services: Add lightdm-service-type.

* gnu/services/lightdm.scm: New service.
* tests/services/lightdm.scm: Test it.
* doc/guix.texi (X Window): Document it.
* gnu/local.mk (GNU_SYSTEM_MODULES): Register it.

Co-authored-by: L p R n d n <guix@lprndn.info>
Co-authored-by: Ricardo Wurmus <rekado@elephly.net>

1 files changed, 52 insertions, 0 deletions

diff --git a/tests/services/lightdm.scm b/tests/services/lightdm.scm
new file mode 100644
index 00000000000..283df2befc4
--- /dev/null
+++ b/tests/services/lightdm.scm
@@ -0,0 +1,52 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (tests services lightdm)
+  #:use-module (guix diagnostics)
+  #:use-module (gnu services lightdm)
+  #:use-module (srfi srfi-64))
+
+;;; Tests for the (gnu services lightdm) module.
+
+;;; Access some internals for whitebox testing.
+(define validate-lightdm-configuration (@@ (gnu services lightdm)
+                                           validate-lightdm-configuration))
+
+(test-begin "lightdm-service")
+
+(test-equal "error on missing greeter"
+  'ok
+  (catch 'quit
+    (lambda ()
+      (validate-lightdm-configuration (lightdm-configuration (greeters '()))))
+    (lambda _
+      'ok)))
+
+(test-equal "error when a greeter has multiple configurations"
+  'ok
+  (catch 'quit
+    (lambda ()
+      (lightdm-configuration
+       (greeters (list (lightdm-gtk-greeter-configuration
+                        (theme-name "boring"))
+                       (lightdm-gtk-greeter-configuration
+                        (theme-name "blue"))))))
+    (lambda _
+      'ok)))
+
+(test-end "lightdm-service")