API Reference#
Comparisons#
- testfixtures.compare(*args, x: ~typing.Any = <unspecified>, y: ~typing.Any = <unspecified>, expected: ~typing.Any = <unspecified>, actual: ~typing.Any = <unspecified>, prefix: ~typing.Optional[str] = None, suffix: ~typing.Optional[str] = None, x_label: ~typing.Optional[str] = None, y_label: ~typing.Optional[str] = None, raises: bool = True, recursive: bool = True, strict: bool = False, ignore_eq: bool = False, comparers: ~typing.Optional[~typing.Dict[type, ~typing.Callable[[~typing.Any, ~typing.Any, ~testfixtures.comparison.CompareContext], ~typing.Optional[str]]]] = None, **options: ~typing.Any) Optional[str] #
Compare two objects, raising an
AssertionError
if they are not the same. TheAssertionError
raised will attempt to provide descriptions of the differences found.The two objects to compare can be passed either positionally or using explicit keyword arguments named
x
andy
, orexpected
andactual
, or a mixture of these.- Parameters:
prefix – If provided, in the event of an
AssertionError
being raised, the prefix supplied will be prepended to the message in theAssertionError
. This may be a callable, in which case it will only be resolved if needed.suffix – If provided, in the event of an
AssertionError
being raised, the suffix supplied will be appended to the message in theAssertionError
. This may be a callable, in which case it will only be resolved if needed.x_label – If provided, in the event of an
AssertionError
being raised, the object passed as the first positional argument, orx
keyword argument, will be labelled with this string in the message in theAssertionError
.y_label – If provided, in the event of an
AssertionError
being raised, the object passed as the second positional argument, ory
keyword argument, will be labelled with this string in the message in theAssertionError
.raises – If
False
, the message that would be raised in theAssertionError
will be returned instead of the exception being raised.recursive – If
True
, when a difference is found in a nested data structure, attempt to highlight the location of the difference.strict – If
True
, objects will only compare equal if they are of the same type as well as being equal.ignore_eq – If
True
, object equality, which relies on__eq__
being correctly implemented, will not be used. Instead, comparers will be looked up and used and, if no suitable comparer is found, objects will be considered equal if their hash is equal.comparers – If supplied, should be a dictionary mapping types to comparer functions for those types. These will be added to the comparer registry for the duration of this call.
Any other keyword parameters supplied will be passed to the functions that end up doing the comparison. See the
API documentation below
for details of these.
- class testfixtures.Comparison(object_or_type, attribute_dict: Optional[Dict[str, Any]] = None, partial: bool = False, **attributes: Any)#
These are used when you need to compare an object’s type, a subset of its attributes or make equality checks with objects that do not natively support comparison.
- Parameters:
object_or_type – The object or class from which to create the
Comparison
.attribute_dict – An optional dictionary containing attributes to place on the
Comparison
.partial – If true, only the specified attributes will be checked and any extra attributes of the object being compared with will be ignored.
attributes – Any other keyword parameters passed will placed as attributes on the
Comparison
.
- class testfixtures.MappingComparison(*expected_mapping, **expected_items)#
An object that can be used in comparisons of expected and actual mappings.
- Parameters:
expected_mapping – The mapping that should be matched expressed as either a sequence of
(key, value)
tuples or a mapping.expected_items – The items that should be matched.
ordered – If
True
, then the keys in the mapping are expected to be in the order specified. Defaults toFalse
.partial – If
True
, then any keys not expected will be ignored. Defaults toFalse
.recursive – If a difference is found, recursively compare the value where the difference was found to highlight exactly what was different. Defaults to
False
.
- class testfixtures.Permutation(*expected)#
A shortcut for
SequenceComparison
that checks if the set of items in the sequence is as expected, but without checking ordering.
- class testfixtures.RoundComparison(value: float, precision: int)#
An object that can be used in comparisons of expected and actual numerics to a specified precision.
- Parameters:
value – numeric to be compared.
precision – Number of decimal places to round to in order to perform the comparison.
- class testfixtures.RangeComparison(lower_bound, upper_bound)#
An object that can be used in comparisons of orderable types to check that a value specified within the given range.
- Parameters:
lower_bound – the inclusive lower bound for the acceptable range.
upper_bound – the inclusive upper bound for the acceptable range.
- class testfixtures.SequenceComparison(*expected, ordered: bool = True, partial: bool = False, recursive: bool = False)#
An object that can be used in comparisons of expected and actual sequences.
- Parameters:
expected – The items expected to be in the sequence.
ordered – If
True
, then the items are expected to be in the order specified. IfFalse
, they may be in any order. Defaults toTrue
.partial – If
True
, then any keys not expected will be ignored. Defaults toFalse
.recursive – If a difference is found, recursively compare the item where the difference was found to highlight exactly what was different. Defaults to
False
.
- class testfixtures.Subset(*expected)#
A shortcut for
SequenceComparison
that checks if the specified items are present in the sequence.
- class testfixtures.StringComparison(regex_source: str, flags: Optional[int] = None, **flag_names: str)#
An object that can be used in comparisons of expected and actual strings where the string expected matches a pattern rather than a specific concrete string.
- Parameters:
regex_source – A string containing the source for a regular expression that will be used whenever this
StringComparison
is compared with anystr
instance.flags – Flags passed to
re.compile()
.flag_names – See the examples.
testfixtures.comparison#
- testfixtures.comparison.register(type_: type, comparer: Callable[[Any, Any, CompareContext], Optional[str]])#
Register the supplied comparer for the specified type. This registration is global and will be in effect from the point this function is called until the end of the current process.
