Improve default locale path discovering.

src/humanize/i18n.py

@@ -7,11 +7,14 @@
 _TRANSLATIONS = {None: gettext_module.NullTranslations()}
 _CURRENT = local()
 
-try:
-    _DEFAULT_LOCALE_PATH = os.path.join(os.path.dirname(__file__), "locale")
-except AttributeError:
-    # in case that __file__ does not exist
-    _DEFAULT_LOCALE_PATH = None
+
+def _get_default_locale_path():
+    try:
+        if __file__ is None:
+            return None
+        return os.path.join(os.path.dirname(__file__), "locale")
+    except NameError:
+        return None
 
 
 def get_translation():
@@ -26,7 +29,7 @@ def activate(locale, path=None):
     @param locale: language name, eg 'en_GB'
     @param path: path to search for locales"""
     if path is None:
-        path = _DEFAULT_LOCALE_PATH
+        path = _get_default_locale_path()
 
     if path is None:
         raise Exception(

tests/test_i18n.py

@@ -1,6 +1,8 @@
 import datetime as dt
+import importlib
 
 import humanize
+import pytest
 
 
 def test_i18n():
@@ -17,3 +19,43 @@ def test_i18n():
         humanize.i18n.deactivate()
         assert humanize.naturaltime(three_seconds) == "3 seconds ago"
         assert humanize.ordinal(5) == "5th"
+
+
+def test_default_locale_path_defined__file__():
+    i18n = importlib.import_module("humanize.i18n")
+    assert i18n._get_default_locale_path() is not None
+
+
+def test_default_locale_path_null__file__():
+    i18n = importlib.import_module("humanize.i18n")
+    i18n.__file__ = None
+    assert i18n._get_default_locale_path() is None
+
+
+def test_default_locale_path_undefined__file__():
+    i18n = importlib.import_module("humanize.i18n")
+    del i18n.__file__
+    i18n._get_default_locale_path() is None
+
+
+class TestActivate:
+    expected_msg = (
+        "Humanize cannot determinate the default location of the"
+        " 'locale' folder. You need to pass the path explicitly."
+    )
+
+    def test_default_locale_path_null__file__(self):
+        i18n = importlib.import_module("humanize.i18n")
+        i18n.__file__ = None
+
+        with pytest.raises(Exception) as excinfo:
+            i18n.activate("ru_RU")
+        assert str(excinfo.value) == self.expected_msg
+
+    def test_default_locale_path_undefined__file__(self):
+        i18n = importlib.import_module("humanize.i18n")
+        del i18n.__file__
+
+        with pytest.raises(Exception) as excinfo:
+            i18n.activate("ru_RU")
+        assert str(excinfo.value) == self.expected_msg