Tests: replace usage of dlsym with separate modules containing functions that need to be mocked out

4 files changed, 95 insertions, 3 deletions

diff --git a/shm/dconf-shm-mockable.c b/shm/dconf-shm-mockable.c
new file mode 100644
index 0000000..6adf7d5
--- /dev/null
+++ b/shm/dconf-shm-mockable.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright © 2019 Daniel Playfair Cal
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Daniel Playfair Cal <daniel.playfair.cal@gmail.com>
+ */
+
+/**
+ * This module contains the production implementations of methods used in
+ * dconf_shm that need to be mocked out for tests.
+ *
+ * In some cases, external methods are wrapped with a different name. This is
+ * done so that it is not necessary to redefine the external functions in
+ * unit tests in order to mock them out, and therefore easy to also call the
+ * non mocked versions in tests if necessary.
+ */
+
+#include "config.h"
+
+#include "dconf-shm-mockable.h"
+
+#include <unistd.h>
+
+ssize_t
+dconf_shm_pwrite (int fd, const void *buf, size_t count, off_t offset)
+{
+  return pwrite (fd, buf, count, offset);
+}
diff --git a/shm/dconf-shm-mockable.h b/shm/dconf-shm-mockable.h
new file mode 100644
index 0000000..98ff33f
--- /dev/null
+++ b/shm/dconf-shm-mockable.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright © 2019 Daniel Playfair Cal
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Daniel Playfair Cal <daniel.playfair.cal@gmail.com>
+ */
+
+#ifndef __dconf_shm_mockable_h__
+#define __dconf_shm_mockable_h__
+
+#include <glib.h>
+
+G_GNUC_INTERNAL
+ssize_t                 dconf_shm_pwrite   (int          fd,
+                                            const void  *buf,
+                                            size_t       count,
+                                            off_t        offset);
+
+#endif /* __dconf_shm_mockable_h__ */
diff --git a/shm/dconf-shm.c b/shm/dconf-shm.c
index ae8c1c7..dbde759 100644
--- a/shm/dconf-shm.c
+++ b/shm/dconf-shm.c
@@ -21,6 +21,7 @@
 #include "config.h"
 
 #include "dconf-shm.h"
+#include "dconf-shm-mockable.h"
 
 #include <sys/mman.h>
 #include <unistd.h>
@@ -82,7 +83,7 @@ dconf_shm_open (const gchar *name)
    * By writing to the second byte in the file we ensure we don't
    * overwrite the first byte (which is the one we care about).
    */
-  if (pwrite (fd, "", 1, 1) != 1)
+  if (dconf_shm_pwrite (fd, "", 1, 1) != 1)
     {
       g_critical ("failed to allocate file '%s': %s.  dconf will not work properly.", filename, g_strerror (errno));
       goto out;
@@ -124,7 +125,7 @@ dconf_shm_flag (const gchar *name)
        * If this fails then it will probably fail for the client too.
        * If it doesn't then there's not really much we can do...
        */
-      if (pwrite (fd, "", 1, 1) == 1)
+      if (dconf_shm_pwrite (fd, "", 1, 1) == 1)
         {
           guint8 *shm;
 
diff --git a/shm/meson.build b/shm/meson.build
index 5fb9fe2..07f77d0 100644
--- a/shm/meson.build
+++ b/shm/meson.build
@@ -1,6 +1,11 @@
+sources = files(
+  'dconf-shm.c',
+  'dconf-shm-mockable.c',
+)
+
 libdconf_shm = static_library(
   'dconf-shm',
-  sources: 'dconf-shm.c',
+  sources: sources,
   include_directories: top_inc,
   dependencies: glib_dep,
   c_args: dconf_c_args,
@@ -11,3 +16,18 @@ libdconf_shm_dep = declare_dependency(
   dependencies: glib_dep,
   link_with: libdconf_shm,
 )
+
+
+libdconf_shm_test = static_library(
+  'dconf-shm-test',
+  sources: 'dconf-shm.c',
+  include_directories: top_inc,
+  dependencies: glib_dep,
+  c_args: dconf_c_args,
+  pic: true,
+)
+
+libdconf_shm_test_dep = declare_dependency(
+  dependencies: glib_dep,
+  link_with: libdconf_shm,
+)