- testfixtures.comparison.compare_simple(x, y, context: CompareContext)#
Returns a very simple textual difference between the two supplied objects.
- testfixtures.comparison.compare_object(x, y, context: CompareContext, ignore_attributes: Iterable[str] = ()) Optional[str] #
Compare the two supplied objects based on their type and attributes.
- Parameters:
ignore_attributes –
Either a sequence of strings containing attribute names to be ignored when comparing or a mapping of type to sequence of strings containing attribute names to be ignored when comparing that type.
This may be specified as either a parameter to this function or in the
context
. If specified in both, they will both apply with precedence given to whatever is specified is specified as a parameter. If specified as a parameter to this function, it may only be a list of strings.
- testfixtures.comparison.compare_exception(x: Exception, y: Exception, context: CompareContext) Optional[str] #
Compare the two supplied exceptions based on their message, type and attributes.
- testfixtures.comparison.compare_with_type(x, y, context: CompareContext) str #
Return a textual description of the difference between two objects including information about their types.
- testfixtures.comparison.compare_sequence(x: Sequence, y: Sequence, context: CompareContext, prefix: bool = True) Optional[str] #
Returns a textual description of the differences between the two supplied sequences.
- testfixtures.comparison.compare_generator(x: Generator, y: Generator, context: CompareContext) Optional[str] #
Returns a textual description of the differences between the two supplied generators.
This is done by first unwinding each of the generators supplied into tuples and then passing those tuples to
compare_sequence()
.
- testfixtures.comparison.compare_tuple(x: tuple, y: tuple, context: CompareContext) Optional[str] #
Returns a textual difference between two tuples or
collections.namedtuple()
instances.The presence of a
_fields
attribute on a tuple is used to decide whether or not it is anamedtuple()
.
- testfixtures.comparison.compare_dict(x: dict, y: dict, context: CompareContext) Optional[str] #
Returns a textual description of the differences between the two supplied dictionaries.
- testfixtures.comparison.compare_set(x: set, y: set, context: CompareContext) Optional[str] #
Returns a textual description of the differences between the two supplied sets.
- testfixtures.comparison.compare_text(x: str, y: str, context: CompareContext)#
Returns an informative string describing the differences between the two supplied strings. The way in which this comparison is performed can be controlled using the following parameters:
- Parameters:
blanklines – If False, then when comparing multi-line strings, any blank lines in either argument will be ignored.
trailing_whitespace – If False, then when comparing multi-line strings, trailing whilespace on lines will be ignored.
show_whitespace – If True, then whitespace characters in multi-line strings will be replaced with their representations.
- class testfixtures.comparison.CompareContext(x_label: Optional[str], y_label: Optional[str], recursive: bool = True, strict: bool = False, ignore_eq: bool = False, comparers: Optional[Dict[type, Callable[[Any, Any, CompareContext], Optional[str]]]] = None, options: Optional[Dict[str, Any]] = None)#
Stores the context of the current comparison in process during a call to
testfixtures.compare()
.
Capturing#
- class testfixtures.LogCapture(names: Optional[Union[str, Tuple[str]]] = None, install: bool = True, level: int = 1, propagate: Optional[bool] = None, attributes: Union[Sequence[str], Callable[[LogRecord], Any]] = ('name', 'levelname', 'getMessage'), recursive_check: bool = False, ensure_checks_above: Optional[int] = None)#
These are used to capture entries logged to the Python logging framework and make assertions about what was logged.
- Parameters:
names – A string (or tuple of strings) containing the dotted name(s) of loggers to capture. By default, the root logger is captured.
install – If True, the
LogCapture
will be installed as part of its instantiation.propagate – If specified, any captured loggers will have their propagate attribute set to the supplied value. This can be used to prevent propagation from a child logger to a parent logger that has configured handlers.
attributes –
The sequence of attribute names to return for each record or a callable that extracts a row from a record.
If a sequence of attribute names, those attributes will be taken from the
LogRecord
. If an attribute is callable, the value used will be the result of calling it. If an attribute is missing,None
will be used in its place.If a callable, it will be called with the
LogRecord
and the value returned will be used as the row.recursive_check – If
True
, log messages will be compared recursively byLogCapture.check()
.ensure_checks_above – The log level above which checks must be made for logged events. See
ensure_checked()
.
- actual() List #
The sequence of actual records logged, having had their attributes extracted as specified by the
attributes
parameter to theLogCapture
constructor.This can be useful for making more complex assertions about logged records. The actual records logged can also be inspected by using the
records
attribute.
- check(*expected)#
This will compare the captured entries with the expected entries provided and raise an
AssertionError
if they do not match.- Parameters:
expected – A sequence of entries of the structure specified by the
attributes
passed to the constructor.
- check_present(*expected, order_matters: bool = True)#
This will check if the captured entries contain all of the expected entries provided and raise an
AssertionError
if not. This will ignore entries that have been captured but that do not match those inexpected
.- Parameters:
expected – A sequence of entries of the structure specified by the
attributes
passed to the constructor.order_matters – A keyword-only parameter that controls whether the order of the captured entries is required to match those of the expected entries. Defaults to
True
.
- clear()#
Clear any entries that have been captured.
- ensure_checked(level: Optional[int] = None)#
Ensure every entry logged above the specified level has been checked. Raises an
AssertionError
if this is not the case.- Parameters:
level – the logging level, defaults to
ensure_checks_above
.
- ensure_checks_above: Optional[int]#
The log level above which checks must be made for logged events.
- install()#
Install this
LogCapture
into the Python logging framework for the named loggers.This will remove any existing handlers for those loggers and drop their level to that specified on this
LogCapture
in order to capture all logging.
