test(postage): nothing covers makescript's syncfiles deferral call site

defer_syncfiles_to_postboot has tests, but deleting the whole block out of
makescript -- the provmethod override and the call -- left the entire unit
suite green. That is precisely how the wrong deletion shipped two commits ago:
the override was removed on the mistaken grounds that %image_hash never carries
a provmethod, and nothing noticed.

makescript needs a management node and a database, so the block is lifted out
and eval'd into a scratch package, driven with the hash makescript actually
builds. What it pins is the resolution -- an osimage NAME becoming the
osimage's real provmethod -- and that the resolved value is what reaches the
helper.

Verified by mutation rather than by shape: an override that is present but
never fires reddens 1-3, and passing $provmethod instead of
$effective_provmethod reddens 2-3. Deleting the block, or the override, trips
the extraction guard instead, which is a loud failure rather than a silent
pass.

Signed-off-by: Daniel Hilst <392820+dhilst@users.noreply.github.com>

xCAT-test/unit/postage_makescript_defer_call_site.t

@@ -0,0 +1,122 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use File::Spec;
+use FindBin;
+use Test::More;
+
+# Regression: makescript's call to defer_syncfiles_to_postboot was covered by nothing.
+#
+# The helper itself has tests, but deleting the whole block out of makescript -- the
+# provmethod override AND the call -- left the entire unit suite green. That is how a wrong
+# deletion shipped once already: the override was removed on the mistaken grounds that
+# %image_hash never carries a provmethod, and no test noticed.
+#
+# makescript needs a management node and a database, so the block is lifted out and eval'd into
+# a scratch package, driven with the hash makescript actually builds. What is under test is the
+# resolution -- an osimage NAME becoming the osimage's real provmethod -- and that the result is
+# what reaches the helper.
+
+my $repo_root = File::Spec->rel2abs(
+    File::Spec->catdir( $FindBin::Bin, '..', '..' )
+);
+my $postage = File::Spec->catfile(
+    $repo_root, 'xCAT-server', 'lib', 'perl', 'xCAT', 'Postage.pm'
+);
+plan skip_all => "Postage.pm not found" unless -f $postage;
+
+my $src = do { local $/; open my $fh, '<', $postage or die $!; <$fh> };
+
+# The helper, and the block in makescript that calls it. BAIL_OUT rather than skip, so a rename
+# fails loudly instead of silently covering nothing.
+my ($helper) = $src =~ /\n(sub defer_syncfiles_to_postboot \{.*?\n\})\n/s;
+BAIL_OUT('could not extract defer_syncfiles_to_postboot from Postage.pm') unless defined $helper;
+
+my ($block) = $src =~ /\n([ ]+my \$effective_provmethod = \$provmethod;\n.*?defer_syncfiles_to_postboot\(\n.*?\);)\n/s;
+BAIL_OUT('could not extract the makescript call site from Postage.pm') unless defined $block;
+BAIL_OUT('the extracted call site does not consult the image hash')
+  unless $block =~ /\$image_hash\{\$osimgname\}\{'provmethod'\}/;
+
+my $driver = <<"CODE";
+$helper
+
+sub drive {
+    my (\%a) = \@_;
+    my \$provmethod   = \$a{provmethod};
+    my \$osimgname    = \$a{osimgname};
+    my \$os           = \$a{os};
+    my \$nodesetstate = \$a{nodesetstate};
+    my \$postscripts     = \$a{postscripts};
+    my \$postbootscripts = \$a{postbootscripts};
+    my \%image_hash = \%{ \$a{image_hash} || {} };
+$block
+    return (\$postscripts, \$postbootscripts, \$effective_provmethod);
+}
+CODE
+
+{
+    package T;
+    eval "$driver; 1" or main::BAIL_OUT("could not eval the makescript call site: $@");
+}
+
+my $POST = "otherpkgs\nsyncfiles\nremoteshell\n";
+
+# nodetype.provmethod naming an osimage: getScripts() fills %image_hash from the osimage table,
+# so the override is what turns that name into the real provmethod.
+{
+    my ($post, $postboot, $eff) = T::drive(
+        os => 'ubuntu24.04', nodesetstate => undef,
+        provmethod => 'ubuntu24.04-x86_64-install-compute',
+        osimgname  => 'ubuntu24.04-x86_64-install-compute',
+        image_hash => { 'ubuntu24.04-x86_64-install-compute' => { provmethod => 'install' } },
+        postscripts => $POST, postbootscripts => '' );
+    is( $eff, 'install', 'an osimage name resolves to the osimage provmethod' );
+    unlike( $post, qr/^syncfiles$/m, 'so syncfiles leaves the in-target postscripts' );
+    like( $postboot, qr/^syncfiles$/m, 'and is deferred to the postboot scripts' );
+}
+
+# Without the resolution there is nothing to key off when nodesetstate is absent.
+{
+    my ($post, $postboot, $eff) = T::drive(
+        os => 'ubuntu24.04', nodesetstate => undef,
+        provmethod => 'ubuntu24.04-x86_64-install-compute',
+        osimgname  => 'ubuntu24.04-x86_64-install-compute',
+        image_hash => {},
+        postscripts => $POST, postbootscripts => '' );
+    is( $eff, 'ubuntu24.04-x86_64-install-compute',
+        'an osimage with no row in the hash leaves the provmethod alone' );
+    like( $post, qr/^syncfiles$/m, 'and nothing is deferred' );
+}
+
+# A literal provmethod is passed straight through -- $osimgname is undef in that case.
+{
+    my ($post, $postboot, $eff) = T::drive(
+        os => 'ubuntu24.04', nodesetstate => undef, provmethod => 'install',
+        osimgname => undef, image_hash => {},
+        postscripts => $POST, postbootscripts => '' );
+    is( $eff, 'install', 'a literal provmethod is used as-is' );
+    unlike( $post, qr/^syncfiles$/m, 'and still defers' );
+}
+
+# nodesetstate wins when it is set, which is the ordinary nodeset path.
+{
+    my ($post, $postboot) = T::drive(
+        os => 'ubuntu24.04', nodesetstate => 'install',
+        provmethod => 'ubuntu24.04-x86_64-install-compute',
+        osimgname  => 'ubuntu24.04-x86_64-install-compute',
+        image_hash => {}, postscripts => $POST, postbootscripts => '' );
+    unlike( $post, qr/^syncfiles$/m, 'nodesetstate install defers regardless of provmethod' );
+    like( $postboot, qr/^syncfiles$/m, 'and syncfiles lands in the postboot scripts' );
+}
+
+# Not Ubuntu: the block must not touch anything.
+{
+    my ($post, $postboot) = T::drive(
+        os => 'rhels9', nodesetstate => 'install', provmethod => 'install',
+        osimgname => undef, image_hash => {}, postscripts => $POST, postbootscripts => '' );
+    like( $post, qr/^syncfiles$/m, 'a non-Debian OS keeps syncfiles where it was' );
+    is( $postboot, '', 'and gains no postboot scripts' );
+}
+
+done_testing();