Writing plugins¶
It is easy to implement local conftest plugins for your own project or pip-installable plugins that can be used throughout many projects, including third party projects. Please refer to Installing and Using plugins if you only want to use but not write plugins.
A plugin contains one or multiple hook functions. Writing hooks
explains the basics and details of how you can write a hook function yourself.
pytest
implements all aspects of configuration, collection, running and
reporting by calling well specified hooks of the following plugins:
- Pytest default plugin reference: loaded from pytest’s internal
_pytest
directory. - external plugins: modules discovered through setuptools entry points
- conftest.py plugins: modules auto-discovered in test directories
In principle, each hook call is a 1:N
Python function call where N
is the
number of registered implementation functions for a given specification.
All specifications and implementations follow the pytest_
prefix
naming convention, making them easy to distinguish and find.
Plugin discovery order at tool startup¶
pytest
loads plugin modules at tool startup in the following way:
by loading all builtin plugins
by loading all plugins registered through setuptools entry points.
by pre-scanning the command line for the
-p name
option and loading the specified plugin before actual command line parsing.by loading all
conftest.py
files as inferred by the command line invocation:- if no test paths are specified use current dir as a test path
- if exists, load
conftest.py
andtest*/conftest.py
relative to the directory part of the first test path.
Note that pytest does not find
conftest.py
files in deeper nested sub directories at tool startup. It is usually a good idea to keep your conftest.py file in the top level test or project root directory.by recursively loading all plugins specified by the
pytest_plugins
variable inconftest.py
files
conftest.py: local per-directory plugins¶
Local conftest.py
plugins contain directory-specific hook
implementations. Hook Session and test running activities will
invoke all hooks defined in conftest.py
files closer to the
root of the filesystem. Example of implementing the
pytest_runtest_setup
hook so that is called for tests in the a
sub directory but not for other directories:
a/conftest.py:
def pytest_runtest_setup(item):
# called for running each test in 'a' directory
print ("setting up", item)
a/test_sub.py:
def test_sub():
pass
test_flat.py:
def test_flat():
pass
Here is how you might run it:
pytest test_flat.py # will not show "setting up"
pytest a/test_sub.py # will show "setting up"
Note
If you have conftest.py
files which do not reside in a
python package directory (i.e. one containing an __init__.py
) then
“import conftest” can be ambiguous because there might be other
conftest.py
files as well on your PYTHONPATH or sys.path
.
It is thus good practice for projects to either put conftest.py
under a package scope or to never import anything from a
conftest.py file.
Writing your own plugin¶
If you want to write a plugin, there are many real-life examples you can copy from:
- a custom collection example plugin: A basic example for specifying tests in Yaml files
- around 20 Pytest default plugin reference which provide pytest’s own functionality
- many external plugins providing additional features
All of these plugins implement the documented well specified hooks to extend and add functionality.
Note
Make sure to check out the excellent cookiecutter-pytest-plugin project, which is a cookiecutter template for authoring plugins.
The template provides an excellent starting point with a working plugin, tests running with tox, comprehensive README and entry-pointy already pre-configured.
Also consider contributing your plugin to pytest-dev once it has some happy users other than yourself.
Making your plugin installable by others¶
If you want to make your plugin externally available, you
may define a so-called entry point for your distribution so
that pytest
finds your plugin module. Entry points are
a feature that is provided by setuptools. pytest looks up
the pytest11
entrypoint to discover its
plugins and you can thus make your plugin available by defining
it in your setuptools-invocation:
# sample ./setup.py file
from setuptools import setup
setup(
name="myproject",
packages = ['myproject']
# the following makes a plugin available to pytest
entry_points = {
'pytest11': [
'name_of_plugin = myproject.pluginmodule',
]
},
# custom PyPI classifier for pytest plugins
classifiers=[
"Framework :: Pytest",
],
)
If a package is installed this way, pytest
will load
myproject.pluginmodule
as a plugin which can define
well specified hooks.
Note
Make sure to include Framework :: Pytest
in your list of
PyPI classifiers
to make it easy for users to find your plugin.
Assertion Rewriting¶
One of the main features of pytest
is the use of plain assert
statements and the detailed introspection of expressions upon
assertion failures. This is provided by “assertion rewriting” which
modifies the parsed AST before it gets compiled to bytecode. This is
done via a PEP 302 import hook which gets installed early on when
pytest
starts up and will perform this re-writing when modules get
imported. However since we do not want to test different bytecode
then you will run in production this hook only re-writes test modules
themselves as well as any modules which are part of plugins. Any
other imported module will not be re-written and normal assertion
behaviour will happen.