- mark_all_checked()#
Mark all captured events as checked. This should be called if you have made assertions about logging other than through
LogCapture
methods.
- records: List[LogRecord]#
The records captured by this
LogCapture
.
- uninstall()#
Un-install this
LogCapture
from the Python logging framework for the named loggers.This will re-instate any existing handlers for those loggers that were removed during installation and restore their level that prior to installation.
- classmethod uninstall_all()#
This will uninstall all existing
LogCapture
objects.
- testfixtures.log_capture(*names: str, **kw)#
A decorator for making a
LogCapture
installed and available for the duration of a test function.- Parameters:
names – An optional sequence of names specifying the loggers to be captured. If not specified, the root logger will be captured.
Keyword parameters other than
install
may also be supplied and will be passed on to theLogCapture
constructor.
- class testfixtures.OutputCapture(separate: bool = False, fd: bool = False, strip_whitespace: bool = True)#
A context manager for capturing output to the
sys.stdout
andsys.stderr
streams.- Parameters:
separate – If
True
,stdout
andstderr
will be captured separately and their expected values must be passed tocompare()
.fd – If
True
, the underlying file descriptors will be captured, rather than just the attributes onsys
. This allows you to capture things like subprocesses that write directly to the file descriptors, but is more invasive, so only use it when you need it.strip_whitespace – When
True
, which is the default, leading and training whitespace is trimmed from both the expected and actual values when comparing.
Note
If
separate
is passed asTrue
,OutputCapture.captured
will be an empty string.- compare(expected: str = '', stdout: str = '', stderr: str = '')#
Compare the captured output to that expected. If the output is not the same, an
AssertionError
will be raised.- Parameters:
expected – A string containing the expected combined output of
stdout
andstderr
.stdout – A string containing the expected output to
stdout
.stderr – A string containing the expected output to
stderr
.
- disable()#
Disable the output capture if it is enabled.
- enable()#
Enable the output capture if it is disabled.
Mocking#
- class testfixtures.Replace(target: Any, replacement: R, strict: bool = True, container: Optional[Any] = None, accessor: Optional[Callable[[Any, str], Any]] = None, name: Optional[str] = None)#
A context manager that uses a
Replacer
to replace a single target.- Parameters:
target –
This must be one of the following:
A string containing the dotted-path to the object to be replaced, in which case it will be resolved the the object to be replaced.
This path may specify a module in a package, an attribute of a module, or any attribute of something contained within a module.
The container of the object to be replaced, in which case
name
must be specified.The object to be replaced, in which case
container
must be specified.name
must also be specified if it cannot be obtained from the__name__
attribute of the object to be replaced.
replacement – The object to use as a replacement.
strict – When True, an exception will be raised if an attempt is made to replace an object that does not exist or if the object that is obtained using the
accessor
to access thename
from thecontainer
is not identical to thetarget
.container – The container of the object from which
target
can be accessed using eithergetattr()
orgetitem()
.accessor – Either
getattr()
orgetitem()
. If not supplied, this will be inferred preferringgetitem()
overgetattr()
.name – The name used to access the
target
from thecontainer
using theaccessor
. If required but not specified, the__name__
attribute of thetarget
will be used.
- testfixtures.replace_in_environ(name: str, replacement: Any)#
This context manager provides a quick way to use
Replacer.in_environ()
.
- testfixtures.replace_on_class(attribute: Callable, replacement: Any, name: str = None)#
This context manager provides a quick way to use
Replacer.on_class()
.
- testfixtures.replace_in_module(target: Any, replacement: Any, module: module = None)#
This context manager provides a quick way to use
Replacer.in_module()
.
- class testfixtures.Replacer#
These are used to manage the mocking out of objects so that units of code can be tested without having to rely on their normal dependencies.
- __call__(target: Any, replacement: R, strict: bool = True, container: Optional[Any] = None, accessor: Optional[Callable[[Any, str], Any]] = None, name: Optional[str] = None) R #
Replace the specified target with the supplied replacement.
- Parameters:
target –
This must be one of the following:
A string containing the dotted-path to the object to be replaced, in which case it will be resolved the the object to be replaced.
This path may specify a module in a package, an attribute of a module, or any attribute of something contained within a module.
The container of the object to be replaced, in which case
name
must be specified.The object to be replaced, in which case
container
must be specified.name
must also be specified if it cannot be obtained from the__name__
attribute of the object to be replaced.
replacement – The object to use as a replacement.
strict – When True, an exception will be raised if an attempt is made to replace an object that does not exist or if the object that is obtained using the
accessor
to access thename
from thecontainer
is not identical to thetarget
.container – The container of the object from which
target
can be accessed using eithergetattr()
orgetitem()
.accessor – Either
getattr()
orgetitem()
. If not supplied, this will be inferred preferringgetitem()
overgetattr()
.name – The name used to access the
target
from thecontainer
using theaccessor
. If required but not specified, the__name__
attribute of thetarget
will be used.
- in_environ(name: str, replacement: Any) None #
This method provides a convenient way of ensuring an environment variable in
os.environ
is set to a particular value.If you wish to ensure that an environment variable is not present, then use
not_there
as thereplacement
.
- in_module(target: Any, replacement: Any, module: Optional[module] = None) None #
This method provides a convenient way to replace targets that are module globals, particularly functions or other objects with a
__name__
attribute.If an object has been imported into a module other than the one where it has been defined, then
module
should be used to specify the module where you would like the replacement to occur.
- on_class(attribute: Callable, replacement: Any, name: Optional[str] = None) None #
This method provides a convenient way to replace methods, static methods and class methods on their classes.
