* gnu/tests/reconfigure.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
---
 gnu/local.mk              |  1 +
 gnu/tests/reconfigure.scm | 99 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)
 create mode 100644 gnu/tests/reconfigure.scm

diff --git a/gnu/local.mk b/gnu/local.mk
index 0e17af953..b334d0572 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -592,6 +592,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/tests/mail.scm				\
   %D%/tests/messaging.scm			\
   %D%/tests/networking.scm			\
+  %D%/tests/reconfigure.scm			\
   %D%/tests/rsync.scm				\
   %D%/tests/security-token.scm			\
   %D%/tests/singularity.scm			\
diff --git a/gnu/tests/reconfigure.scm b/gnu/tests/reconfigure.scm
new file mode 100644
index 000000000..bb8c33bf5
--- /dev/null
+++ b/gnu/tests/reconfigure.scm
@@ -0,0 +1,99 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2019 Jakob L. Kreuze <zerodaysfordays@sdf.lonestar.org>
+;;;
+;;; 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 (gnu tests reconfigure)
+  #:use-module (gnu tests)
+  #:use-module (gnu system)
+  #:use-module (gnu system vm)
+  #:use-module (gnu services)
+  #:use-module (gnu services networking)
+  #:use-module (gnu services shepherd)
+  #:use-module (guix derivations)
+  #:use-module (guix gexp)
+  #:use-module (guix monads)
+  #:use-module (guix scripts system reconfigure)
+  #:use-module (guix store)
+  #:export (%test-switch-to-system))
+
+;;; Commentary:
+;;;
+;;; Test in-place system reconfiguration: advancing the system generation on a
+;;; running instance of the Guix System.
+;;;
+;;; Code:
+
+(define* (run-switch-to-system-test)
+  "Run a test of an OS running SWITCH-SYSTEM-PROGRAM, which creates a new
+generation of the system profile."
+  (define os
+    (marionette-operating-system
+     (simple-operating-system)
+     #:imported-modules '((gnu services herd)
+                          (guix combinators))))
+
+  (define vm (virtual-machine os))
+
+  (define (test script)
+    (with-imported-modules '((gnu build marionette))
+      #~(begin
+          (use-modules (gnu build marionette)
+                       (srfi srfi-64))
+
+          (define marionette
+            (make-marionette (list #$vm)))
+
+          (define (system-generations marionette)
+            "Return the names of the generation symlinks on MARIONETTE."
+            (marionette-eval
+             '(begin
+                (use-modules (ice-9 ftw)
+                             (srfi srfi-1))
+                (let* ((profile-dir "/var/guix/profiles/")
+                       (entries (map first (cddr (file-system-tree profile-dir)))))
+                  (remove (lambda (entry)
+                            (member entry '("per-user" "system")))
+                          entries)))
+             marionette))
+
+          (mkdir #$output)
+          (chdir #$output)
+
+          (test-begin "switch-to-system")
+
+          (let ((generations-prior (system-generations marionette)))
+            (test-assert "capture activation script output"
+              (string?
+               (marionette-eval
+                '(primitive-load #$script)
+                marionette)))
+
+            (test-equal "deployment created new generation"
+              (length (system-generations marionette))
+              (1+ (length generations-prior))))
+
+          (test-end)
+          (exit (= (test-runner-fail-count (test-runner-current)) 0)))))
+
+  (mlet %store-monad ((script (switch-system-program os)))
+    (gexp->derivation "switch-to-system" (test script))))
+
+(define %test-switch-to-system
+  (system-test
+   (name "switch-to-system")
+   (description "Create a new generation of the system profile.")
+   (value (run-switch-to-system-test))))
-- 
2.22.0