If you have assertion helpers in other modules where you would need
assertion rewriting to be enabled you need to ask pytest
explicitly to re-write this module before it gets imported.
-
register_assert_rewrite
(*names)[source]¶ Register one or more module names to be rewritten on import.
This function will make sure that this module or all modules inside the package will get their assert statements rewritten. Thus you should make sure to call this before the module is actually imported, usually in your __init__.py if you are a plugin using a package.
Raises: TypeError – if the given module names are not strings.
This is especially important when you write a pytest plugin which is
created using a package. The import hook only treats conftest.py
files and any modules which are listed in the pytest11
entrypoint
as plugins. As an example consider the following package:
pytest_foo/__init__.py
pytest_foo/plugin.py
pytest_foo/helper.py
With the following typical setup.py
extract:
setup(
...
entry_points={'pytest11': ['foo = pytest_foo.plugin']},
...
)
In this case only pytest_foo/plugin.py
will be re-written. If the
helper module also contains assert statements which need to be
re-written it needs to be marked as such, before it gets imported.
This is easiest by marking it for re-writing inside the
__init__.py
module, which will always be imported first when a
module inside a package is imported. This way plugin.py
can still
import helper.py
normally. The contents of
pytest_foo/__init__.py
will then need to look like this:
import pytest
pytest.register_assert_rewrite('pytest_foo.helper')
Requiring/Loading plugins in a test module or conftest file¶
You can require plugins in a test module or a conftest.py
file like this:
pytest_plugins = ["name1", "name2"]
When the test module or conftest plugin is loaded the specified plugins will be loaded as well. Any module can be blessed as a plugin, including internal application modules:
pytest_plugins = "myapp.testsupport.myplugin"
pytest_plugins
variables are processed recursively, so note that in the example above
if myapp.testsupport.myplugin
also declares pytest_plugins
, the contents
of the variable will also be loaded as plugins, and so on.
This mechanism makes it easy to share fixtures within applications or even
external applications without the need to create external plugins using
the setuptools
’s entry point technique.
Plugins imported by pytest_plugins
will also automatically be marked
for assertion rewriting (see pytest.register_assert_rewrite()
).
However for this to have any effect the module must not be
imported already; if it was already imported at the time the
pytest_plugins
statement is processed, a warning will result and
assertions inside the plugin will not be re-written. To fix this you
can either call pytest.register_assert_rewrite()
yourself before
the module is imported, or you can arrange the code to delay the
importing until after the plugin is registered.
Accessing another plugin by name¶
If a plugin wants to collaborate with code from another plugin it can obtain a reference through the plugin manager like this:
plugin = config.pluginmanager.getplugin("name_of_plugin")
If you want to look at the names of existing plugins, use
the --trace-config
option.
Testing plugins¶
pytest comes with some facilities that you can enable for testing your
plugin. Given that you have an installed plugin you can enable the
testdir
fixture via specifying a
command line option to include the pytester plugin (-p pytester
) or
by putting pytest_plugins = "pytester"
into your test or
conftest.py
file. You then will have a testdir
fixture which you
can use like this:
# content of test_myplugin.py
pytest_plugins = "pytester" # to get testdir fixture
def test_myplugin(testdir):
testdir.makepyfile("""
def test_example():
pass
""")
result = testdir.runpytest("--verbose")
result.stdout.fnmatch_lines("""
test_example*
""")
Note that by default testdir.runpytest()
will perform a pytest
in-process. You can pass the command line option --runpytest=subprocess
to have it happen in a subprocess.
Also see the RunResult
for more
methods of the result object that you get from a call to runpytest
.
Writing hook functions¶
hook function validation and execution¶
pytest calls hook functions from registered plugins for any
given hook specification. Let’s look at a typical hook function
for the pytest_collection_modifyitems(session, config,
items)
hook which pytest calls after collection of all test items is
completed.
When we implement a pytest_collection_modifyitems
function in our plugin
pytest will during registration verify that you use argument
names which match the specification and bail out if not.