If the attribute being replaced has a
__name__
that differs from the attribute name on the class, such as that returned by poorly implemented decorators, thenname
must be used to provide the correct name.
- replace(target: Any, replacement: Any, strict: bool = True, container: Optional[Any] = None, accessor: Optional[Callable[[Any, str], Any]] = None, name: Optional[str] = None) None #
Replace the specified target with the supplied replacement.
- Parameters:
target –
This must be one of the following:
A string containing the dotted-path to the object to be replaced, in which case it will be resolved the the object to be replaced.
This path may specify a module in a package, an attribute of a module, or any attribute of something contained within a module.
The container of the object to be replaced, in which case
name
must be specified.The object to be replaced, in which case
container
must be specified.name
must also be specified if it cannot be obtained from the__name__
attribute of the object to be replaced.
replacement – The object to use as a replacement.
strict – When True, an exception will be raised if an attempt is made to replace an object that does not exist or if the object that is obtained using the
accessor
to access thename
from thecontainer
is not identical to thetarget
.container – The container of the object from which
target
can be accessed using eithergetattr()
orgetitem()
.accessor – Either
getattr()
orgetitem()
. If not supplied, this will be inferred preferringgetitem()
overgetattr()
.name – The name used to access the
target
from thecontainer
using theaccessor
. If required but not specified, the__name__
attribute of thetarget
will be used.
- testfixtures.replace(target: Any, replacement: Any, strict: bool = True, container: Optional[Any] = None, accessor: Optional[Callable[[Any, str], Any]] = None, name: Optional[str] = None) Callable[[Callable], Callable] #
A decorator to replace a target object for the duration of a test function.
- Parameters:
target –
This must be one of the following:
A string containing the dotted-path to the object to be replaced, in which case it will be resolved the the object to be replaced.
This path may specify a module in a package, an attribute of a module, or any attribute of something contained within a module.
The container of the object to be replaced, in which case
name
must be specified.The object to be replaced, in which case
container
must be specified.name
must also be specified if it cannot be obtained from the__name__
attribute of the object to be replaced.
replacement – The object to use as a replacement.
strict – When True, an exception will be raised if an attempt is made to replace an object that does not exist or if the object that is obtained using the
accessor
to access thename
from thecontainer
is not identical to thetarget
.container – The container of the object from which
target
can be accessed using eithergetattr()
orgetitem()
.accessor – Either
getattr()
orgetitem()
. If not supplied, this will be inferred preferringgetitem()
overgetattr()
.name – The name used to access the
target
from thecontainer
using theaccessor
. If required but not specified, the__name__
attribute of thetarget
will be used.
- testfixtures.mock_date(delta: float = None, delta_type: str = None, date_type: Type[date] = date, strict: bool = False) Type[MockDate] #
- testfixtures.mock_date(year: int, month: int, day: int, delta: float = None, delta_type: str = 'days', strict: bool = False) Type[MockDate]
- testfixtures.mock_date(default: date, delta: float = None, delta_type: str = 'days', strict: bool = False) Type[MockDate]
- testfixtures.mock_date(default: None, delta: float = None, delta_type: str = 'days', strict: bool = False) Type[MockDate]
A function that returns a mock object that can be used in place of the
datetime.date
class but where the return value oftoday()
can be controlled.If a single positional argument of
None
is passed, then the queue of dates to be returned will be empty and you will need to callset()
oradd()
before callingtoday()
.If an instance of
date
is passed as a single positional argument, that will be used as the first date returned bytoday()
- Parameters:
year – An optional year used to create the first date returned by
today()
.month – An optional month used to create the first date returned by
today()
.day – An optional day used to create the first date returned by
today()
.delta – The size of the delta to use between values returned from
today()
. If not specified, it will increase by 1 with each call totoday()
.delta_type – The type of the delta to use between values returned from
today()
. This can be any keyword parameter accepted by thetimedelta
constructor.strict – If
True
, calling the mock class and any of its methods will result in an instance of the mock being returned. IfFalse
, the default, an instance ofdate
will be returned instead.
The mock returned will behave exactly as the
datetime.date
class as well as being a subclass ofMockDate
.
- class testfixtures.datetime.MockDate(*args, **kw)#
- classmethod add(year: int, month: int, day: int) None #
- classmethod add(instance: date) None
This will add the
datetime.date
created from the supplied parameters to the queue of dates to be returned bytoday()
. An instance ofdate
may also be passed as a single positional argument.
- classmethod set(year: int, month: int, day: int) None #
- classmethod set(instance: date) None
This will set the
datetime.date
created from the supplied parameters as the next date to be returned bytoday()
, regardless of any dates in the queue. An instance ofdate
may also be passed as a single positional argument.
- classmethod tick(days: float = ..., weeks: float = ...) None #
- classmethod tick(delta: timedelta) None
This method should be called either with a
timedelta
as a positional argument, or with keyword parameters that will be used to construct atimedelta
.The
timedelta
will be used to advance the next date to be returned bytoday()
.
