Fix evaluation priority of the bootstrap settings

Closes GitLab issue #702. Thanks to Kevin Pawsey (@kevinpawsey) for
the report and the help debuging the issue.

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

HISTORY.rst

@@ -15,6 +15,9 @@
   mark widget.
 - Add icons to the smart settings links.
 - Fix docker-runtest-all target.
+- Fix the evaluation priority of the bootstrap settings. Closes GitLab issue
+  #702. Thanks to Kevin Pawsey (@kevinpawsey) for the report and the help
+  debuging the issue.
 
 3.3.3 (2019-12-05)
 ==================

mayan/apps/smart_settings/tests/literals.py

@@ -3,6 +3,8 @@ from __future__ import unicode_literals
 ENVIRONMENT_TEST_NAME = 'PAGINATE_BY'
 ENVIRONMENT_TEST_VALUE = '999999'
 
+TEST_BOOTSTAP_SETTING_NAME = 'TEST_BOOTSTRAP_SETTING'
+
 TEST_NAMESPACE_LABEL = 'test namespace label'
 TEST_NAMESPACE_NAME = 'test_namespace_name'
 
@@ -10,3 +12,4 @@ TEST_SETTING_GLOBAL_NAME = 'SMART_SETTINGS_TEST_SETTING'
 TEST_SETTING_INITIAL_VALUE = 'test_setting_initial_value'
 TEST_SETTING_DEFAULT_VALUE = 'test_setting_default_value'
 TEST_SETTING_VALUE = 'test_setting_value'
+TEST_SETTING_VALUE_OVERRIDE = 'test value override'

mayan/apps/smart_settings/tests/mixins.py

@@ -1,13 +1,52 @@
 from __future__ import absolute_import, unicode_literals
 
+from django.utils.encoding import force_bytes
+
+from mayan.apps.storage.utils import NamedTemporaryFile
+
 from ..classes import Namespace
+from ..utils import BaseSetting, SettingNamespaceSingleton
 
 from .literals import (
-    TEST_NAMESPACE_LABEL, TEST_NAMESPACE_NAME, TEST_SETTING_DEFAULT_VALUE,
-    TEST_SETTING_GLOBAL_NAME
+    TEST_BOOTSTAP_SETTING_NAME, TEST_NAMESPACE_LABEL, TEST_NAMESPACE_NAME,
+    TEST_SETTING_DEFAULT_VALUE, TEST_SETTING_GLOBAL_NAME
 )
 
 
+class BoostrapSettingTestMixin(object):
+    def _create_test_bootstrap_singleton(self):
+        self.test_globals = {}
+        self.test_globals['BASE_DIR'] = ''
+        self.setting_namespace = SettingNamespaceSingleton(
+            global_symbol_table=self.test_globals
+        )
+
+    def _create_test_config_file(self, value):
+        with NamedTemporaryFile() as file_object:
+            self._set_environment_variable(
+                name='MAYAN_CONFIGURATION_FILEPATH',
+                value=file_object.name
+            )
+
+            file_object.write(
+                force_bytes(
+                    '{}: {}'.format(
+                        TEST_BOOTSTAP_SETTING_NAME, value
+                    )
+                )
+            )
+            file_object.seek(0)
+
+            self.setting_namespace.update_globals()
+
+    def _register_test_boostrap_setting(self):
+        SettingNamespaceSingleton.register_setting(
+            name=TEST_BOOTSTAP_SETTING_NAME, klass=BaseSetting, kwargs={
+                'has_default': True, 'default_value': 'value default'
+            }
+        )
+
+
 class SmartSettingsTestCaseMixin(object):
     def setUp(self):
         super(SmartSettingsTestCaseMixin, self).setUp()

