How to use pytest_terminal_summary method in Pytest

If you look closely into PyCharm sources, from the whole pytest output, PyCharm uses a single line the to parse the data for displaying in the Click to see difference dialog. This is the AssertionError: <message> line:

def test_spam():
>       assert v1 == v2
E       AssertionError: assert {'foo': 'bar'} == {'foo': 'baz'}
E         Differing items:
E         {'foo': 'bar'} != {'foo': 'baz'}
E         Use -v to get the full diff

If you want to see the full diff line without truncation, you need to customize this line in the output. For a single test, this can be done by adding a custom message to the assert statement:

def test_eggs():
    assert a == b, '{0} != {1}'.format(a, b)

If you want to apply this behaviour to all tests, define custom pytest_assertrepr_compare hook. In the conftest.py file:

# conftest.py
def pytest_assertrepr_compare(config, op, left, right):
    if op in ('==', '!='):
        return ['{0} {1} {2}'.format(left, op, right)]

The equality comparison of the values will now still be stripped when too long; to show the complete line, you still need to increase the verbosity with -vv flag.

Now the equality comparison of the values in the AssertionError line will not be stripped and the full diff is displayed in the Click to see difference dialog, highlighting the diff parts:

Use the capfd fixture.

Example:

def test_foo(capfd):
    foo()  # Writes "Hello World!" to stdout
    out, err = capfd.readouterr()
    assert out == "Hello World!"

See: http://pytest.org/en/latest/fixture.html for more details

And see: py.test --fixtures for a list of builtin fixtures.

Your example has a few problems. Here is a corrected version:

def f(name):
    print "hello {}".format(name)


def test_f(capfd):
    f("Tom")

    out, err = capfd.readouterr()
    assert out == "hello Tom\n"

Note:

• Do not use sys.stdout -- Use the capfd fixture as-is as provided by pytest.
• Run the test with: py.test foo.py

Test Run Output:

$ py.test foo.py
====================================================================== test session starts ======================================================================
platform linux2 -- Python 2.7.5 -- pytest-2.4.2
plugins: flakes, cache, pep8, cov
collected 1 items 

foo.py .

=================================================================== 1 passed in 0.01 seconds ====================================================================

Also Note:

• You do not need to run your Test Function(s) in your test modules. py.test (The CLI tool and Test Runner) does this for you.

py.test does mainly three things:

1. Collect your tests
2. Run your tests
3. Display statistics and possibly errors

By default py.test looks for (configurable iirc) test_foo.py test modules and test_foo() test functions in your test modules.

You may also consider call.excinfo in pytest_runtest_makereport:

def pytest_runtest_makereport(item, call):
    if call.when == 'setup':
        print('Called after setup for test case is executed.')
    if call.when == 'call':
        print('Called after test case is executed.')
        print('-->{}<--'.format(call.excinfo)) 
    if call.when == 'teardown':
        print('Called after teardown for test case is executed.')

The call object contains a whole bunch of additional information (test start time, stop time, etc.).

Refer: http://doc.pytest.org/en/latest/_modules/_pytest/runner.html

def pytest_runtest_makereport(item, call):
    when = call.when
    duration = call.stop-call.start
    keywords = dict([(x,1) for x in item.keywords])
    excinfo = call.excinfo
    sections = []
    if not call.excinfo:
        outcome = "passed"
        longrepr = None
    else:
        if not isinstance(excinfo, ExceptionInfo):
            outcome = "failed"
            longrepr = excinfo
        elif excinfo.errisinstance(pytest.skip.Exception):
            outcome = "skipped"
            r = excinfo._getreprcrash()
            longrepr = (str(r.path), r.lineno, r.message)
        else:
            outcome = "failed"
            if call.when == "call":
                longrepr = item.repr_failure(excinfo)
            else: # exception in setup or teardown
                longrepr = item._repr_failure_py(excinfo,
                                            style=item.config.option.tbstyle)
    for rwhen, key, content in item._report_sections:
        sections.append(("Captured %s %s" %(key, rwhen), content))
    return TestReport(item.nodeid, item.location,
                      keywords, outcome, longrepr, when,
                      sections, duration)

In order for you to modify test1 while inside a function you will need to do define test1 as a global variable, for example:

test1 = 0
def test_func():
    global test1 
    test1 += 1
test_func()

However, if you only need to read the global variable you can print it without using the keyword global, like so:

test1 = 0
def test_func():
    print(test1)
test_func()

But whenever you need to modify a global variable you must use the keyword global.

