def from_model(
model, # type: Type[dm.Model]
**field_strategies # type: Union[st.SearchStrategy[Any], InferType]
):
# type: (...) -> st.SearchStrategy[Any]
"""Return a strategy for examples of ``model``.
.. warning::
Hypothesis creates saved models. This will run inside your testing
transaction when using the test runner, but if you use the dev console
this will leave debris in your database.
``model`` must be an subclass of :class:`~django:django.db.models.Model`.
Strategies for fields may be passed as keyword arguments, for example
``is_staff=st.just(False)``.
Hypothesis can often infer a strategy based the field type and validators,
and will attempt to do so for any required fields. No strategy will be
inferred for an :class:`~django:django.db.models.AutoField`, nullable field,
foreign key, or field for which a keyword
argument is passed to ``from_model()``. For example,
a Shop type with a foreign key to Company could be generated with::
shop_strategy = from_model(Shop, company=from_model(Company))
Like for :func:`~hypothesis.strategies.builds`, you can pass
:obj:`~hypothesis.infer` as a keyword argument to infer a strategy for
a field which has a default value instead of using the default.
"""
if not issubclass(model, dm.Model):
raise InvalidArgument("model=%r must be a subtype of Model" % (model,))
fields_by_name = {f.name: f for f in model._meta.concrete_fields}
for name, value in sorted(field_strategies.items()):
if value is infer:
field_strategies[name] = from_field(fields_by_name[name])
for name, field in sorted(fields_by_name.items()):
if (
name not in field_strategies
and not field.auto_created
and field.default is dm.fields.NOT_PROVIDED
):
field_strategies[name] = from_field(field)
for field in field_strategies:
if model._meta.get_field(field).primary_key:
# The primary key is generated as part of the strategy. We
# want to find any existing row with this primary key and
# overwrite its contents.
kwargs = {field: field_strategies.pop(field)}
kwargs["defaults"] = st.fixed_dictionaries(field_strategies) # type: ignore
return _models_impl(st.builds(model.objects.update_or_create, **kwargs))
# The primary key is not generated as part of the strategy, so we
# just match against any row that has the same value for all
# fields.
return _models_impl(st.builds(model.objects.get_or_create, **field_strategies))
def ip4_addr_strings() -> SearchStrategy[str]:
"""A strategy for IPv4 address strings.
This consists of four strings representing integers [0..255],
without zero-padding, joined by dots.
"""
return st.builds("{}.{}.{}.{}".format, *(4 * [st.integers(0, 255)]))
def mac_addr_strings():
# type: () -> SearchStrategy[Text]
"""A strategy for MAC address strings.
This consists of six strings representing integers [0..255],
without zero-padding, joined by dots.
"""
return st.builds("{:02X}:{:02X}:{:02X}:{:02X}:{:02X}:{:02X}".format,
*(6 * [st.integers(0, 255)]))
def urls() -> SearchStrategy[str]:
"""A strategy for :rfc:`3986`, generating http/https URLs."""
def url_encode(s):
return "".join(c if c in URL_SAFE_CHARACTERS else "%%%02X" % ord(c)
for c in s)
schemes = st.sampled_from(["http", "https"])
ports = st.integers(min_value=0, max_value=2**16 - 1).map(":{}".format)
paths = st.lists(st.text(string.printable).map(url_encode)).map("/".join)
return st.builds("{}://{}{}/{}".format, schemes, domains(),
st.just("") | ports, paths)
def from_model(
*model: Type[dm.Model],
**field_strategies: Union[st.SearchStrategy,
InferType]) -> st.SearchStrategy:
"""Return a strategy for examples of ``model``.
.. warning::
Hypothesis creates saved models. This will run inside your testing
transaction when using the test runner, but if you use the dev console
this will leave debris in your database.
``model`` must be an subclass of :class:`~django:django.db.models.Model`.
Strategies for fields may be passed as keyword arguments, for example
``is_staff=st.just(False)``. In order to support models with fields named
"model", this is a positional-only parameter.
Hypothesis can often infer a strategy based the field type and validators,
and will attempt to do so for any required fields. No strategy will be
inferred for an :class:`~django:django.db.models.AutoField`, nullable field,
foreign key, or field for which a keyword
argument is passed to ``from_model()``. For example,
a Shop type with a foreign key to Company could be generated with::
shop_strategy = from_model(Shop, company=from_model(Company))
Like for :func:`~hypothesis.strategies.builds`, you can pass
:obj:`~hypothesis.infer` as a keyword argument to infer a strategy for
a field which has a default value instead of using the default.
"""
if len(model) == 1:
m_type = model[0]
elif len(model) > 1:
raise TypeError("Too many positional arguments")
else:
try:
m_type = field_strategies.pop("model") # type: ignore
except KeyError:
raise TypeError(
"Missing required positional argument `model`") from None
else:
note_deprecation(
"The `model` argument will be positional-only in a future version",
since="2020-03-18",
)
if not issubclass(m_type, dm.Model):
raise InvalidArgument("model=%r must be a subtype of Model" %
(model, ))
fields_by_name = {f.name: f for f in m_type._meta.concrete_fields}
for name, value in sorted(field_strategies.items()):
if value is infer:
field_strategies[name] = from_field(fields_by_name[name])
for name, field in sorted(fields_by_name.items()):
if (name not in field_strategies and not field.auto_created
and field.default is dm.fields.NOT_PROVIDED):
field_strategies[name] = from_field(field)
for field in field_strategies:
if m_type._meta.get_field(field).primary_key:
# The primary key is generated as part of the strategy. We
# want to find any existing row with this primary key and
# overwrite its contents.
kwargs = {field: field_strategies.pop(field)}
kwargs["defaults"] = st.fixed_dictionaries(
field_strategies) # type: ignore
return _models_impl(
st.builds(m_type.objects.update_or_create, **kwargs))
# The primary key is not generated as part of the strategy, so we
# just match against any row that has the same value for all
# fields.
return _models_impl(
st.builds(m_type.objects.get_or_create, **field_strategies))
def from_form(
form: Type[df.Form],
form_kwargs: dict = None,
**field_strategies: Union[st.SearchStrategy, InferType]
) -> st.SearchStrategy[df.Form]:
"""Return a strategy for examples of ``form``.
