= Widget for entering a bug id =

The BugWidget converts string bug ids to the corresponding bug object.

    >>> from lp.services.webapp.servers import LaunchpadTestRequest
    >>> from lp.bugs.browser.widgets.bug import BugWidget
    >>> from lp.services.fields import BugField
    >>> bug_field = BugField(__name__='bug', title=u'Bug')
    >>> request = LaunchpadTestRequest(form={'field.bug': '1'})
    >>> bug_widget = BugWidget(bug_field, request)
    >>> bug_one = bug_widget.getInputValue()

    >>> from lp.bugs.interfaces.bug import IBug
    >>> IBug.providedBy(bug_one)
    True
    >>> bug_one.id
    1

If non-existant bug number is entered, an error is raised.

    >>> request = LaunchpadTestRequest(form={'field.bug': '1234567'})
    >>> bug_widget = BugWidget(bug_field, request)
    >>> bug_widget.getInputValue()
    Traceback (most recent call last):
    ...
    ConversionError: ('Not a valid bug number or nickname.', None)

It's quite common that bug ids are prefixed by '#', so such inputs are
accepted as well.

    >>> request = LaunchpadTestRequest(form={'field.bug': '#2'})
    >>> bug_widget = BugWidget(bug_field, request)
    >>> bug_two = bug_widget.getInputValue()

    >>> IBug.providedBy(bug_two)
    True
    >>> bug_two.id
    2

Leading and trailing whitespace is also stripped from the input.

    >>> request = LaunchpadTestRequest(form={'field.bug': '  #3  '})
    >>> bug_widget = BugWidget(bug_field, request)
    >>> bug_three = bug_widget.getInputValue()

    >>> IBug.providedBy(bug_three)
    True
    >>> bug_three.id
    3