Here is 2018 (almost 2019) version:

s3 = boto3.resource('s3')
bucket = s3.Bucket('mybucket')
bucket.objects.filter(Prefix="myprefix/").delete()

Printing a progress bar isn't difficult. The common method is to use the carriage return character (\r):

from __future__ import print_function

import sys

import fcntl
import struct
import termios

class ProgressBar(object):
    def __init__(self):
        pass

    def get_terminal_width(self):
        try:
            return struct.unpack('hh', fcntl.ioctl(sys.stdout.fileno(), termios.TIOCGWINSZ, '\x00' * 4))[1]
        except IOError:
            return 120

    def display(self, percentage):
        terminal_width = self.get_terminal_width()

        stars = '*' * int((percentage / 100.0) * terminal_width)

        print(stars, end='\r')  # Print out your progress and jump to the beginning of the line
        sys.stdout.flush()      # Flush stdout to make it show up immediately

if __name__ == '__main__':
    import time
    bar = ProgressBar()

    for i in range(100):
        bar.display(i)
        time.sleep(0.03)

I'll leave it you to figure out the string manipulations you need to do to get the progress bar showing up in the middle.

I don't know why this didn't work when I tried it before, but this solution works for me now:

In test_module.py:

import logging
from module import run_function

LOGGER = logging.getLogger(__name__)

def test_func(caplog):
    LOGGER.info('Testing now.')
    run_function()
    assert 'Something bad happened!' in caplog.text

This issue is caused by an out of date version of pytest. I was able to resolve it by using pip uninstall pytest and pip install pytest one after the other to update to the lastest version of pytest.

Yes, it is possible.

If you have the test and all the fixtures in 1 file: test.py

import pytest

@pytest.fixture
def foo():
    return "foo"

@pytest.fixture
def bar(foo):
    return foo, "bar"

def test_foo_bar(bar):
    expected = ("foo", "bar")
    assert bar == expected

and run pytest test.py then Success!!!

======================================= test session starts ========================================
platform darwin -- Python 3.6.8, pytest-4.3.0
collected 1 item                                                                                   

test.py .                                                                                    [100%]

===================================== 1 passed in 0.02 seconds =====================================

But if you put the fixtures in a different file: test_foo_bar.py

from test import bar

def test_foo_bar(bar):
    expected = ("foo", "bar")
    assert bar == expected

and run pytest test_foo_bar.py expecting (like I did) that importing only the bar fixture is enough since on importing it would already have executed the foo fixture then you get the error you are getting.

======================================= test session starts ========================================
platform darwin -- Python 3.6.8, pytest-4.3.0
collected 1 item                                                                                   

test2.py E                                                                                   [100%]

============================================== ERRORS ==============================================
__________________________________ ERROR at setup of test_foo_bar __________________________________
file .../test_foo_bar.py, line 3
  def test_foo_bar(bar):
.../test.py, line 7
  @pytest.fixture
  def bar(foo):
E       fixture 'foo' not found
>       available fixtures: TIMEOUT, bar, cache, capfd, capfdbinary, caplog, capsys, capsysbinary, cov, doctest_namespace, monkeypatch, no_cover, once_without_docker, pytestconfig, record_property, record_xml_attribute, recwarn, tmp_path, tmp_path_factory, tmpdir, tmpdir_factory
>       use 'pytest --fixtures [testpath]' for help on them.

.../test.py:7
===================================== 1 error in 0.03 seconds ======================================

To fix this also import the foo fixture in the test_foo_bar.py module.