Let’s look at a possible implementation:
def pytest_collection_modifyitems(config, items):
# called after collection is completed
# you can modify the ``items`` list
Here, pytest
will pass in config
(the pytest config object)
and items
(the list of collected test items) but will not pass
in the session
argument because we didn’t list it in the function
signature. This dynamic “pruning” of arguments allows pytest
to
be “future-compatible”: we can introduce new hook named parameters without
breaking the signatures of existing hook implementations. It is one of
the reasons for the general long-lived compatibility of pytest plugins.
Note that hook functions other than pytest_runtest_*
are not
allowed to raise exceptions. Doing so will break the pytest run.
firstresult: stop at first non-None result¶
Most calls to pytest
hooks result in a list of results which contains
all non-None results of the called hook functions.
Some hook specifications use the firstresult=True
option so that the hook
call only executes until the first of N registered functions returns a
non-None result which is then taken as result of the overall hook call.
The remaining hook functions will not be called in this case.
hookwrapper: executing around other hooks¶
New in version 2.7.
pytest plugins can implement hook wrappers which wrap the execution of other hook implementations. A hook wrapper is a generator function which yields exactly once. When pytest invokes hooks it first executes hook wrappers and passes the same arguments as to the regular hooks.
At the yield point of the hook wrapper pytest will execute the next hook
implementations and return their result to the yield point in the form of
a CallOutcome
instance which encapsulates a result or
exception info. The yield point itself will thus typically not raise
exceptions (unless there are bugs).
Here is an example definition of a hook wrapper:
import pytest
@pytest.hookimpl(hookwrapper=True)
def pytest_pyfunc_call(pyfuncitem):
# do whatever you want before the next hook executes
outcome = yield
# outcome.excinfo may be None or a (cls, val, tb) tuple
res = outcome.get_result() # will raise if outcome was exception
# postprocess result
Note that hook wrappers don’t return results themselves, they merely perform tracing or other side effects around the actual hook implementations. If the result of the underlying hook is a mutable object, they may modify that result but it’s probably better to avoid it.
Hook function ordering / call example¶
For any given hook specification there may be more than one
implementation and we thus generally view hook
execution as a
1:N
function call where N
is the number of registered functions.
There are ways to influence if a hook implementation comes before or
after others, i.e. the position in the N
-sized list of functions:
# Plugin 1
@pytest.hookimpl(tryfirst=True)
def pytest_collection_modifyitems(items):
# will execute as early as possible
# Plugin 2
@pytest.hookimpl(trylast=True)
def pytest_collection_modifyitems(items):
# will execute as late as possible
# Plugin 3
@pytest.hookimpl(hookwrapper=True)
def pytest_collection_modifyitems(items):
# will execute even before the tryfirst one above!
outcome = yield
# will execute after all non-hookwrappers executed
Here is the order of execution:
- Plugin3’s pytest_collection_modifyitems called until the yield point because it is a hook wrapper.
- Plugin1’s pytest_collection_modifyitems is called because it is marked
with
tryfirst=True
. - Plugin2’s pytest_collection_modifyitems is called because it is marked
with
trylast=True
(but even without this mark it would come after Plugin1). - Plugin3’s pytest_collection_modifyitems then executing the code after the yield
point. The yield receives a
CallOutcome
instance which encapsulates the result from calling the non-wrappers. Wrappers shall not modify the result.
It’s possible to use tryfirst
and trylast
also in conjunction with
hookwrapper=True
in which case it will influence the ordering of hookwrappers
among each other.
Declaring new hooks¶
Plugins and conftest.py
files may declare new hooks that can then be
implemented by other plugins in order to alter behaviour or interact with
the new plugin:
-
pytest_addhooks
(pluginmanager)[source]¶ called at plugin registration time to allow adding new hooks via a call to pluginmanager.add_hookspecs(module_or_class, prefix).
Hooks are usually declared as do-nothing functions that contain only documentation describing when the hook will be called and what return values are expected.
For an example, see newhooks.py from xdist.
Optionally using hooks from 3rd party plugins¶
Using new hooks from plugins as explained above might be a little tricky because of the standard validation mechanism: if you depend on a plugin that is not installed, validation will fail and the error message will not make much sense to your users.
One approach is to defer the hook implementation to a new plugin instead of declaring the hook functions directly in your plugin module, for example:
# contents of myplugin.py
class DeferPlugin(object):
"""Simple plugin to defer pytest-xdist hook functions."""
def pytest_testnodedown(self, node, error):
"""standard xdist hook function.
