local/lib/ruby/1.8/rexml/formatters/default.rb:50:in `write'
        from /usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:75:in
`write_element'
        from /usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:73:in `each'
        from /usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:73:in
`write_element'
        from /usr/local/lib/ruby/1.8/rexml/formatters/default.rb:31:in `write'
         ... 16 levels...

rcov outputs the index.html file and the first few controller files,
so I can trace it to which file it's getting choked on, but were there
any other fixes you had to put in?

Thanks,

Sean

On 10/22/07, Brian Candler <B.Cand...@pobox.com> wrote:

/usr/local/lib/ruby/1.8/rexml/formatters/pretty.rb:131:in `[]': no

On Oct 30, 6:09 pm, "Sean Hussey" <seanhus...@gmail.com> wrote:

...prefix.../ruby/gems/1.8/gems/rspec-1.0.8/lib/spec/rake/verify_rcov.rb
...prefix.../ruby/1.8/rexml/formatters/pretty.rb

Plus the files already patched by this point.  It seems like if your
stack trace says formatters/default.rb instead of formatters/pretty.rb
then that is the file you need to patch.

My formatters/pretty.rb patch looks like the following:

My rake/verify_rcov.rb patch looks like:

Hope that helps someone,
Susan

For the record, I'm running "rake test:functionals" on a Rails 2.1
project using:

ruby 1.8.7-p22 from Macports 1.600 on OS X (Tiger)
rcov 0.8.1.2.0

and getting the error:
/opt/local/lib/ruby/1.8/rexml/formatters/pretty.rb:131:in `[]': no
implicit conversion from nil to integer (TypeError)

until I applied the patch below to pretty.rb

Cant find the right file to modify to try that fix...

After doing the fix to:
...prefix.../ruby/1.8/rexml/formatters/pretty.rb
I am now getting this for an error:
572 tests, 115117 assertions, 0 failures, 0 errors
/usr/lib/ruby/1.8/rexml/formatters/pretty.rb:131:in `wrap': stack level
too deep (SystemStackError)
  from /usr/lib/ruby/1.8/rexml/formatters/pretty.rb:131:in `wrap'
  from /usr/lib/ruby/1.8/rexml/formatters/pretty.rb:90:in `write_text'
  from /usr/lib/ruby/1.8/rexml/formatters/default.rb:50:in `write'
  from /usr/lib/ruby/1.8/rexml/formatters/pretty.rb:75:in
`write_element'
  from /usr/lib/ruby/1.8/rexml/formatters/pretty.rb:73:in `each'
  from /usr/lib/ruby/1.8/rexml/formatters/pretty.rb:73:in
`write_element'
  from /usr/lib/ruby/1.8/rexml/formatters/default.rb:31:in `write'
  from /usr/lib/ruby/1.8/rexml/formatters/pretty.rb:75:in
`write_element'
   ... 12 levels...
  from /usr/lib/ruby/1.8/rcov.rb:628:in `each'
  from /usr/lib/ruby/1.8/rcov.rb:628:in `dump_coverage_info'
  from /usr/bin/rcov:405
  from /usr/lib/ruby/1.8/test/unit.rb:278

--- /opt/ruby-1.8.7-p72/lib/ruby/1.8/rexml/formatters/pretty.rb.OLD
2009-02-15 14:47:32.000000000 -0600
+++ /opt/ruby-1.8.7-p72/lib/ruby/1.8/rexml/formatters/pretty.rb
2009-02-15 14:48:50.000000000 -0600
@@ -126,10 +126,11 @@

       def wrap(string, width)
         # Recursively wrap string at width.
         return string if string.length <= width
         place = string.rindex(' ', width) # Position in string with
last ' ' before cutoff
+        return string if place.nil? # there aren't any ' 's before
cutoff, nothing to split on.
         return string[0,place] + "\n" + wrap(string[place+1..-1],
width)
       end

     end
   end

--- pretty.rb.old  2009-05-06 10:50:37.000000000 +1000
+++ pretty.rb  2009-05-06 10:55:37.000000000 +1000
@@ -128,6 +128,8 @@
         # Recursively wrap string at width.
         return string if string.length <= width
         place = string.rindex(' ', width) # Position in string with
last ' ' before cutoff
+        place = string.index(' ') if place.nil?
+        return string if place.nil? # there aren't any ' 's before
cutoff, nothing to split on.
         return string[0,place] + "\n" + wrap(string[place+1..-1],
width)
       end