Introduce basic checkers

scipost_django/checkers/base.py

+__copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
+__license__ = "AGPL v3"
+
+
+import operator
+
+from django.core.exceptions import ImproperlyConfigured
+from django.db.models import QuerySet
+
+
+class ObjectChecker:
+    model = None
+    queryset = None
+    filter_kwargs = {}
+    max_nr_breakages = 10
+
+    def __init__(self):
+        self.breakages = []
+
+    def get_queryset(self):
+        if self.queryset:
+            queryset = self.queryset
+            if (isinstance(queryset, QuerySet)):
+                queryset = queryset.all()
+        elif self.model:
+            queryset = self.model._default_manager.all()
+        else:
+            raise ImproperlyConfigured(
+                f"{self.__class__.__name__} needs a model or a queryset."
+            )
+        return queryset.filter(**self.filter_kwargs)
+
+    def check(self):
+        self.breakages = []
+        for object in self.get_queryset():
+            self._check_object(object)
+            if len(self.breakages) >= self.max_nr_breakages:
+                return
+
+    def repair_object(self, object):
+        raise NotImplementedError
+
+    def repair_breakages(self):
+        while len(self.breakages) > 0:
+            breakage = self.breakages.pop(0)
+            self.repair_object(breakage["object"])
+
+
+class SingleObjectCheckerMixin:
+    def get_object_info_dict(self, object):
+        return {
+            "checker": self.__class__.__name__,
+            "checker_type": self.checker_type,
+            "object": object,
+            "object_class": object.__class__,
+            "pk": object.id,
+            "url": object.get_absolute_url(),
+        }
+
+
+class ObjectCheckerAttrEqualsValue(SingleObjectCheckerMixin, ObjectChecker):
+    checker_type = "attribute == expected value"
+    attribute = None
+    expected_value = None
+
+    def __init__(self):
+        if not self.attribute:
+            raise ImproperlyConfigured(
+                f"{self.__class__.__name__} needs an `attribute` to check."
+            )
+        elif not self.expected_value:
+            raise ImproperlyConfigured(
+                f"{self.__class__.__name__} needs an `expected_value` to check against."
+            )
+        super().__init__()
+
+    def _check_object(self, object):
+        """
+        Check that object has an attribute with expected value.
+        """
+        value = operator.attrgetter(self.attribute)(object)
+        if value != self.expected_value:
+            info = self.get_object_info_dict(object)
+            info["attribute"] = self.attribute
+            info["expected_value"] = self.expected_value
+            info["value"] = value
+            self.breakages.append(info)
+
+
+class ObjectCheckerAttrEqualsAttr(SingleObjectCheckerMixin, ObjectChecker):
+    checker_type = "attribute1 == attribute2"
+    attribute1 = None
+    attribute2 = None
+
+    def __init__(self):
+        if not self.attribute1 or not self.attribute2:
+            raise ImproperlyConfigured(
+                f"{self.__class__.__name__} needs `attribute1`, `attribute2` to check."
+            )
+        super().__init__()
+
+    def _check_object(self, object):
+        """
+        Check that object has a pair of attributes with correlated value.
+        """
+        value1 = operator.attrgetter(self.attribute1)(object)
+        value2 = operator.attrgetter(self.attribute2)(object)
+        if value2 != value1:
+            info = self.get_object_info_dict(object)
+            info["attribute1"] = self.attribute1
+            info["value1"] = value1
+            info["attribute2"] = self.attribute2
+            info["value2"] = value2
+            self.breakages.append(info)

scipost_django/submissions/checkers.py

+__copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
+__license__ = "AGPL v3"
+
+
+from checkers.base import ObjectCheckerAttrEqualsAttr
+
+from .models import Submission
+
+
+class SubmissionCheckResubmissionThreadAttr(ObjectCheckerAttrEqualsAttr):
+    model = Submission
+    filter_kwargs = {"is_resubmission_of__isnull": False}
+    attribute1 = "thread_hash"
+    attribute2 = "is_resubmission_of.thread_hash"
+
+    def repair_object(self, object):
+        object.thread_hash = object.is_resubmission_of.thread_hash
+        object.save()