"""
def pytest_configure(config):
if config.pluginmanager.hasplugin('xdist'):
config.pluginmanager.register(DeferPlugin())
This has the added benefit of allowing you to conditionally install hooks depending on which plugins are installed.
pytest hook reference¶
Initialization, command line and configuration hooks¶
-
pytest_load_initial_conftests
(early_config, parser, args)[source]¶ implements the loading of initial conftest files ahead of command line option parsing.
-
pytest_cmdline_preparse
(config, args)[source]¶ (deprecated) modify command line arguments before option parsing.
-
pytest_cmdline_parse
(pluginmanager, args)[source]¶ return initialized config object, parsing the specified args.
Stops at first non-None result, see firstresult: stop at first non-None result
-
pytest_addoption
(parser)[source]¶ register argparse-style options and ini-style config values, called once at the beginning of a test run.
Note
This function should be implemented only in plugins or
conftest.py
files situated at the tests root directory due to how pytest discovers plugins during startup.Parameters: parser – To add command line options, call parser.addoption(...)
. To add ini-file values callparser.addini(...)
.Options can later be accessed through the
config
object, respectively:config.getoption(name)
to retrieve the value of a command line option.config.getini(name)
to retrieve a value read from an ini-style file.
The config object is passed around on many internal objects via the
.config
attribute or can be retrieved as thepytestconfig
fixture or accessed via (deprecated)pytest.config
.
-
pytest_cmdline_main
(config)[source]¶ called for performing the main command line action. The default implementation will invoke the configure hooks and runtest_mainloop.
Stops at first non-None result, see firstresult: stop at first non-None result
Generic “runtest” hooks¶
All runtest related hooks receive a pytest.Item
object.
-
pytest_runtest_protocol
(item, nextitem)[source]¶ implements the runtest_setup/call/teardown protocol for the given test item, including capturing exceptions and calling reporting hooks.
Parameters: - item – test item for which the runtest protocol is performed.
- nextitem – the scheduled-to-be-next test item (or None if this
is the end my friend). This argument is passed on to
pytest_runtest_teardown()
.
Return boolean: True if no further hook implementations should be invoked.
Stops at first non-None result, see firstresult: stop at first non-None result
-
pytest_runtest_teardown
(item, nextitem)[source]¶ called after
pytest_runtest_call
.Parameters: nextitem – the scheduled-to-be-next test item (None if no further test item is scheduled). This argument can be used to perform exact teardowns, i.e. calling just enough finalizers so that nextitem only needs to call setup-functions.
-
pytest_runtest_makereport
(item, call)[source]¶ return a
_pytest.runner.TestReport
object for the givenpytest.Item
and_pytest.runner.CallInfo
.Stops at first non-None result, see firstresult: stop at first non-None result
For deeper understanding you may look at the default implementation of
these hooks in _pytest.runner
and maybe also
in _pytest.pdb
which interacts with _pytest.capture
and its input/output capturing in order to immediately drop
into interactive debugging when a test failure occurs.
The _pytest.terminal
reported specifically uses
the reporting hook to print information about a test run.
Collection hooks¶
pytest
calls the following hooks for collecting files and directories:
-
pytest_ignore_collect
(path, config)[source]¶ return True to prevent considering this path for collection. This hook is consulted for all files and directories prior to calling more specific hooks.
Stops at first non-None result, see firstresult: stop at first non-None result
-
pytest_collect_directory
(path, parent)[source]¶ called before traversing a directory for collection files.
Stops at first non-None result, see firstresult: stop at first non-None result
-
pytest_collect_file
(path, parent)[source]¶ return collection Node or None for the given path. Any new node needs to have the specified
parent
as a parent.
For influencing the collection of objects in Python modules you can use the following hook:
-
pytest_pycollect_makeitem
(collector, name, obj)[source]¶ return custom item/collector for a python object in a module, or None.
Stops at first non-None result, see firstresult: stop at first non-None result
-
pytest_make_parametrize_id
(config, val, argname)[source]¶ Return a user-friendly string representation of the given
val
that will be used by @pytest.mark.parametrize calls. Return None if the hook doesn’t know aboutval
. The parameter name is available asargname
, if required.Stops at first non-None result, see firstresult: stop at first non-None result
After collection is complete, you can modify the order of items, delete or otherwise amend the test items:
Reporting hooks¶
Session related reporting hooks:
-
pytest_report_header
(config, startdir)[source]¶ return a string to be displayed as header info for terminal reporting.
