= Displaying recently fixed bugs =

On the Bugs frontpage, the 5 most recently fixed bugs are displayed.
There's a view class called MaloneView that helps getting the list of
bugs.

    >>> from lp.bugs.browser.bug import MaloneView
    >>> class TestMaloneView(MaloneView):
    ...     """Test version of MaloneView.
    ...
    ...     Override the user attribute, so we don't need the component
    ...     architecture set up.
    ...     """
    ...     user = None

MaloneView.getMostRecentlyFixedBugs() calls the context's searchTasks()
method, getting all the FIXRELEASED bugs, ordered by date_closed, with
the newly closed bugs first.

    >>> class FakeBugTask:
    ...     def __init__(self):
    ...         self.bug = object()

    >>> class FakeContext:
    ...     def searchTasks(self, search_params):
    ...         print "status: %s" % search_params.status.name
    ...         print "order by: %s" % search_params.orderby
    ...         return [FakeBugTask() for dummy in range(5)]
    >>> view = TestMaloneView(FakeContext(), None)
    >>> view.user = None
    >>> fixed_bugs = view.getMostRecentlyFixedBugs()
    status: FIXRELEASED
    order by: -date_closed
    >>> len(fixed_bugs)
    5

Searching through all the bug tasks can be quite slow. It's much faster
(compare 4 seconds to less than 100 ms) to limit the search, so that
only the very recently closed bugs are considered. It starts with
searching for bugs that have been closed during the last day.

    >>> import pytz
    >>> from datetime import datetime, timedelta
    >>> utc_now = datetime(2008, 8, 31, 12, 0, 0, tzinfo=pytz.timezone('UTC'))
    >>> class LimitByDateClosedContext:
    ...     def __init__(self, date_closed_limit):
    ...         self.date_closed_limit = date_closed_limit
    ...     def searchTasks(self, search_params):
    ...         print "Searching for bugs with date_closed: %s" % (
    ...             search_params.date_closed)
    ...         if (search_params.date_closed is not None and
    ...             search_params.date_closed.value < self.date_closed_limit):
    ...             return [FakeBugTask() for dummy in range(5)]
    ...         else:
    ...             return [FakeBugTask() for dummy in range(4)]
    >>> view = TestMaloneView(LimitByDateClosedContext(utc_now), None)
    >>> fixed_bugs = view.getMostRecentlyFixedBugs(when=utc_now)
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 30, 12, 0, tzinfo=<UTC>))

Since we can't guarantee that enough bugs have been closed during a
certain time period, the search is limited with regard to date_closed
using increasing ranges. If not enough bugs have been closed during the
last day, the search is increased to a week.

    >>> view = TestMaloneView(
    ...    LimitByDateClosedContext(utc_now-timedelta(days=2)), None)
    >>> fixed_bugs = view.getMostRecentlyFixedBugs(when=utc_now)
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 30, 12, 0, tzinfo=<UTC>))
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 24, 12, 0, tzinfo=<UTC>))

If not enough bugs are closed during the last week, the search is
extended to the last 30 days.

    >>> view = TestMaloneView(
    ...    LimitByDateClosedContext(utc_now-timedelta(days=8)), None)
    >>> fixed_bugs = view.getMostRecentlyFixedBugs(when=utc_now)
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 30, 12, 0, tzinfo=<UTC>))
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 24, 12, 0, tzinfo=<UTC>))
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 1, 12, 0, tzinfo=<UTC>))

And finally, if not enough bugs have been closed during the last 30
days, the date_closed limit is removed.

    >>> view = TestMaloneView(
    ...    LimitByDateClosedContext(utc_now-timedelta(days=31)), None)
    >>> fixed_bugs = view.getMostRecentlyFixedBugs(when=utc_now)
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 30, 12, 0, tzinfo=<UTC>))
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 24, 12, 0, tzinfo=<UTC>))
    Searching for bugs with date_closed:
        greater_than(datetime.datetime(2008, 8, 1, 12, 0, tzinfo=<UTC>))
    Searching for bugs with date_closed: None

It doesn't matter that less than 4 bugs were returned.

    >>> len(fixed_bugs)
    4