- testfixtures.mock_datetime(tzinfo: tzinfo = None, delta: float = None, delta_type: str = 'seconds', date_type: Type[date] = date, strict: bool = False) Type[MockDateTime] #
- testfixtures.mock_datetime(year: int, month: int, day: int, hour: int = ..., minute: int = ..., second: int = ..., microsecond: int = ..., tzinfo: tzinfo = None, delta: float = None, delta_type: str = 'seconds', date_type: Type[date] = date, strict: bool = False) Type[MockDateTime]
- testfixtures.mock_datetime(default: datetime, tzinfo: tzinfo = None, delta: float = None, delta_type: str = 'seconds', date_type: Type[date] = date, strict: bool = False) Type[MockDateTime]
- testfixtures.mock_datetime(default: None, tzinfo: tzinfo = None, delta: float = None, delta_type: str = 'seconds', date_type: Type[date] = date, strict: bool = False) Type[MockDateTime]
A function that returns a mock object that can be used in place of the
datetime.datetime
class but where the return value ofnow()
can be controlled.If a single positional argument of
None
is passed, then the queue of datetimes to be returned will be empty and you will need to callset()
oradd()
before callingnow()
orutcnow()
.If an instance of
datetime
is passed as a single positional argument, that will be used as the first date returned bynow()
- Parameters:
year – An optional year used to create the first datetime returned by
now()
.month – An optional month used to create the first datetime returned by
now()
.day – An optional day used to create the first datetime returned by
now()
.hour – An optional hour used to create the first datetime returned by
now()
.minute – An optional minute used to create the first datetime returned by
now()
.second – An optional second used to create the first datetime returned by
now()
.microsecond – An optional microsecond used to create the first datetime returned by
now()
.tzinfo – An optional
datetime.tzinfo
, see Timezones.delta – The size of the delta to use between values returned from mocked class methods. If not specified, it will increase by 1 with each call to
now()
.delta_type – The type of the delta to use between values returned from mocked class methods. This can be any keyword parameter accepted by the
timedelta
constructor.date_type – The type to use for the return value of the mocked class methods. This can help with gotchas that occur when type checking is performed on values returned by the
date()
method.strict – If
True
, calling the mock class and any of its methods will result in an instance of the mock being returned. IfFalse
, the default, an instance ofdatetime
will be returned instead.
The mock returned will behave exactly as the
datetime.datetime
class as well as being a subclass ofMockDateTime
.
- class testfixtures.datetime.MockDateTime(*args, **kw)#
- classmethod add(year: int, month: int, day: int, hour: int = ..., minute: int = ..., second: int = ..., microsecond: int = ..., tzinfo: tzinfo = ...) None #
- classmethod add(instance: datetime) None
This will add the
datetime.datetime
created from the supplied parameters to the queue of datetimes to be returned bynow()
orutcnow()
. An instance ofdatetime
may also be passed as a single positional argument.
- classmethod set(year: int, month: int, day: int, hour: int = ..., minute: int = ..., second: int = ..., microsecond: int = ..., tzinfo: tzinfo = ...) None #
- classmethod set(instance: datetime) None
This will set the
datetime.datetime
created from the supplied parameters as the next datetime to be returned bynow()
orutcnow()
, clearing out any datetimes in the queue. An instance ofdatetime
may also be passed as a single positional argument.
- classmethod tick(days: float = ..., seconds: float = ..., microseconds: float = ..., milliseconds: float = ..., minutes: float = ..., hours: float = ..., weeks: float = ...) None #
- classmethod tick(delta: timedelta) None
This method should be called either with a
timedelta
as a positional argument, or with keyword parameters that will be used to construct atimedelta
.The
timedelta
will be used to advance the next datetime to be returned bynow()
orutcnow()
.
- classmethod now(tz: Optional[tzinfo] = None) datetime #
- Parameters:
tz – An optional timezone to apply to the returned time. If supplied, it must be an instance of a
tzinfo
subclass.
This will return the next supplied or calculated datetime from the internal queue, rather than the actual current datetime.
If tz is supplied, see Timezones.
- testfixtures.mock_time(delta: float = None, delta_type: str = 'seconds') Type[MockTime] #
- testfixtures.mock_time(year: int, month: int, day: int, hour: int = ..., minute: int = ..., second: int = ..., microsecond: int = ..., delta: float = None, delta_type: str = 'seconds') Type[MockTime]
- testfixtures.mock_time(default: datetime, delta: float = None, delta_type: str = 'seconds') Type[MockTime]
- testfixtures.mock_time(default: None, delta: float = None, delta_type: str = 'seconds') Type[MockTime]
A function that returns a
mock object
that can be used in place of thetime.time()
function but where the return value can be controlled.If a single positional argument of
None
is passed, then the queue of times to be returned will be empty and you will need to callset()
oradd()
before calling the mock.If an instance of
datetime
is passed as a single positional argument, that will be used to create the first time returned.- Parameters:
year – An optional year used to create the first time returned.
month – An optional month used to create the first time.
day – An optional day used to create the first time.
hour – An optional hour used to create the first time.
minute – An optional minute used to create the first time.
second – An optional second used to create the first time.
microsecond – An optional microsecond used to create the first time.
delta – The size of the delta to use between values returned. If not specified, it will increase by 1 with each call to the mock.
delta_type – The type of the delta to use between values returned. This can be any keyword parameter accepted by the
timedelta
constructor.
The
add()
,set()
andtick()
methods on the mock can be used to control the return values.
- class testfixtures.datetime.MockTime(*args, **kw)#
- classmethod add(year: int, month: int, day: int, hour: int = ..., minute: int = ..., second: int = ..., microsecond: int = ...) None #
- classmethod add(instance: datetime) None
This will add the time specified by the supplied parameters to the queue of times to be returned by calls to the mock. The parameters are the same as the
datetime.datetime
constructor. An instance ofdatetime
may also be passed as a single positional argument.
- classmethod set(year: int, month: int, day: int, hour: int = ..., minute: int = ..., second: int = ..., microsecond: int = ...) None #
- classmethod set(instance: datetime) None
This will set the time specified by the supplied parameters as the next time to be returned by a call to the mock, regardless of any times in the queue. The parameters are the same as the
datetime.datetime
constructor. An instance ofdatetime
may also be passed as a single positional argument.
