Handle repos passed as an array for list format

In 9876c31 the parameter repos was
changed to no longer allow an empty string. It does allow an array, but
that isn't specifically handled for the list format.

Fixes: 9876c31 ("Add support for deb822 APT sources (#1167)")

manifests/source.pp

@@ -139,6 +139,8 @@
 
       if $release =~ Pattern[/\/$/] {
         $_components = $_release
+      } elsif $repos =~ Array {
+        $_components = join([$_release] + $repos, ' ')
       } else {
         $_components = "${_release} ${repos}"
       }

spec/defines/source_spec.rb

@@ -36,6 +36,24 @@
       it {
         expect(subject).to contain_apt__setting('list-my_source').with(ensure: 'present').without_content(%r{# my_source\ndeb-src hello.there wheezy main\n})
       }
+
+      context 'with repos' do
+        context 'as empty array' do
+          let(:params) { super().merge(repos: []) }
+
+          it {
+            expect(subject).to contain_apt__setting('list-my_source').with(ensure: 'present').without_content(%r{# my_source\ndeb-src hello.there wheezy\n})
+          }
+        end
+
+        context 'as non-empty array' do
+          let(:params) { super().merge(repos: ['main', 'non-free', 'contrib']) }
+
+          it {
+            expect(subject).to contain_apt__setting('list-my_source').with(ensure: 'present').without_content(%r{# my_source\ndeb-src hello.there wheezy main non-free contrib\n})
+          }
+        end
+      end
     end
   end