2 empty lines geneated in a template

[junaruga]

The current gem2rpm creates 2 empty lines between cp -a and mkdir -p for a generated spec file.

As a result on the following PR line 13, the 2 lines is changed to 1 line.
https://src.fedoraproject.org/rpms/rubygem-rack/pull-request/3#request_diff

1 empty line is better for the template than 2 empty lines, isn't it?

Here is the log for rubygem-rack.

$ which gem2rpm
/usr/bin/gem2rpm

$ rpm -qf /usr/bin/gem2rpm
rubygem-gem2rpm-1.0.1-6.fc33.noarch

$ gem2rpm rack-2.2.3.gem > rubygem-rack.spec.new

$ cat rubygem-rack.spec.new
...
%install
mkdir -p %{buildroot}%{gem_dir}
cp -a .%{gem_dir}/* \
        %{buildroot}%{gem_dir}/


mkdir -p %{buildroot}%{_bindir}
cp -a .%{_bindir}/* \
        %{buildroot}%{_bindir}/
...

[voxik]

1. I don't personally mind the spaces. Admittedly, in this specific case, it would be probably better if they are gone.
2. I am afraid this is not as easy to solve. If you check the template, there are not additional empty lines spaces:
   

   gem2rpm/templates/fedora-27-rawhide.spec.erb

   Lines 56 to 74 in 4783f1b

   	%install
   	mkdir -p %{buildroot}%{gem_dir}
   	cp -a .%{gem_dir}/* \
   	%{buildroot}%{gem_dir}/
   	<% unless spec.extensions.empty? -%>
   	mkdir -p %{buildroot}%{gem_extdir_mri}
   	cp -a .%{gem_extdir_mri}/{gem.build_complete,*.so} %{buildroot}%{gem_extdir_mri}/
   	<% for ext in spec.extensions -%>
   	# Prevent dangling symlink in -debuginfo (rhbz#878863).
   	rm -rf %{buildroot}%{gem_instdir}/<%= ext.split(File::SEPARATOR).first %>/
   	<% end -%>
   	<% end -%>
   	<% unless spec.executables.empty? -%>
   	mkdir -p %{buildroot}%{_bindir}
   	cp -a .%{_bindir}/* \
   	%{buildroot}%{_bindir}/

   
   The problem is that the template tags are expanded into empty lines and AFAIK, using ERB, there is no way to get easily rid of them. In theory they could be remove for the price of worse template readability, what is not win either.

[pvalena]

You're right, if we stick to this formatting.

The lines 60 and 70 are responsible for the double space. Could be resolved by writing it like so. f.e.:

mkdir -p %{buildroot}%{gem_dir}
cp -a .%{gem_dir}/* \
        %{buildroot}%{gem_dir}/
<%
unless spec.extensions.empty? -%>

Or any other adjustment which changes one of those empty lines to either end with -%> or start with <%.

[junaruga]

The problem is that the template tags are expanded into empty lines and AFAIK, using ERB, there is no way to get easily rid of them. In theory they could be remove for the price of worse template readability, what is not win either.

I do not think so. You can see https://puppet.com/docs/puppet/5.5/lang_template_erb.html . -%> trims 1 line break after -%>. I see the reason is simply how to write the template is not correct. I sent a PR.

-%> — If the tag ends a line, trim the following line break.