Needless message printed with --failed-first and no failed tests

[nedbat]

--failed-first always means, run all the tests, but order the recent failure to run first. But if there were no failures, it always prints a message that it is going to run all the tests. This message is not needed.

$ cat test_it.py
def test_it():
    assert 1 == 1

$ pytest
================== test session starts ===================
platform darwin -- Python 2.7.14, pytest-3.7.1, py-1.5.4, pluggy-0.7.1
rootdir: /private/tmp/failedfirst, inifile:
plugins: xdist-1.22.5, forked-0.2
collected 1 item

test_it.py .                                                                                                                                                               [100%]

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

$ pytest --failed-first
================== test session starts ===================
platform darwin -- Python 2.7.14, pytest-3.7.1, py-1.5.4, pluggy-0.7.1
rootdir: /private/tmp/failedfirst, inifile:
plugins: xdist-1.22.5, forked-0.2
collected 1 item
run-last-failure: run all (no recorded failures)

test_it.py .                                                                                                                                                               [100%]

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

$ pytest -q --failed-first
run-last-failure: run all (no recorded failures)
.                                                                                                                                                                          [100%]
1 passed in 0.01 seconds

[nicoddemus]

Hi @nedbat,

I think the idea is to make sure the plugin is actually working... I personally like to see the message to make sure there are actually no failures and now all tests are running.

[nedbat]

But whether there are failures or not, all the tests are run. Shouldn't we let the user assume the plugin is working? And show messages only when they need to know something? Can the plugin follow the -q of the main command line?

[nicoddemus]

Oh missed the bit with -q, definitely the plugin should obey -q, seems like an oversight.

When there are no more failures and the user passes --failed-first, you propose to show no message at all?

[nedbat]

Yes :)

[nicoddemus]

#3886 deals with handling -q properly, after that gets merged we can then suppress the output when there are no recorded failures on the features branch.

[dhirensr]

@nedbat @nicoddemus : I have read the complete issue and also #3886 ! does this ticket say that when --lf ,then the output now is "run-last-failure: run all (no recorded failures)" but instead it should behave exactly as --q and nothing should display?

[nicoddemus]

@dhirensr exactly! 😁

[dhirensr]

@nicoddemus : where do we change the code like do we send mode as empty string or change the print function ? could you also guide me where is the print ignored in case of --quiet ,I am not able to find that piece of code which ignores the print statement and prints nothing!

[nicoddemus]

Sorry, I'm not sure I follow your question... but all we need to do is to not print the message if there are no recorded failures, so this function:

pytest/src/_pytest/cacheprovider.py

Lines 134 to 146 in 4345efa

	def pytest_report_collectionfinish(self):
	if self.active and self.config.getoption("verbose") >= 0:
	if not self._previously_failed_count:
	mode = "run {} (no recorded failures)".format(
	self._no_failures_behavior
	)
	else:
	noun = "failure" if self._previously_failed_count == 1 else "failures"
	suffix = " first" if self.config.getoption("failedfirst") else ""
	mode = "rerun previous {count} {noun}{suffix}".format(
	count=self._previously_failed_count, suffix=suffix, noun=noun
	)
	return "run-last-failure: %s" % mode

Should be changed to:

    def pytest_report_collectionfinish(self):
        if self.active and self.config.getoption("verbose") >= 0:
            if not self._previously_failed_count:
                return None
            else:
                noun = "failure" if self._previously_failed_count == 1 else "failures"
                suffix = " first" if self.config.getoption("failedfirst") else ""
                mode = "rerun previous {count} {noun}{suffix}".format(
                    count=self._previously_failed_count, suffix=suffix, noun=noun
                )
            return "run-last-failure: %s" % mode

Or even better:

    def pytest_report_collectionfinish(self):
        if self.active and self.config.getoption("verbose") >= 0:
            if not self._previously_failed_count:
                return None

            noun = "failure" if self._previously_failed_count == 1 else "failures"
            suffix = " first" if self.config.getoption("failedfirst") else ""
            mode = "rerun previous {count} {noun}{suffix}".format(
                count=self._previously_failed_count, suffix=suffix, noun=noun
            )
            return "run-last-failure: %s" % mode

[dhirensr]

@nicoddemus : Oh yeah! that i had already fixed! I just thought I need to remove "platform linux -- Python 3.5.2, pytest-unknown, py-1.6.0, pluggy-0.7.1
rootdir: /home/dhirensr/pytest, inifile: tox.ini
collected 2 items
" also!
I thought like complete terminal should look empty that's the requirement!
I am making a PR with test! I need to mention in the document also right? Thanks a lot for helping man!

[nicoddemus]

Oh I see, thanks, but no, the idea is to remove only the "run-last-failure: run all (no recorded failures)" message.

When opening the PR, make sure to add a CHANGELOG entry and target the features branch. 👍