feat(backend): more error messages (#10119)

* Adds error code for transition handler issues #10088

* Adds error codes for mandatory plugins #10094

* add more links

* Add error code  for global overrides

* disable coverage for a case that can not happen

docs/docs/settings/error_codes.md

@@ -50,6 +50,25 @@ This might be caused by an addition or removal of models to the code base or cha
 The settings for SITE_URL and ALLOWED_HOSTS do not match the host used to access the server. This might lead to issues with CSRF protection, CORS and other security features.
 The settings must be adjusted.
 
+#### INVE-E9
+**Transition handler error - Backend**
+An error occurred while discovering or executing a transition handler. This likely indicates a faulty or incompatible plugin.
+This error is raised by a plugin with the `TransitionMixin` and can be debugged by looking into the logs for more information.
+
+#### INVE-E10
+**Plugin cannot be uninstalled or deactivated - Backend**
+A plugin cannot be uninstalled if it is mandatory, a sample or a built-in plugin. Mandatory plugins can not be deactivated.
+
+This is to prevent accidental removal of essential system or compliance functionality. If you want to remove/deactivate a mandatory plugin, you need to remove it from the `INVENTREE_PLUGINS_MANDATORY` [setting](../start/config.md#plugin-options). Sample and built-in plugins can not be uninstalled at all but might be deactivated.
+
+See [Mandatory Plugins](../plugins/index.md#mandatory-plugins) for more information.
+
+#### INVE-E11
+**Plugin cannot override final method - Backend**
+A plugin is not allowed to override a *final method* from the `InvenTreePlugin` class.
+
+This is a security measure to prevent plugins from changing the core functionality of InvenTree. The code of the plugin must be changed to not override functions that are marked as *final*.
+
 ### INVE-W (InvenTree Warning)
 Warnings - These are non-critical errors which should be addressed when possible.
 
@@ -144,5 +163,11 @@ To enable registration, the email settings must be configured correctly. See  [e
 ### INVE-I (InvenTree Information)
 Information — These are not errors but information messages. They might point out potential issues or just provide information.
 
+#### INVE-I1
+**Setting overridden - Backend**
+Overriding a global setting with a different value than the current one.
+
+See [Override global settings](../settings/global.md#override-global-settings) for more information.
+
 ### INVE-M (InvenTree Miscellaneous)
 Miscellaneous — These are information messages that might be used to mark debug information or other messages helpful for the InvenTree team to understand behaviour.

src/backend/InvenTree/InvenTree/settings.py

@@ -1438,7 +1438,9 @@ if SITE_URL:
     GLOBAL_SETTINGS_OVERRIDES['INVENTREE_BASE_URL'] = SITE_URL
 
 if len(GLOBAL_SETTINGS_OVERRIDES) > 0:
-    logger.info('Global settings overrides: %s', str(GLOBAL_SETTINGS_OVERRIDES))
+    logger.info(
+        'INVE-I1: Global settings overrides: %s', str(GLOBAL_SETTINGS_OVERRIDES)
+    )
     for key in GLOBAL_SETTINGS_OVERRIDES:
         # Set the global setting
         logger.debug('- Override value for %s = ********', key)

src/backend/InvenTree/common/apps.py

@@ -56,7 +56,9 @@ class CommonConfig(AppConfig):
 
                 if current_value != value:
                     logger.info(
-                        'Overriding global setting: %s = %s', value, current_value
+                        'INVE-I1: Overriding global setting: %s = %s',
+                        value,
+                        current_value,
                     )
                     set_global_setting(key, value, None, create=True)
 

src/backend/InvenTree/generic/states/transition.py

@@ -107,14 +107,16 @@ class StateTransitionMixin:
 
             if type(handlers) is not list:
                 logger.error(
-                    'Plugin %s returned invalid type for transition handlers',
+                    'INVE-E9: Plugin %s returned invalid type for transition handlers',
                     plugin.slug,
                 )
                 continue
 
             for handler in handlers:
                 if not isinstance(handler, TransitionMethod):
-                    logger.error('Invalid transition handler type: %s', handler)
+                    logger.error(
+                        'INVE-E9: Invalid transition handler type: %s', handler
+                    )
                     continue
 
                 # Call the transition method

src/backend/InvenTree/plugin/base/integration/TransitionMixin.py

@@ -48,14 +48,14 @@ class TransitionMixin:
 
         if not isinstance(handlers, list):
             raise TypeError(
-                'TRANSITION_HANDLERS must be a list of TransitionMethod instances'
+                'INVE-E9: TRANSITION_HANDLERS must be a list of TransitionMethod instances'
             )
 
         handler_methods = []
 
         for handler in handlers:
             if not isinstance(handler, TransitionMethod):
-                logger.error('Invalid transition handler type: %s', handler)
+                logger.error('INVE-E9: Invalid transition handler type: %s', handler)
                 continue
 
             handler_methods.append(handler)

src/backend/InvenTree/plugin/installer.py

@@ -341,17 +341,20 @@ def uninstall_plugin(cfg: plugin.models.PluginConfig, user=None, delete_config=T
             _('Plugin cannot be uninstalled as it is currently active')
         )
 
-    if cfg.is_mandatory():
-        raise ValidationError(_('Plugin cannot be uninstalled as it is mandatory'))
+    if cfg.is_mandatory():  # pragma: no cover
+        # This is only an additional check, as mandatory plugins cannot be deactivated
+        raise ValidationError(
+            'INVE-E10' + _('Plugin cannot be uninstalled as it is mandatory')
+        )
 
     if cfg.is_sample():
         raise ValidationError(
-            _('Plugin cannot be uninstalled as it is a sample plugin')
+            'INVE-E10' + _('Plugin cannot be uninstalled as it is a sample plugin')
         )
 
     if cfg.is_builtin():
         raise ValidationError(
-            _('Plugin cannot be uninstalled as it is a built-in plugin')
+            'INVE-E10' + _('Plugin cannot be uninstalled as it is a built-in plugin')
         )
 
     if not cfg.is_installed():

src/backend/InvenTree/plugin/plugin.py

@@ -332,7 +332,8 @@ class InvenTreePlugin(VersionMixin, MixinBase, MetaBase):
         for name in child_methods:
             if name in final_methods:
                 raise TypeError(
-                    f"Plugin '{cls.__name__}' cannot override final method '{name}' from InvenTreePlugin."
+                    'INVE-E11: '
+                    + f"Plugin '{cls.__name__}' cannot override final method '{name}' from InvenTreePlugin."
                 )
 
         return super().__init_subclass__()

src/backend/InvenTree/plugin/serializers.py

@@ -239,7 +239,9 @@ class PluginActivateSerializer(serializers.Serializer):
         active = validated_data.get('active', True)
 
         if not active and instance.is_mandatory():
-            raise ValidationError(_('Mandatory plugin cannot be deactivated'))
+            raise ValidationError(
+                'INVE-E10: ' + _('Mandatory plugin cannot be deactivated')
+            )
 
         instance.activate(active)
         return instance