[paths] Document and test translate_path

The documentation was inaccurate.

Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

doc/configuration.rst

@@ -905,13 +905,12 @@ Translate Paths Settings
 ========================
 
 **translate_paths**
-    (*list*) -- list of paths to translate; format: [(path,translated_path)]
+    (*list*) -- list of paths to translate; format: ``[(path, translated_path)]``
 
 .. note::
     This feature becomes useful when you need to transform compose location
-    into e.g. a http repo which is can be passed to koji image-build.
-    Translation needs to be invoked by a function call in pungi.
-    os.path.normpath() is applied on both path and translated_path
+    into e.g. a HTTP repo which is can be passed to ``koji image-build``.
+    The ``path`` part is normalized via ``os.path.normpath()``.
     
 
 Example config

pungi/paths.py

@@ -25,6 +25,7 @@ import os
 
 from pungi.util import makedirs
 
+
 def translate_path(compose, path):
     """
     @param compose - required for access to config
@@ -36,11 +37,14 @@ def translate_path(compose, path):
     for prefix, newvalue in mapping:
         prefix = os.path.normpath(prefix)
         if normpath.startswith(prefix):
-            # don't call os.path.normpath on result since that would break http:// -> http:/ and so on
-            return normpath.replace(prefix, newvalue, 1) # replace only 1 occurance
+            # We can't call os.path.normpath on result since it is not actually
+            # a path - http:// would get changed to  http:/ and so on.
+            # Only the first occurance should be replaced.
+            return normpath.replace(prefix, newvalue, 1)
 
     return normpath
 
+
 class Paths(object):
     def __init__(self, compose):
         paths_module_name = compose.conf.get("paths_module", None)

tests/test_paths.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+import mock
+import unittest
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+
+from pungi import paths
+
+
+class TranslatePathTestCase(unittest.TestCase):
+    def test_does_nothing_without_config(self):
+        compose = mock.Mock(conf={})
+        ret = paths.translate_path(compose, '/mnt/koji/compose/rawhide/XYZ')
+        self.assertEqual(ret, '/mnt/koji/compose/rawhide/XYZ')
+
+    def test_translates_prefix(self):
+        compose = mock.Mock(conf={
+            'translate_paths': [('/mnt/koji', 'http://example.com')]
+        })
+        ret = paths.translate_path(compose, '/mnt/koji/compose/rawhide/XYZ')
+        self.assertEqual(ret, 'http://example.com/compose/rawhide/XYZ')
+
+    def test_does_not_translate_not_matching(self):
+        compose = mock.Mock(conf={
+            'translate_paths': [('/mnt/koji', 'http://example.com')]
+        })
+        ret = paths.translate_path(compose, '/mnt/fedora_koji/compose/rawhide/XYZ')
+        self.assertEqual(ret, '/mnt/fedora_koji/compose/rawhide/XYZ')
+
+
+if __name__ == "__main__":
+    unittest.main()