Note
This function should be implemented only in plugins or
conftest.py
files situated at the tests root directory due to how pytest discovers plugins during startup.
-
pytest_report_teststatus
(report)[source]¶ return result-category, shortletter and verbose word for reporting.
Stops at first non-None result, see firstresult: stop at first non-None result
-
pytest_terminal_summary
(terminalreporter, exitstatus)[source]¶ add additional section in terminal summary reporting.
-
pytest_fixture_setup
(fixturedef, request)[source]¶ performs fixture setup execution.
Stops at first non-None result, see firstresult: stop at first non-None result
-
pytest_fixture_post_finalizer
(fixturedef)[source]¶ called after fixture teardown, but before the cache is cleared so the fixture result cache
fixturedef.cached_result
can still be accessed.
And here is the central hook for reporting about test execution:
-
pytest_runtest_logreport
(report)[source]¶ process a test setup/call/teardown report relating to the respective phase of executing a test.
You can also use this hook to customize assertion representation for some types:
-
pytest_assertrepr_compare
(config, op, left, right)[source]¶ return explanation for comparisons in failing assert expressions.
Return None for no custom explanation, otherwise return a list of strings. The strings will be joined by newlines but any newlines in a string will be escaped. Note that all but the first line will be indented slightly, the intention is for the first line to be a summary.
Debugging/Interaction hooks¶
There are few hooks which can be used for special reporting or interaction with exceptions:
-
pytest_exception_interact
(node, call, report)[source]¶ called when an exception was raised which can potentially be interactively handled.
This hook is only called if an exception was raised that is not an internal exception like
skip.Exception
.
-
pytest_enter_pdb
(config)[source]¶ called upon pdb.set_trace(), can be used by plugins to take special action just before the python debugger enters in interactive mode.
Parameters: config (_pytest.config.Config) – pytest config object
Reference of objects involved in hooks¶
-
class
Config
[source]¶ access to configuration values, pluginmanager and plugin hooks.
-
option
= None¶ access to command line option as attributes. (deprecated), use
getoption()
instead
-
pluginmanager
= None¶ a pluginmanager instance
-
add_cleanup
(func)[source]¶ Add a function to be called when the config object gets out of use (usually coninciding with pytest_unconfigure).
-
warn
(code, message, fslocation=None, nodeid=None)[source]¶ generate a warning for this test session.
-
addinivalue_line
(name, line)[source]¶ add a line to an ini-file option. The option must have been declared but might not yet be set in which case the line becomes the the first line in its value.
-
getini
(name)[source]¶ return configuration value from an ini file. If the specified name hasn’t been registered through a prior
parser.addini
call (usually from a plugin), a ValueError is raised.
-
getoption
(name, default=<NOTSET>, skip=False)[source]¶ return command line option value.
Parameters: - name – name of the option. You may also specify
the literal
--OPT
option instead of the “dest” option name. - default – default value if no option of that name exists.
- skip – if True raise pytest.skip if option does not exists or has a None value.
- name – name of the option. You may also specify
the literal
-
-
class
Parser
[source]¶ Parser for command line arguments and ini-file values.
Variables: extra_info – dict of generic param -> value to display in case there’s an error processing the command line arguments. -
getgroup
(name, description='', after=None)[source]¶ get (or create) a named option Group.
Name: name of the option group. Description: long description for –help output. After: name of other group, used for ordering –help output. The returned group object has an
addoption
method with the same signature asparser.addoption
but will be shown in the respective group in the output ofpytest. --help
.
-
addoption
(*opts, **attrs)[source]¶ register a command line option.
Opts: option names, can be short or long options. Attrs: same attributes which the add_option()
function of the argparse library accepts.After command line parsing options are available on the pytest config object via
config.option.NAME
whereNAME
is usually set by passing adest
attribute, for exampleaddoption("--long", dest="NAME", ...)
.
-
parse_known_args
(args, namespace=None)[source]¶ parses and returns a namespace object with known arguments at this point.
-
parse_known_and_unknown_args
(args, namespace=None)[source]¶ parses and returns a namespace object with known arguments, and the remaining arguments unknown at this point.
-
addini
(name, help, type=None, default=None)[source]¶ register an ini-file option.
Name: name of the ini-variable Type: type of the variable, can be pathlist
,args
,linelist
orbool
.Default: default value if no ini-file option exists but is queried. The value of ini-variables can be retrieved via a call to
config.getini(name)
.