``form`` must be an subclass of :class:`~django:django.forms.Form`.
Strategies for fields may be passed as keyword arguments, for example
``is_staff=st.just(False)``.
Hypothesis can often infer a strategy based the field type and validators,
and will attempt to do so for any required fields. No strategy will be
inferred for a disabled field or field for which a keyword argument
is passed to ``from_form()``.
This function uses the fields of an unbound ``form`` instance to determine
field strategies, any keyword arguments needed to instantiate the unbound
``form`` instance can be passed into ``from_form()`` as a dict with the
keyword ``form_kwargs``. E.g.::
shop_strategy = from_form(Shop, form_kwargs={"company_id": 5})
Like for :func:`~hypothesis.strategies.builds`, you can pass
:obj:`~hypothesis.infer` as a keyword argument to infer a strategy for
a field which has a default value instead of using the default.
"""
# currently unsupported:
# ComboField
# FilePathField
# FileField
# ImageField
form_kwargs = form_kwargs or {}
if not issubclass(form, df.BaseForm):
raise InvalidArgument("form=%r must be a subtype of Form" % (form, ))
# Forms are a little bit different from models. Model classes have
# all their fields defined, whereas forms may have different fields
# per-instance. So, we ought to instantiate the form and get the
# fields from the instance, thus we need to accept the kwargs for
# instantiation as well as the explicitly defined strategies
unbound_form = form(**form_kwargs)
fields_by_name = {}
for name, field in unbound_form.fields.items():
if isinstance(field, df.MultiValueField):
# PS: So this is a little strange, but MultiValueFields must
# have their form data encoded in a particular way for the
# values to actually be picked up by the widget instances'
# ``value_from_datadict``.
# E.g. if a MultiValueField named 'mv_field' has 3
# sub-fields then the ``value_from_datadict`` will look for
# 'mv_field_0', 'mv_field_1', and 'mv_field_2'. Here I'm
# decomposing the individual sub-fields into the names that
# the form validation process expects
for i, _field in enumerate(field.fields):
fields_by_name["%s_%d" % (name, i)] = _field
else:
fields_by_name[name] = field
for name, value in sorted(field_strategies.items()):
if value is infer:
field_strategies[name] = from_field(fields_by_name[name])
for name, field in sorted(fields_by_name.items()):
if name not in field_strategies and not field.disabled:
field_strategies[name] = from_field(field)
return _forms_impl(
st.builds(
partial(form, **form_kwargs),
data=st.fixed_dictionaries(field_strategies), # type: ignore
))
def models(
model, # type: Type[dm.Model]
**field_strategies # type: Union[st.SearchStrategy[Any], DefaultValueType]
):
# type: (...) -> st.SearchStrategy[Any]
"""Return a strategy for examples of ``model``.
.. warning::
Hypothesis creates saved models. This will run inside your testing
transaction when using the test runner, but if you use the dev console
this will leave debris in your database.
``model`` must be an subclass of :class:`~django:django.db.models.Model`.
Strategies for fields may be passed as keyword arguments, for example
``is_staff=st.just(False)``.
Hypothesis can often infer a strategy based the field type and validators
- for best results, make sure your validators are derived from Django's
and therefore have the known types and attributes.
Passing a keyword argument skips inference for that field; pass a strategy
or pass ``hypothesis.extra.django.models.default_value`` to skip
inference for that field.
Foreign keys are not automatically derived. If they're nullable they will
default to always being null, otherwise you always have to specify them.
For example, examples of a Shop type with a foreign key to Company could
be generated with::
shop_strategy = models(Shop, company=models(Company))
"""
note_deprecation(
"`hypothesis.extra.django.models.models` is deprecated; use `hypothesis.extra.django."
"from_model` instead.",
since="2019-01-10",
)
result = {}
for k, v in field_strategies.items():
if not isinstance(v, DefaultValueType):
result[k] = v
missed = [] # type: List[Text]
for f in model._meta.concrete_fields:
if not (f.name in field_strategies or isinstance(f, dm.AutoField)):
result[f.name] = from_field(f)
if result[f.name].is_empty:
missed.append(f.name)
if missed:
raise InvalidArgument(
u"Missing arguments for mandatory field%s %s for model %s" %
(u"s" if len(missed) > 1 else u"", u", ".join(missed),
model.__name__))
for field in result:
if model._meta.get_field(field).primary_key:
# The primary key is generated as part of the strategy. We
# want to find any existing row with this primary key and
# overwrite its contents.
kwargs = {field: result.pop(field)}
kwargs["defaults"] = st.fixed_dictionaries(result)
return _models_impl(
st.builds(model.objects.update_or_create, **kwargs))
# The primary key is not generated as part of the strategy, so we
# just match against any row that has the same value for all
# fields.
return _models_impl(st.builds(model.objects.get_or_create, **result))
