:param ignore_whitespace: If set to ``True``, would not show whitespace

          changes. Defaults to ``False``.

        :param context: How many lines before/after changed lines should be

          shown. Defaults to ``3``. If negative value is passed-in, it will be

          set to ``0`` instead.

        """

        # Negative context values make no sense, and will result in

        # errors. Ensure this does not happen.

        if context < 0:

            context = 0

        if hasattr(rev1, 'raw_id'):

            rev1 = getattr(rev1, 'raw_id')

        if hasattr(rev2, 'raw_id'):

            rev2 = getattr(rev2, 'raw_id')

        # Check if given revisions are present at repository (may raise

        # ChangesetDoesNotExistError)

        if rev1 != self.EMPTY_CHANGESET:

            self.get_changeset(rev1)

        self.get_changeset(rev2)

        if path:

        else:

            file_filter = None

        return ''.join(patch.diff(self._repo, rev1, rev2, match=file_filter,

                          opts=diffopts(git=True,

                                        showfunc=True,

                                        ignorews=ignore_whitespace,

                                        context=context)))

    @classmethod

    def _check_url(cls, url, repoui=None):

        """

        Function will check given url and try to verify if it's a valid

        link. Sometimes it may happened that mercurial will issue basic

        auth request that can cause whole API to hang when used from python

        or other external calls.

        On failures it'll raise urllib2.HTTPError, exception is also thrown

        when the return code is non 200

        """

        # check first if it's not an local url

        if os.path.isdir(url) or url.startswith('file:'):

            return True

                    FileNode('foobar', content='foobar'),

                    FileNode('foobar2', content='foobar2'),

                ],

            },

            {

                'message': 'Changed foobar, added foobar3',

                'author': 'Jane Doe <jane.doe@example.com>',

                'date': datetime.datetime(2010, 1, 1, 21),

                'added': [

                    FileNode('foobar3', content='foobar3'),

                ],

                'changed': [

                    FileNode('foobar', 'FOOBAR'),

                ],

            },

            {

                'message': 'Removed foobar, changed foobar3',

                'author': 'Jane Doe <jane.doe@example.com>',

                'date': datetime.datetime(2010, 1, 1, 22),

                'changed': [

                    FileNode('foobar3', content='FOOBAR\nFOOBAR\nFOOBAR\n'),

                ],

                'removed': [FileNode('foobar')],

            },

        ]

        return commits

    def test_raise_for_wrong(self):

        with self.assertRaises(ChangesetDoesNotExistError):

            self.repo.get_diff('a' * 40, 'b' * 40)

class GitRepositoryGetDiffTest(RepositoryGetDiffTest, unittest.TestCase):

    backend_alias = 'git'

    def test_initial_commit_diff(self):

        initial_rev = self.repo.revisions[0]

        self.assertEqual(self.repo.get_diff(self.repo.EMPTY_CHANGESET, initial_rev), '''diff --git a/foobar b/foobar

new file mode 100644

index 0000000000000000000000000000000000000000..f6ea0495187600e7b2288c8ac19c5886383a4632

--- /dev/null

+++ b/foobar

@@ -0,0 +1 @@

+foobar

\ No newline at end of file

diff --git a/foobar2 b/foobar2

new file mode 100644

index 0000000000000000000000000000000000000000..e8c9d6b98e3dce993a464935e1a53f50b56a3783

--- /dev/null

+++ b/foobar2

@@ -0,0 +1 @@

+foobar2

\ No newline at end of file

''')

''')

    def test_third_changeset_diff(self):

        revs = self.repo.revisions

        self.assertEqual(self.repo.get_diff(revs[1], revs[2]), '''diff --git a/foobar b/foobar

deleted file mode 100644

index 389865bb681b358c9b102d79abd8d5f941e96551..0000000000000000000000000000000000000000

--- a/foobar

+++ /dev/null

@@ -1 +0,0 @@

-FOOBAR

\ No newline at end of file

diff --git a/foobar3 b/foobar3

index c11c37d41d33fb47741cff93fa5f9d798c1535b0..f9324477362684ff692aaf5b9a81e01b9e9a671c 100644

--- a/foobar3

+++ b/foobar3

@@ -1 +1,3 @@

-foobar3

\ No newline at end of file

+FOOBAR

+FOOBAR

+FOOBAR

''')

class HgRepositoryGetDiffTest(RepositoryGetDiffTest, unittest.TestCase):

    backend_alias = 'hg'

    def test_initial_commit_diff(self):

        initial_rev = self.repo.revisions[0]

        self.assertEqual(self.repo.get_diff(self.repo.EMPTY_CHANGESET, initial_rev), '''diff --git a/foobar b/foobar

new file mode 100644

--- /dev/null

+++ b/foobar

@@ -0,0 +1,1 @@

+foobar

\ No newline at end of file

diff --git a/foobar2 b/foobar2

new file mode 100644

--- /dev/null

+++ b/foobar2

@@ -0,0 +1,1 @@

+foobar2

\ No newline at end of file

''')

    def test_second_changeset_diff(self):

        revs = self.repo.revisions

+foobar3

\ No newline at end of file

''')

    def test_third_changeset_diff(self):

        revs = self.repo.revisions

        self.assertEqual(self.repo.get_diff(revs[1], revs[2]), '''diff --git a/foobar b/foobar

deleted file mode 100644

--- a/foobar

+++ /dev/null

@@ -1,1 +0,0 @@

-FOOBAR

\ No newline at end of file

diff --git a/foobar3 b/foobar3

--- a/foobar3

+++ b/foobar3

@@ -1,1 +1,3 @@

-foobar3

\ No newline at end of file

+FOOBAR

+FOOBAR

+FOOBAR

''')

# For each backend create test case class

for alias in SCM_TESTS:

    attrs = {

        'backend_alias': alias,

    }

    cls_name = alias.capitalize() + RepositoryBaseTest.__name__

    bases = (RepositoryBaseTest, unittest.TestCase)

    globals()[cls_name] = type(cls_name, bases, attrs)

if __name__ == '__main__':

    unittest.main()