Refs #32508 -- Raised Type/ValueError instead of using "assert" in django.db.models.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>

7 files changed, 62 insertions, 49 deletions

diff --git a/django/db/models/base.py b/django/db/models/base.py
index b1202f51c7..f208067aae 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -947,12 +947,12 @@ class Model(metaclass=ModelBase):
                     field.delete_cached_value(self)
 
     def delete(self, using=None, keep_parents=False):
+        if self.pk is None:
+            raise ValueError(
+                "%s object can't be deleted because its %s attribute is set "
+                "to None." % (self._meta.object_name, self._meta.pk.attname)
+            )
         using = using or router.db_for_write(self.__class__, instance=self)
-        assert self.pk is not None, (
-            "%s object can't be deleted because its %s attribute is set to None." %
-            (self._meta.object_name, self._meta.pk.attname)
-        )
-
         collector = Collector(using=using)
         collector.collect([self], keep_parents=keep_parents)
         return collector.delete()
diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index 84c81f9e21..7198d430ce 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -2484,10 +2484,11 @@ class AutoFieldMixin:
         return value
 
     def contribute_to_class(self, cls, name, **kwargs):
-        assert not cls._meta.auto_field, (
-            "Model %s can't have more than one auto-generated field."
-            % cls._meta.label
-        )
+        if cls._meta.auto_field:
+            raise ValueError(
+                "Model %s can't have more than one auto-generated field."
+                % cls._meta.label
+            )
         super().contribute_to_class(cls, name, **kwargs)
         cls._meta.auto_field = self
 
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index a0e8da10fd..8f2a367d65 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -815,13 +815,13 @@ class ForeignKey(ForeignObject):
         try:
             to._meta.model_name
         except AttributeError:
-            assert isinstance(to, str), (
-                "%s(%r) is invalid. First parameter to ForeignKey must be "
-                "either a model, a model name, or the string %r" % (
-                    self.__class__.__name__, to,
-                    RECURSIVE_RELATIONSHIP_CONSTANT,
+            if not isinstance(to, str):
+                raise TypeError(
+                    '%s(%r) is invalid. First parameter to ForeignKey must be '
+                    'either a model, a model name, or the string %r' % (
+                        self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT,
+                    )
                 )
-            )
         else:
             # For backwards compatibility purposes, we need to *try* and set
             # the to_field during FK construction. It won't be guaranteed to
@@ -1169,18 +1169,20 @@ class ManyToManyField(RelatedField):
         try:
             to._meta
         except AttributeError:
-            assert isinstance(to, str), (
-                "%s(%r) is invalid. First parameter to ManyToManyField must be "
-                "either a model, a model name, or the string %r" %
-                (self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT)
-            )
+            if not isinstance(to, str):
+                raise TypeError(
+                    '%s(%r) is invalid. First parameter to ManyToManyField '
+                    'must be either a model, a model name, or the string %r' % (
+                        self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT,
+                    )
+                )
 
         if symmetrical is None:
             symmetrical = (to == RECURSIVE_RELATIONSHIP_CONSTANT)
 
-        if through is not None:
-            assert db_table is None, (
-                "Cannot specify a db_table if an intermediary model is used."
+        if through is not None and db_table is not None:
+            raise ValueError(
+                'Cannot specify a db_table if an intermediary model is used.'
             )
 
         kwargs['rel'] = self.rel_class(
diff --git a/django/db/models/functions/datetime.py b/django/db/models/functions/datetime.py
index 7fc49897b5..20161bef38 100644
--- a/django/db/models/functions/datetime.py
+++ b/django/db/models/functions/datetime.py
@@ -214,9 +214,10 @@ class TruncBase(TimezoneMixin, Transform):
         copy = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
         field = copy.lhs.output_field
         # DateTimeField is a subclass of DateField so this works for both.
-        assert isinstance(field, (DateField, TimeField)), (
-            "%r isn't a DateField, TimeField, or DateTimeField." % field.name
-        )
+        if not isinstance(field, (DateField, TimeField)):
+            raise TypeError(
+                "%r isn't a DateField, TimeField, or DateTimeField." % field.name
+            )
         # If self.output_field was None, then accessing the field will trigger
         # the resolver to assign it to self.lhs.output_field.
         if not isinstance(copy.output_field, (DateField, DateTimeField, TimeField)):
diff --git a/django/db/models/indexes.py b/django/db/models/indexes.py
index cc91c70479..9c393ca2c0 100644
--- a/django/db/models/indexes.py
+++ b/django/db/models/indexes.py
@@ -161,10 +161,11 @@ class Index:
             column_names[0][:7],
             '%s_%s' % (names_digest(*hash_data, length=6), self.suffix),
         )
-        assert len(self.name) <= self.max_name_length, (
-            'Index too long for multiple database support. Is self.suffix '
-            'longer than 3 characters?'
-        )
+        if len(self.name) > self.max_name_length:
+            raise ValueError(
+                'Index too long for multiple database support. Is self.suffix '
+                'longer than 3 characters?'
+            )
         if self.name[0] == '_' or self.name[0].isdigit():
             self.name = 'D%s' % self.name[1:]
 
