# unit tests for mercuril.util utilities

import contextlib

import io

import itertools

import unittest

from mercurial import pycompat, util, utils

@contextlib.contextmanager

def mocktimer(incr=0.1, *additional_targets):

    """Replaces util.timer and additional_targets with a mock

    The timer starts at 0. On each call the time incremented by the value

    of incr. If incr is an iterable, then the time is incremented by the

    next value from that iterable, looping in a cycle when reaching the end.

    additional_targets must be a sequence of (object, attribute_name) tuples;

    the mock is set with setattr(object, attribute_name, mock).

    """

    time = [0]

    try:

        incr = itertools.cycle(incr)

    except TypeError:

        incr = itertools.repeat(incr)

    def timer():

        time[0] += next(incr)

        return time[0]

    # record original values

    orig = util.timer

    additional_origs = [(o, a, getattr(o, a)) for o, a in additional_targets]

    # mock out targets

    util.timer = timer

    for obj, attr in additional_targets:

        setattr(obj, attr, timer)

    try:

        yield

    finally:

        # restore originals

        util.timer = orig

        for args in additional_origs:

            setattr(*args)

# attr.s default factory for util.timedstats.start binds the timer we

# need to mock out.

_start_default = (util.timedcmstats.start.default, 'factory')

@contextlib.contextmanager

def capturestderr():

    """Replace utils.procutil.stderr with an io.BytesIO instance

    The instance is made available as the return value of __enter__.

    This contextmanager is reentrant.

    """

    orig = utils.procutil.stderr

    utils.procutil.stderr = io.BytesIO()

    try:

        yield utils.procutil.stderr

    finally:

        utils.procutil.stderr = orig

class timedtests(unittest.TestCase):

    def testtimedcmstatsstr(self):

        stats = util.timedcmstats()

        self.assertEqual(str(stats), '<unknown>')

        self.assertEqual(bytes(stats), b'<unknown>')

        stats.elapsed = 12.34

        self.assertEqual(str(stats), pycompat.sysstr(util.timecount(12.34)))

        self.assertEqual(bytes(stats), util.timecount(12.34))

    def testtimedcmcleanexit(self):

        # timestamps 1, 4, elapsed time of 4 - 1 = 3

        with mocktimer([1, 3], _start_default):

            with util.timedcm('pass') as stats:

                # actual context doesn't matter

                pass

        self.assertEqual(stats.start, 1)

        self.assertEqual(stats.elapsed, 3)

        self.assertEqual(stats.level, 1)

    def testtimedcmnested(self):

        # timestamps 1, 3, 6, 10, elapsed times of 6 - 3 = 3 and 10 - 1 = 9

        with mocktimer([1, 2, 3, 4], _start_default):

            with util.timedcm('outer') as outer_stats:

                with util.timedcm('inner') as inner_stats:

                    # actual context doesn't matter

                    pass

        self.assertEqual(outer_stats.start, 1)

        self.assertEqual(outer_stats.elapsed, 9)

        self.assertEqual(outer_stats.level, 1)

        self.assertEqual(inner_stats.start, 3)

        self.assertEqual(inner_stats.elapsed, 3)

        self.assertEqual(inner_stats.level, 2)

    def testtimedcmexception(self):

        # timestamps 1, 4, elapsed time of 4 - 1 = 3

        with mocktimer([1, 3], _start_default):

            try:

                with util.timedcm('exceptional') as stats:

                    raise ValueError()

            except ValueError:

                pass

        self.assertEqual(stats.start, 1)

        self.assertEqual(stats.elapsed, 3)

        self.assertEqual(stats.level, 1)

    def testtimeddecorator(self):

        @util.timed

        def testfunc(callcount=1):

            callcount -= 1

            if callcount:

                testfunc(callcount)

        # timestamps 1, 2, 3, 4, elapsed time of 3 - 2 = 1 and 4 - 1 = 3

        with mocktimer(1, _start_default):

            with capturestderr() as out:

                testfunc(2)

        self.assertEqual(

            out.getvalue(),

            (b'    testfunc: 1.000 s\n' b'  testfunc: 3.000 s\n'),

        )

if __name__ == '__main__':

    import silenttestrunner

    silenttestrunner.main(__name__)