[tracker/sam/functional-tests-quiet: 10/15] trackertestutils: Rewrite dconf client to call `gsettings` directly

[Sam Thursfield <sthursfield src gnome org>]

commit 3e5640f29bb6e1be95c19f4e2b658b207f55150e
Author: Sam Thursfield <sam afuera me uk>
Date:   Sat Aug 31 03:23:09 2019 +0300

    trackertestutils: Rewrite dconf client to call `gsettings` directly
    
    This is needed because we no longer set DCONF_PROFILE in the test
    process environment, we only set it in the environment of the Tracker
    daemons under test.

 utils/trackertestutils/dconf.py | 68 +++++++++++------------------------------
 1 file changed, 18 insertions(+), 50 deletions(-)
---
diff --git a/utils/trackertestutils/dconf.py b/utils/trackertestutils/dconf.py
index 4ad0e88e9..de9da19df 100644
--- a/utils/trackertestutils/dconf.py
+++ b/utils/trackertestutils/dconf.py
@@ -18,11 +18,9 @@
 # 02110-1301, USA.
 #
 
-from gi.repository import GLib
-from gi.repository import Gio
-
 import logging
 import os
+import subprocess
 
 log = logging.getLogger(__name__)
 
@@ -36,28 +34,22 @@ class DConfClient(object):
     this reason, and the constructor will fail if this isn't the profile in
     use, to avoid any risk of modifying or removing your real configuration.
 
-    The constructor will fail if DConf is not the default backend, because this
-    probably indicates that the memory backend is in use. Without DConf the
-    required configuration changes will not take effect, causing many tests to
-    break.
+    We use the `gsettings` binary rather than using the Gio.Settings API.
+    This is to avoid the need to set DCONF_PROFILE in our own process
+    environment.
     """
 
-    def __init__(self, schema):
-        self._settings = Gio.Settings.new(schema)
-
-        backend = self._settings.get_property('backend')
-        self._check_settings_backend_is_dconf(backend)
-        self._check_using_correct_dconf_profile()
-
-    def _check_settings_backend_is_dconf(self, backend):
-        typename = type(backend).__name__.split('.')[-1]
-        if typename != 'DConfSettingsBackend':
-            raise Exception(
-                "The functional tests require DConf to be the default "
-                "GSettings backend. Got %s instead." % typename)
+    def __init__(self, extra_env):
+        self.env = os.environ
+        self.env.update(extra_env)
 
     def _check_using_correct_dconf_profile(self):
-        profile = os.environ["DCONF_PROFILE"]
+        profile = self.env.get("DCONF_PROFILE")
+        if not profile:
+            raise Exception(
+                "DCONF_PROFILE is not set in the environment. This class must "
+                "be created inside a TrackerDBussandbox to avoid risk of "
+                "interfering with real settings.")
         if not os.path.exists(profile):
             raise Exception(
                 "Unable to find DConf profile '%s'. Check that Tracker and "
@@ -66,35 +58,11 @@ class DConfClient(object):
 
         assert os.path.basename(profile) == "trackertest"
 
-    def write(self, key, value):
+    def write(self, schema, key, value):
         """
         Write a settings value.
         """
-        self._settings.set_value(key, value)
-
-    def read(self, schema, key):
-        """
-        Read a settings value.
-        """
-        return self._settings.get_value(key)
-
-    def reset(self):
-        """
-        Remove all stored values, resetting configuration to the default.
-
-        This can be done by removing the entire 'trackertest' configuration
-        database.
-        """
-
-        self._check_using_correct_dconf_profile()
-
-        # XDG_CONFIG_HOME is useless, so we use HOME. This code should not be
-        # needed unless for some reason the test is not being run via the
-        # 'test-runner.sh' script.
-        dconf_db = os.path.join(os.environ["HOME"],
-                                ".config",
-                                "dconf",
-                                "trackertest")
-        if os.path.exists(dconf_db):
-            log.debug("[Conf] Removing dconf database: %s", dconf_db)
-            os.remove(dconf_db)
+        subprocess.run(['gsettings', 'set', schema, key, value.print_(False)],
+                       env=self.env,
+                       stdout=subprocess.PIPE,
+                       stderr=subprocess.PIPE)