io: introduce write_file helper sub

This is pretty convenient way to create files for diff
generation in both WWW and lei.  The test suite should also be
able to take advantage of it.

1 files changed, 3 insertions, 6 deletions

diff --git a/lib/PublicInbox/LeiRediff.pm b/lib/PublicInbox/LeiRediff.pm
index fdff4b4b..35728330 100644
--- a/lib/PublicInbox/LeiRediff.pm
+++ b/lib/PublicInbox/LeiRediff.pm
@@ -114,12 +114,9 @@ EOM
         if (!$rw->{-tmp}) {
                 my $d = "$self->{rdtmp}/for_tree.git";
                 -d $d or PublicInbox::Import::init_bare($d);
-                my $f = "$d/objects/info/alternates"; # always overwrite
-                open my $fh, '>', $f or die "open $f: $!";
-                for my $git (@{$self->{gits}}) {
-                        print $fh $git->git_path('objects'),"\n";
-                }
-                close $fh or die "close $f: $!";
+                # always overwrite
+                PublicInbox::IO::write_file '>', "$d/objects/info/alternates",
+                        map { $_->git_path('objects')."\n" } @{$self->{gits}};
                 $rw = PublicInbox::Git->new($d);
         }
         my $w = popen_wr(['git', "--git-dir=$rw->{git_dir}",