mayan/apps/smart_settings/tests/test_utils.py

@@ -0,0 +1,61 @@
+from __future__ import absolute_import, unicode_literals
+
+from mayan.apps.common.tests.base import BaseTestCase
+from mayan.apps.common.tests.mixins import EnvironmentTestCaseMixin
+
+from .literals import (
+    TEST_BOOTSTAP_SETTING_NAME, TEST_SETTING_VALUE,
+    TEST_SETTING_VALUE_OVERRIDE
+)
+from .mixins import BoostrapSettingTestMixin
+
+
+class BoostrapSettingTestCase(
+    BoostrapSettingTestMixin, EnvironmentTestCaseMixin, BaseTestCase
+):
+    def setUp(self):
+        super(BoostrapSettingTestCase, self).setUp()
+        self._register_test_boostrap_setting()
+        self._create_test_bootstrap_singleton()
+
+    def test_bootstrap_environment_overrides_config(self):
+        self._set_environment_variable(
+            name='MAYAN_{}'.format(TEST_BOOTSTAP_SETTING_NAME),
+            value=TEST_SETTING_VALUE_OVERRIDE
+        )
+
+        self._create_test_config_file(value=TEST_SETTING_VALUE)
+
+        self.assertEqual(
+            self.test_globals[TEST_BOOTSTAP_SETTING_NAME],
+            TEST_SETTING_VALUE_OVERRIDE
+        )
+
+    def test_bootstrap_config_overrides_settings(self):
+        self.test_globals[TEST_BOOTSTAP_SETTING_NAME] = TEST_SETTING_VALUE
+
+        self._create_test_config_file(value=TEST_SETTING_VALUE_OVERRIDE)
+
+        self.assertEqual(
+            self.test_globals[TEST_BOOTSTAP_SETTING_NAME],
+            TEST_SETTING_VALUE_OVERRIDE
+        )
+
+    def test_bootstrap_settings_overrides_default(self):
+        self.test_globals[
+            TEST_BOOTSTAP_SETTING_NAME
+        ] = TEST_SETTING_VALUE_OVERRIDE
+
+        self.setting_namespace.update_globals()
+
+        self.assertEqual(
+            self.test_globals[TEST_BOOTSTAP_SETTING_NAME],
+            TEST_SETTING_VALUE_OVERRIDE
+        )
+
+    def test_bootstrap_default(self):
+        self.setting_namespace.update_globals()
+
+        self.assertEqual(
+            self.test_globals[TEST_BOOTSTAP_SETTING_NAME], 'value default'
+        )

mayan/apps/smart_settings/utils.py

@@ -141,12 +141,24 @@ class BaseSetting(object):
         By default will try to get the value from the namespace symbol table,
         then the configuration file, and finally from the environment.
         """
+        # Resolution order
+        # 1 - Environment
+        # 2 - Config
+        # 3 - Global
+        # 4 - Default
         try:
-            return self.namespace.global_symbol_table.get(
-                self.name, self.namespace.get_config_file_setting(name=self.name)
-            )
-        except SettingNamespaceSingleton.SettingNotFound:
             return self.load_environment_value()
+        except SettingNamespaceSingleton.SettingNotFound:
+            try:
+                return self.namespace.get_config_file_setting(name=self.name)
+            except SettingNamespaceSingleton.SettingNotFound:
+                try:
+                    return self.namespace.global_symbol_table[self.name]
+                except KeyError:
+                    if self.has_default:
+                        return self.get_default_value()
+                    else:
+                        raise SettingNamespaceSingleton.SettingNotFound
 
     def load_environment_value(self):
         value = self._get_environment_value()
@@ -161,10 +173,7 @@ class BaseSetting(object):
                     )
                 )
         else:
-            if self.has_default:
-                return self.get_default_value()
-            else:
-                raise SettingNamespaceSingleton.SettingNotFound
+            raise SettingNamespaceSingleton.SettingNotFound
 
 
 class FilesystemBootstrapSetting(BaseSetting):
@@ -190,7 +199,13 @@ class FilesystemBootstrapSetting(BaseSetting):
         because not even the config file setup has completed.
         This setting only supports being set from the environment.
         """
-        return self.load_environment_value()
+        try:
+            return self.load_environment_value()
+        except SettingNamespaceSingleton.SettingNotFound:
+            if self.has_default:
+                return self.get_default_value()
+            else:
+                raise SettingNamespaceSingleton.SettingNotFound
 
 
 class MediaBootstrapSetting(FilesystemBootstrapSetting):