- classmethod tick(days: float = ..., seconds: float = ..., microseconds: float = ..., milliseconds: float = ..., minutes: float = ..., hours: float = ..., weeks: float = ...) None #
- classmethod tick(delta: timedelta) None
This method should be called either with a
timedelta
as a positional argument, or with keyword parameters that will be used to construct atimedelta
.The
timedelta
will be used to advance the next time to be returned by a call to the mock.
- static __new__(cls, *args, **kw) float #
Return a
float
representing the mocked current time as would normally be returned bytime.time()
.
testfixtures.mock#
A facade for either unittest.mock
or its rolling backport, if it is
installed, with a preference for the latter as it may well have newer functionality
and bugfixes.
The facade also contains any bugfixes that are critical to the operation of functionality provided by testfixtures.
testfixtures.popen#
- class testfixtures.popen.MockPopen#
A specialised mock for testing use of
subprocess.Popen
. An instance of this class can be used in place of thesubprocess.Popen
and is often inserted where it’s needed usingunittest.mock.patch()
or aReplacer
.- all_calls: List[_Call]#
All calls made using this mock and the objects it returns, represented using
call()
instances.
- set_command(command: str, stdout: bytes = b'', stderr: bytes = b'', returncode: int = 0, pid: int = 1234, poll_count: int = 3, behaviour: Optional[Union[PopenBehaviour, Callable]] = None)#
Set the behaviour of this mock when it is used to simulate the specified command.
- Parameters:
command – A
str
representing the command to be simulated.stdout –
bytes
representing the simulated content written by the process to the stdout pipe.stderr –
bytes
representing the simulated content written by the process to the stderr pipe.returncode – An integer representing the return code of the simulated process.
pid – An integer representing the process identifier of the simulated process. This is useful if you have code the prints out the pids of running processes.
poll_count – Specifies the number of times
poll()
can be called beforereturncode
is set and returned bypoll()
.
If supplied,
behaviour
must be either aPopenBehaviour
instance or a callable that takes thecommand
string representing the command to be simulated and thestdin
supplied when instantiating thesubprocess.Popen
with that command and should return aPopenBehaviour
instance.
- set_default(stdout=b'', stderr=b'', returncode=0, pid=1234, poll_count=3, behaviour=None)#
Set the behaviour of this mock when it is used to simulate commands that have no explicit behavior specified using
set_command()
.- Parameters:
stdout –
bytes
representing the simulated content written by the process to the stdout pipe.stderr –
bytes
representing the simulated content written by the process to the stderr pipe.returncode – An integer representing the return code of the simulated process.
pid – An integer representing the process identifier of the simulated process. This is useful if you have code the prints out the pids of running processes.
poll_count – Specifies the number of times
poll()
can be called beforereturncode
is set and returned bypoll()
.
If supplied,
behaviour
must be either aPopenBehaviour
instance or a callable that takes thecommand
string representing the command to be simulated and thestdin
supplied when instantiating thesubprocess.Popen
with that command and should return aPopenBehaviour
instance.
- class testfixtures.popen.MockPopenInstance(mock_class, root_call, args, bufsize=0, executable=None, stdin=None, stdout=None, stderr=None, preexec_fn=None, close_fds=False, shell=False, cwd=None, env=None, universal_newlines=False, startupinfo=None, creationflags=0, restore_signals=True, start_new_session=False, pass_fds=(), encoding=None, errors=None, text=None)#
A mock process as returned by
MockPopen
.- communicate(input: Union[str, bytes] = None, timeout: float = None) Tuple[Union[str, bytes], Union[str, bytes]] #
Simulate calls to
subprocess.Popen.communicate()
- kill() None #
Simulate calls to
subprocess.Popen.kill()
- poll() Optional[int] #
Simulate calls to
subprocess.Popen.poll()
- root_call: _Call#
A
unittest.mock.call()
representing the call made to instantiate this mock process.
- send_signal(signal: int) None #
Simulate calls to
subprocess.Popen.send_signal()
- stderr: TemporaryFile = None#
A file representing error output from this process.
- stdin: Mock = None#
A
Mock
representing the pipe into this process. This is only set ifstdin=PIPE
is passed the constructor. The mock records writes and closes inMockPopen.all_calls
.
- stdout: TemporaryFile = None#
A file representing standard output from this process.
- terminate() None #
Simulate calls to
subprocess.Popen.terminate()
- wait(timeout: float = None) int #
Simulate calls to
subprocess.Popen.wait()
Assertions#
- class testfixtures.ShouldRaise(exception: Optional[Union[Exception, Type[Exception]]] = None, unless: bool = False)#
This context manager is used to assert that an exception is raised within the context it is managing.
- Parameters:
exception –
This can be one of the following:
None, indicating that an exception must be raised, but the type is unimportant.
An exception class, indicating that the type of the exception is important but not the parameters it is created with.
An exception instance, indicating that an exception exactly matching the one supplied should be raised.
unless – Can be passed a boolean that, when
True
indicates that no exception is expected. This is useful when checking that exceptions are only raised on certain versions of Python.
- raised = None#
The exception captured by the context manager. Can be used to inspect specific attributes of the exception.
- class testfixtures.should_raise(exception: Optional[Union[Exception, Type[Exception]]] = None, unless: Optional[bool] = None)#
A decorator to assert that the decorated function will raised an exception. An exception class or exception instance may be passed to check more specifically exactly what exception will be raised.
- Parameters:
exception –
This can be one of the following:
None, indicating that an exception must be raised, but the type is unimportant.
