tests/test-dicthelpers.py

mq: correctly make an empty line after description in new patches

There would in some cases be an empty line between headers and the description -
that does not seem right.

There should also be an empty line between description and diff - but that was
missing.

These two mistakes would sometimes make it up for each other so we fix both at
once to just show the improvement.

Instead of writing an extra newline when writing a header line, write an extra
line when it not is written as a part of the description but is necessary
anyway.

from mercurial.dicthelpers import diff, join
import unittest
import silenttestrunner

class testdicthelpers(unittest.TestCase):
    def test_dicthelpers(self):
        # empty dicts
        self.assertEqual(diff({}, {}), {})
        self.assertEqual(join({}, {}), {})

        d1 = {}
        d1['a'] = 'foo'
        d1['b'] = 'bar'
        d1['c'] = 'baz'

        # same identity
        self.assertEqual(diff(d1, d1), {})
        self.assertEqual(join(d1, d1), {'a': ('foo', 'foo'),
                                        'b': ('bar', 'bar'),
                                        'c': ('baz', 'baz')})

        # vs empty
        self.assertEqual(diff(d1, {}), {'a': ('foo', None),
                                        'b': ('bar', None),
                                        'c': ('baz', None)})
        self.assertEqual(diff(d1, {}), {'a': ('foo', None),
                                        'b': ('bar', None),
                                        'c': ('baz', None)})

        d2 = {}
        d2['a'] = 'foo2'
        d2['b'] = 'bar'
        d2['d'] = 'quux'

        self.assertEqual(diff(d1, d2), {'a': ('foo', 'foo2'),
                                        'c': ('baz', None),
                                        'd': (None, 'quux')})
        self.assertEqual(join(d1, d2), {'a': ('foo', 'foo2'),
                                        'b': ('bar', 'bar'),
                                        'c': ('baz', None),
                                        'd': (None, 'quux')})

        # with default argument
        self.assertEqual(diff(d1, d2, 123), {'a': ('foo', 'foo2'),
                                             'c': ('baz', 123),
                                             'd': (123, 'quux')})
        self.assertEqual(join(d1, d2, 456), {'a': ('foo', 'foo2'),
                                             'b': ('bar', 'bar'),
                                             'c': ('baz', 456),
                                             'd': (456, 'quux')})

        # check that we compare against default
        self.assertEqual(diff(d1, d2, 'baz'), {'a': ('foo', 'foo2'),
                                               'd': ('baz', 'quux')})
        self.assertEqual(diff(d1, d2, 'quux'), {'a': ('foo', 'foo2'),
                                                'c': ('baz', 'quux')})

if __name__ == '__main__':
    silenttestrunner.main(__name__)