-
-
class
Node
[source]¶ base class for Collector and Item the test collection tree. Collector subclasses have children, Items are terminal nodes.
-
name
= None¶ a unique name within the scope of the parent node
-
parent
= None¶ the parent collector node.
-
config
= None¶ the pytest config object
-
session
= None¶ the session this node is part of
-
fspath
= None¶ filesystem path where this node was collected from (can be None)
-
keywords
= None¶ keywords/markers collected from all scopes
-
extra_keyword_matches
= None¶ allow adding of extra keywords to use for matching
-
ihook
¶ fspath sensitive hook proxy used to call pytest hooks
-
nodeid
¶ a ::-separated string denoting its collection tree address.
-
listchain
()[source]¶ return list of all parent collectors up to self, starting from root of collection tree.
-
add_marker
(marker)[source]¶ dynamically add a marker object to the node.
marker
can be a string or pytest.mark.* instance.
-
get_marker
(name)[source]¶ get a marker object from this node or None if the node doesn’t have a marker with that name.
-
-
class
Collector
[source]¶ Bases:
_pytest.main.Node
Collector instances create children through collect() and thus iteratively build a tree.
-
exception
CollectError
[source]¶ Bases:
exceptions.Exception
an error during collection, contains a custom message.
-
exception
-
class
Item
[source]¶ Bases:
_pytest.main.Node
a basic test invocation item. Note that for a single function there might be multiple test invocation items.
-
class
Module
[source]¶ Bases:
_pytest.main.File
,_pytest.python.PyCollector
Collector for test classes and functions.
-
class
Function
[source]¶ Bases:
_pytest.python.FunctionMixin
,_pytest.main.Item
,_pytest.compat.FuncargnamesCompatAttr
a Function Item is responsible for setting up and executing a Python test function.
-
originalname
= None¶ original function name, without any decorations (for example parametrization adds a
"[...]"
suffix to function names).New in version 3.0.
-
function
¶ underlying python ‘function’ object
-
-
class
CallInfo
[source]¶ Result/Exception info a function invocation.
-
when
= None¶ context of invocation: one of “setup”, “call”, “teardown”, “memocollect”
-
excinfo
= None¶ None or ExceptionInfo object.
-
-
class
TestReport
[source]¶ Basic test report object (also used for setup and teardown calls if they fail).
-
nodeid
= None¶ normalized collection node id
-
location
= None¶ a (filesystempath, lineno, domaininfo) tuple indicating the actual location of a test item - it might be different from the collected one e.g. if a method is inherited from a different module.
-
keywords
= None¶ a name -> value dictionary containing all keywords and markers associated with a test invocation.
-
outcome
= None¶ test outcome, always one of “passed”, “failed”, “skipped”.
-
longrepr
= None¶ None or a failure representation.
-
when
= None¶ one of ‘setup’, ‘call’, ‘teardown’ to indicate runtest phase.
-
sections
= None¶ list of pairs
(str, str)
of extra information which needs to marshallable. Used by pytest to add captured text fromstdout
andstderr
, but may be used by other plugins to add arbitrary information to reports.
-
duration
= None¶ time it took to run just the test
-
capstderr
¶ Return captured text from stderr, if capturing is enabled
New in version 3.0.
-
capstdout
¶ Return captured text from stdout, if capturing is enabled
New in version 3.0.
-
longreprtext
¶ Read-only property that returns the full string representation of
longrepr
.New in version 3.0.
-
-
class
_CallOutcome
[source]¶ Outcome of a function call, either an exception or a proper result. Calling the
get_result
method will return the result or reraise the exception raised when the function was called.
-
get_plugin_manager
()[source]¶ Obtain a new instance of the
_pytest.config.PytestPluginManager
, with default plugins already loaded.This function can be used by integration with other tools, like hooking into pytest to run tests into an IDE.
-
class
PytestPluginManager
[source]¶ Bases:
_pytest.vendored_packages.pluggy.PluginManager
Overwrites
pluggy.PluginManager
to add pytest-specific functionality:- loading plugins from the command line,
PYTEST_PLUGIN
env variable andpytest_plugins
global variables found in plugins being loaded; conftest.py
loading during start-up;
-
addhooks
(module_or_class)[source]¶ Deprecated since version 2.8.