An exception class, indicating that the type of the exception is important but not the parameters it is created with.
An exception instance, indicating that an exception exactly matching the one supplied should be raised.
unless – Can be passed a boolean that, when
True
indicates that no exception is expected. This is useful when checking that exceptions are only raised on certain versions of Python.
- testfixtures.ShouldAssert(expected_text: str)#
A context manager to check that an
AssertionError
is raised and its text is as expected.
- class testfixtures.ShouldWarn(*expected: Union[Warning, Type[Warning]], **filters)#
This context manager is used to assert that warnings are issued within the context it is managing.
- Parameters:
expected –
This should be a sequence made up of one or more elements, each of one of the following types:
A warning class, indicating that the type of the warnings is important but not the parameters it is created with.
A warning instance, indicating that a warning exactly matching the one supplied should have been issued.
If no expected warnings are passed, you will need to inspect the contents of the list returned by the context manager.
filters – If passed, these are used to create a filter such that only warnings you are interested in will be considered by this
ShouldWarn
instance. The names and meanings are the same as the parameters forwarnings.filterwarnings()
.
- class testfixtures.ShouldNotWarn#
This context manager is used to assert that no warnings are issued within the context it is managing.
Resources#
- class testfixtures.TempDirectory(path: Union[str, Path, py.path.local] = None, *, ignore: Sequence[str] = (), create: bool = None, encoding: str = None)#
A class representing a temporary directory on disk.
- Parameters:
ignore – A sequence of strings containing regular expression patterns that match filenames that should be ignored by the
TempDirectory
listing and checking methods.create – If True, the temporary directory will be created as part of class instantiation.
path – If passed, this should be a string containing an absolute path to use as the temporary directory. When passed,
TempDirectory
will not create a new directory to use.encoding – A default encoding to use for
read()
andwrite()
operations when theencoding
parameter is not passed to those methods.
- as_local(path: Union[str, Tuple[str]] = None) py.path.local #
Return the
py.path.local
that corresponds to the path relative to the temporary directory that is passed in.- Parameters:
path –
The path to the file to create, which can be:
A tuple of strings.
A forward-slash separated string.
- as_path(path: Optional[Union[str, Tuple[str]]] = None) Path #
Return the
Path
that corresponds to the path relative to the temporary directory that is passed in.- Parameters:
path –
The path to the file to create, which can be:
A tuple of strings.
A forward-slash separated string.
- as_string(path: Optional[Union[str, Sequence[str]]] = None) str #
Return the full path on disk that corresponds to the path relative to the temporary directory that is passed in.
- Parameters:
path –
The path to the file to create, which can be:
A tuple of strings.
A forward-slash separated string.
- Returns:
A string containing the absolute path.
- cleanup() None #
Delete the temporary directory and anything in it. This
TempDirectory
cannot be used again unlesscreate()
is called.
- classmethod cleanup_all() None #
Delete all temporary directories associated with all
TempDirectory
objects.
- compare(expected: Sequence[str], path: Optional[Union[str, Tuple[str]]] = None, files_only: bool = False, recursive: bool = True, followlinks: bool = False)#
Compare the expected contents with the actual contents of the temporary directory. An
AssertionError
will be raised if they are not the same.- Parameters:
expected – A sequence of strings containing the paths expected in the directory. These paths should be forward-slash separated and relative to the root of the temporary directory.
path –
The path to use as the root for the comparison, relative to the root of the temporary directory. This can either be:
A tuple of strings, making up the relative path.
A forward-slash separated string.
If it is not provided, the root of the temporary directory will be used.
files_only – If specified, directories will be excluded from the list of actual paths used in the comparison.
recursive – If
False
, only the direct contents of the directory specified bypath
will be included in the actual contents used for comparison.followlinks – If
True
, symlinks and hard links will be followed when recursively building up the actual list of directory contents.
- create() TempDirectory #
Create a temporary directory for this instance to use if one has not already been created.
- getpath(path: Optional[Union[str, Sequence[str]]] = None) str #
Deprecated since version 7.
Use
as_string()
instead.
- listdir(path: Optional[Union[str, Tuple[str]]] = None, recursive: bool = False)#
Print the contents of the specified directory.
- Parameters:
path –
The path to list, which can be:
None, indicating the root of the temporary directory should be listed.
A tuple of strings, indicating that the elements of the tuple should be used as directory names to traverse from the root of the temporary directory to find the directory to be listed.
A forward-slash separated string, indicating the directory or subdirectory that should be traversed to from the temporary directory and listed.
recursive – If True, the directory specified will have its subdirectories recursively listed too.
- makedir(dirpath: Union[str, Tuple[str]])#
Make an empty directory at the specified path within the temporary directory. Any intermediate subdirectories that do not exist will also be created.
- Parameters:
dirpath –
The directory to create, which can be:
A tuple of strings.
A forward-slash separated string.
- Returns:
The absolute path of the created directory.
- path = None#
The absolute path of the
TempDirectory
on disk
- read(filepath: Union[str, Tuple[str]], encoding: Optional[str] = None) Union[bytes, str] #
Reads the file at the specified path within the temporary directory.
The file is always read in binary mode. Bytes will be returned unless an encoding is supplied, in which case a unicode string of the decoded data will be returned.
- write(filepath: Union[str, Tuple[str]], data: Union[bytes, str], encoding: Optional[str] = None)#
Write the supplied data to a file at the specified path within the temporary directory. Any subdirectories specified that do not exist will also be created.
The file will always be written in binary mode. The data supplied must either be bytes or an encoding must be supplied to convert the string into bytes.