diff --git a/django/db/models/query.py b/django/db/models/query.py
index 7856cf1a9f..71a52fb754 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -291,10 +291,14 @@ class QuerySet:
                 'QuerySet indices must be integers or slices, not %s.'
                 % type(k).__name__
             )
-        assert ((not isinstance(k, slice) and (k >= 0)) or
-                (isinstance(k, slice) and (k.start is None or k.start >= 0) and
-                 (k.stop is None or k.stop >= 0))), \
-            "Negative indexing is not supported."
+        if (
+            (isinstance(k, int) and k < 0) or
+            (isinstance(k, slice) and (
+                (k.start is not None and k.start < 0) or
+                (k.stop is not None and k.stop < 0)
+            ))
+        ):
+            raise ValueError('Negative indexing is not supported.')
 
         if self._result_cache is not None:
             return self._result_cache[k]
@@ -480,7 +484,8 @@ class QuerySet:
         # PostgreSQL via the RETURNING ID clause. It should be possible for
         # Oracle as well, but the semantics for extracting the primary keys is
         # trickier so it's not done yet.
-        assert batch_size is None or batch_size > 0
+        if batch_size is not None and batch_size <= 0:
+            raise ValueError('Batch size must be a positive integer.')
         # Check that the parents share the same concrete model with the our
         # model to detect the inheritance pattern ConcreteGrandParent ->
         # MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy
@@ -900,10 +905,10 @@ class QuerySet:
         Return a list of date objects representing all available dates for
         the given field_name, scoped to 'kind'.
         """
-        assert kind in ('year', 'month', 'week', 'day'), \
-            "'kind' must be one of 'year', 'month', 'week', or 'day'."
-        assert order in ('ASC', 'DESC'), \
-            "'order' must be either 'ASC' or 'DESC'."
+        if kind not in ('year', 'month', 'week', 'day'):
+            raise ValueError("'kind' must be one of 'year', 'month', 'week', or 'day'.")
+        if order not in ('ASC', 'DESC'):
+            raise ValueError("'order' must be either 'ASC' or 'DESC'.")
         return self.annotate(
             datefield=Trunc(field_name, kind, output_field=DateField()),
             plain_field=F(field_name)
@@ -916,10 +921,13 @@ class QuerySet:
         Return a list of datetime objects representing all available
         datetimes for the given field_name, scoped to 'kind'.
         """
-        assert kind in ('year', 'month', 'week', 'day', 'hour', 'minute', 'second'), \
-            "'kind' must be one of 'year', 'month', 'week', 'day', 'hour', 'minute', or 'second'."
-        assert order in ('ASC', 'DESC'), \
-            "'order' must be either 'ASC' or 'DESC'."
+        if kind not in ('year', 'month', 'week', 'day', 'hour', 'minute', 'second'):
+            raise ValueError(
+                "'kind' must be one of 'year', 'month', 'week', 'day', "
+                "'hour', 'minute', or 'second'."
+            )
+        if order not in ('ASC', 'DESC'):
+            raise ValueError("'order' must be either 'ASC' or 'DESC'.")
         if settings.USE_TZ:
             if tzinfo is None:
                 tzinfo = timezone.get_current_timezone()
diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 2412e6ad4e..b3d92d786c 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -567,14 +567,14 @@ class Query(BaseExpression):
         The 'connector' parameter describes how to connect filters from the
         'rhs' query.
         """
-        assert self.model == rhs.model, \
-            "Cannot combine queries on two different base models."
+        if self.model != rhs.model:
+            raise TypeError('Cannot combine queries on two different base models.')
         if self.is_sliced:
             raise TypeError('Cannot combine queries once a slice has been taken.')
-        assert self.distinct == rhs.distinct, \
-            "Cannot combine a unique query with a non-unique query."
-        assert self.distinct_fields == rhs.distinct_fields, \
-            "Cannot combine queries with different distinct fields."
+        if self.distinct != rhs.distinct:
+            raise TypeError('Cannot combine a unique query with a non-unique query.')
+        if self.distinct_fields != rhs.distinct_fields:
+            raise TypeError('Cannot combine queries with different distinct fields.')
 
         # Work out how to relabel the rhs aliases, if necessary.
         change_map = {}