Use
pluggy.PluginManager.add_hookspecs
instead.
- loading plugins from the command line,
-
class
PluginManager
[source]¶ Core Pluginmanager class which manages registration of plugin objects and 1:N hook calling.
You can register new hooks by calling
add_hookspec(module_or_class)
. You can register plugin objects (which contain hooks) by callingregister(plugin)
. The Pluginmanager is initialized with a prefix that is searched for in the names of the dict of registered plugin objects. An optional excludefunc allows to blacklist names which are not considered as hooks despite a matching prefix.For debugging purposes you can call
enable_tracing()
which will subsequently send debug information to the trace helper.-
register
(plugin, name=None)[source]¶ Register a plugin and return its canonical name or None if the name is blocked from registering. Raise a ValueError if the plugin is already registered.
-
unregister
(plugin=None, name=None)[source]¶ unregister a plugin object and all its contained hook implementations from internal data structures.
-
add_hookspecs
(module_or_class)[source]¶ add new hook specifications defined in the given module_or_class. Functions are recognized if they have been decorated accordingly.
-
get_canonical_name
(plugin)[source]¶ Return canonical name for a plugin object. Note that a plugin may be registered under a different name which was specified by the caller of register(plugin, name). To obtain the name of an registered plugin use
get_name(plugin)
instead.
-
check_pending
()[source]¶ Verify that all hooks which have not been verified against a hook specification are optional, otherwise raise PluginValidationError
-
load_setuptools_entrypoints
(entrypoint_name)[source]¶ Load modules from querying the specified setuptools entrypoint name. Return the number of loaded plugins.
-
list_plugin_distinfo
()[source]¶ return list of distinfo/plugin tuples for all setuptools registered plugins.
-
add_hookcall_monitoring
(before, after)[source]¶ add before/after tracing functions for all hooks and return an undo function which, when called, will remove the added tracers.
before(hook_name, hook_impls, kwargs)
will be called ahead of all hook calls and receive a hookcaller instance, a list of HookImpl instances and the keyword arguments for the hook call.after(outcome, hook_name, hook_impls, kwargs)
receives the same arguments asbefore
but also a_CallOutcome
object which represents the result of the overall hook call.
-
-
class
Testdir
[source]¶ Temporary test directory with tools to test/run pytest itself.
This is based on the
tmpdir
fixture but provides a number of methods which aid with testing pytest itself. Unlesschdir()
is used all methods will usetmpdir
as current working directory.Attributes:
Tmpdir: The py.path.local
instance of the temporary directory.Plugins: A list of plugins to use with parseconfig()
andrunpytest()
. Initially this is an empty list but plugins can be added to the list. The type of items to add to the list depend on the method which uses them so refer to them for details.-
runpytest
(*args, **kwargs)[source]¶ Run pytest inline or in a subprocess, depending on the command line option “–runpytest” and return a
RunResult
.
-
runpytest_inprocess
(*args, **kwargs)[source]¶ Return result of running pytest in-process, providing a similar interface to what self.runpytest() provides.
-
runpytest_subprocess
(*args, **kwargs)[source]¶ Run pytest as a subprocess with given arguments.
Any plugins added to the
plugins
list will added using the-p
command line option. Addtionally--basetemp
is used put any temporary files and directories in a numbered directory prefixed with “runpytest-” so they do not conflict with the normal numberd pytest location for temporary files and directories.Returns a
RunResult
.
-
-
class
RunResult
[source]¶ The result of running a command.
Attributes:
Ret: The return value. Outlines: List of lines captured from stdout. Errlines: List of lines captures from stderr. Stdout: LineMatcher
of stdout, usestdout.str()
to reconstruct stdout or the commonly usedstdout.fnmatch_lines()
method.Stderrr: LineMatcher
of stderr.Duration: Duration in seconds.
-
class
LineMatcher
[source]¶ Flexible matching of text.
This is a convenience class to test large texts like the output of commands.
The constructor takes a list of lines without their trailing newlines, i.e.
text.splitlines()
.-
fnmatch_lines
(lines2)[source]¶ Search the text for matching lines.
The argument is a list of lines which have to match and can use glob wildcards. If they do not match an pytest.fail() is called. The matches and non-matches are also printed on stdout.
-
fnmatch_lines_random
(lines2)[source]¶ Check lines exist in the output.
The argument is a list of lines which have to occur in the output, in any order. Each line can contain glob whildcards.
-