test(xcat-core): go-xcat complete uninstall skips packages with config files left

After `apt-get remove`, dpkg reports a package as "deinstall ok
config-files". uninstall_xcat_completely() selects packages with
installed_packages(), which accepts only "install ok installed". A
complete uninstall after an ordinary uninstall therefore does not purge
the xCAT packages, and their configuration files stay on the node.

The new bats test runs both uninstall paths against a dpkg-query stub.
The two purge tests fail on this tree. The ordinary uninstall keeps its
installed-only filter.

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

xCAT-test/bats/go_xcat_uninstall_config_files.bats

@@ -0,0 +1,67 @@
+#!/usr/bin/env bats
+#
+# `apt-get remove` leaves a package in the "deinstall ok config-files" state (dpkg `rc`).
+# `go-xcat uninstall` removes, so it skips those. `go-xcat uninstall --completely` purges,
+# so it must include them, or a remove followed by a complete uninstall leaves the
+# configuration files behind.
+#
+# go-xcat is sourced. dpkg-query and the package, kill and trash steps are shell functions
+# here, and PATH is empty, so no test reads or changes the host package database or files.
+
+load 'helpers/go_xcat'
+
+setup()
+{
+    go_xcat_require_source
+    # shellcheck disable=SC1090
+    source "$GO_XCAT_SOURCE"
+    remove_package() { printf 'remove %s\n' "$@"; }
+    purge_package() { printf 'purge %s\n' "$@"; }
+    kill_xcat() { :; }
+    trash_xcat() { :; }
+    # The state dpkg reports after `apt-get remove xcat-test-removed`.
+    dpkg-query()
+    {
+        case "$3" in
+        xcat-test-installed) printf 'install ok installed' ;;
+        xcat-test-removed) printf 'deinstall ok config-files' ;;
+        *) return 1 ;;
+        esac
+    }
+    GO_XCAT_UNINSTALL_LIST=(xcat-test-absent xcat-test-installed xcat-test-removed)
+}
+
+without_path()
+{
+    local PATH=""
+    "$@"
+}
+
+@test "deb: complete uninstall purges packages that only have configuration files left" {
+    run without_path uninstall_xcat_completely
+    [ "$status" -eq 0 ]
+    [ "$output" = "purge -y
+purge xcat-test-installed
+purge xcat-test-removed" ]
+}
+
+@test "deb: complete uninstall after a remove purges the removed package" {
+    GO_XCAT_UNINSTALL_LIST=(xcat-test-absent xcat-test-removed)
+    run without_path uninstall_xcat_completely
+    [ "$status" -eq 0 ]
+    [ "$output" = "purge -y
+purge xcat-test-removed" ]
+}
+
+@test "deb: ordinary uninstall removes only the installed packages" {
+    run without_path uninstall_xcat -y
+    [ "$status" -eq 0 ]
+    [ "$output" = "remove -y
+remove xcat-test-installed" ]
+}
+
+@test "deb: a package with only configuration files left is not reported as installed" {
+    run without_path installed_packages xcat-test-removed xcat-test-installed
+    [ "$status" -eq 0 ]
+    [ "$output" = "xcat-test-installed" ]
+}