Add SystemBranchDirectory.get_filename method

2 files changed, 18 insertions, 0 deletions

diff --git a/morphlib/sysbranchdir.py b/morphlib/sysbranchdir.py
index 7e278dce..827f150b 100644
--- a/morphlib/sysbranchdir.py
+++ b/morphlib/sysbranchdir.py
@@ -100,6 +100,15 @@ class SystemBranchDirectory(object):
 
         return os.path.join(self.root_directory, relative)
 
+    def get_filename(self, repo_url, relative):
+        '''Return full pathname to a file in a checked out repository.
+
+        This is a convenience function.
+
+        '''
+
+        return os.path.join(self.get_git_directory_name(repo_url), relative)
+
     def clone_cached_repo(self, cached_repo, checkout_ref):
         '''Clone a cached git repository into the system branch directory.
 
diff --git a/morphlib/sysbranchdir_tests.py b/morphlib/sysbranchdir_tests.py
index e75122cc..7ee04c7d 100644
--- a/morphlib/sysbranchdir_tests.py
+++ b/morphlib/sysbranchdir_tests.py
@@ -162,6 +162,15 @@ class SystemBranchDirectoryTests(unittest.TestCase):
             sb.get_git_directory_name(url),
             os.path.join(self.root_directory, stripped))
 
+    def test_reports_correct_path_for_file_in_repository(self):
+        sb = morphlib.sysbranchdir.create(
+            self.root_directory,
+            self.root_repository_url,
+            self.system_branch_name)
+        self.assertEqual(
+            sb.get_filename('test:chunk', 'foo'),
+            os.path.join(self.root_directory, 'test:chunk/foo'))
+
     def test_reports_correct_name_for_git_directory_from_file_url(self):
         stripped = 'foobar/morphs'
         url = 'file:///%s.git' % stripped