- Parameters:
filepath –
The path to the file to create, which can be:
A tuple of strings.
A forward-slash separated string.
data –
bytes
containing the data to be written, or astr
ifencoding
has been supplied.encoding – The encoding to be used if data is not bytes. Should not be passed if data is already bytes.
- Returns:
The absolute path of the file written.
- testfixtures.tempdir(*args, **kw) Callable[[Callable], Callable] #
A decorator for making a
TempDirectory
available for the duration of a test function.All arguments and parameters are passed through to the
TempDirectory
constructor.
- testfixtures.generator(*args)#
A utility function for creating a generator that will yield the supplied arguments.
Helpers and Constants#
- testfixtures.diff(x: str, y: str, x_label: str = '', y_label: str = '')#
A shorthand function that uses
difflib
to return a string representing the differences between the two string arguments.Most useful when comparing multi-line strings.
- testfixtures.wrap(before: Callable[[], Any], after: Optional[Callable[[], Any]] = None)#
A decorator that causes the supplied callables to be called before or after the wrapped callable, as appropriate.
- testfixtures.not_there#
A singleton used to represent the absence of a particular attribute or parameter.
Framework Helpers#
Framework-specific helpers provided by testfixtures.
testfixtures.components#
Helpers for working with Zope and its components.
- class testfixtures.components.TestComponents#
A helper for providing a sterile registry when testing with
zope.component
.Instantiation will install an empty registry that will be returned by
zope.component.getSiteManager()
.- uninstall()#
Remove the sterile registry and replace it with the one that was in place before this
TestComponents
was instantiated.
testfixtures.django#
- testfixtures.django.compare(*args, x: ~typing.Any = <unspecified>, y: ~typing.Any = <unspecified>, expected: ~typing.Any = <unspecified>, actual: ~typing.Any = <unspecified>, prefix: ~typing.Optional[str] = None, suffix: ~typing.Optional[str] = None, x_label: ~typing.Optional[str] = None, y_label: ~typing.Optional[str] = None, raises: bool = True, recursive: bool = True, strict: bool = False, ignore_eq: bool = True, comparers: ~typing.Optional[~typing.Dict[type, ~typing.Callable[[~typing.Any, ~typing.Any, ~testfixtures.comparison.CompareContext], ~typing.Optional[str]]]] = None, **options: ~typing.Any) Optional[str] #
This is identical to
compare()
, but withignore=True
automatically set to make comparing djangoModel
instances easier.
- testfixtures.django.compare_model(x, y, context: CompareContext)#
Returns an informative string describing the differences between the two supplied Django model instances. The way in which this comparison is performed can be controlled using the following parameters:
- Parameters:
ignore_fields – A sequence of fields to ignore during comparison, most commonly set to
['id']
. By default, no fields are ignored.non_editable_fields – If True, then fields with
editable=False
will be included in the comparison. By default, these fields are ignored.
testfixtures.sybil#
- class testfixtures.sybil.FileParser(name: str)#
A Sybil parser that parses certain ReST sections to read and write files in the configured
TempDirectory
.- Parameters:
name – This is the name of the
TempDirectory
to use in the Sybil test namespace.
testfixtures.twisted#
Tools for helping to test Twisted applications.
- class testfixtures.twisted.LogCapture(fields: ~typing.Sequence[~typing.Union[str, ~typing.Callable]] = ('log_level', <function formatEvent>))#
A helper for capturing stuff logged using Twisted’s loggers.
- Parameters:
fields – A sequence of field names that
check()
will use to build “actual” events to compare against the expected events passed in. If items are strings, they will be treated as keys info the Twisted logging event. If they are callable, they will be called with the event as their only parameter. If only one field is specified, “actual” events will just be that one field; otherwise they will be a tuple of the specified fields.
- events#
The list of events captured.
- install()#
Start capturing.
- uninstall()#
Stop capturing.
- check(*expected, order_matters: bool = True)#
Check captured events against those supplied. Please see the
fields
parameter to the constructor to see how “actual” events are built.- Parameters:
order_matters – This defaults to
True
. IfFalse
, the order of expected logging versus actual logging will be ignored.
- check_failure_text(expected: str, index: int = -1, attribute: str = 'value')#
Check the string representation of an attribute of a logged
Failure
is as expected.- Parameters:
expected – The expected string representation.
index – The index into
events
where the failure should have been logged.attribute – The attribute of the failure of which to find the string representation.
- raise_logged_failure(start_index: int = 0)#
A debugging tool that raises the first failure encountered in captured logging.
- Parameters:
start_index – The index into
events
from where to start looking for failures.
- classmethod make(testcase: TestCase, **kw)#
Instantiate, install and add a cleanup for a
LogCapture
.- Parameters:
testcase – This must be an instance of
twisted.trial.unittest.TestCase
.kw – Any other parameters are passed directly to the
LogCapture
constructor.
- Returns:
The
LogCapture
instantiated by this method.
- testfixtures.twisted.DEBUG: NamedConstant = <LogLevel=debug>#
Short reference to Twisted’s
LogLevel.debug
- testfixtures.twisted.INFO: NamedConstant = <LogLevel=info>#
Short reference to Twisted’s
LogLevel.info
- testfixtures.twisted.WARN: NamedConstant = <LogLevel=warn>#
Short reference to Twisted’s
LogLevel.warn
- testfixtures.twisted.ERROR: NamedConstant = <LogLevel=error>#
Short reference to Twisted’s
LogLevel.error
- testfixtures.twisted.CRITICAL: NamedConstant = <LogLevel=critical>#
Short reference to Twisted’s
LogLevel.critical