Richer error messages.

2 files changed, 47 insertions, 3 deletions

diff --git a/lib/fixtures/_fixtures/filetree.py b/lib/fixtures/_fixtures/filetree.py
index d5ea1f9..f261fc9 100644
--- a/lib/fixtures/_fixtures/filetree.py
+++ b/lib/fixtures/_fixtures/filetree.py
@@ -30,10 +30,21 @@ def normalize_entry(entry):
         else:
             return (entry, "The file '%s'." % (entry,))
     else:
-        if entry[0][-1] == '/':
-            return (entry[0], None)
-        else:
+        if len(entry) == 1:
+            return normalize_entry(entry[0])
+        elif len(entry) == 2:
+            name, content = entry
+            is_dir = (name[-1] == '/')
+            if ((is_dir and content is not None)
+                or (not is_dir and content is None)):
+                raise ValueError(
+                    "Directories must end with '/' and have no content, "
+                    "files do not end with '/' and must have content, got %r"
+                    % (entry,))
             return entry
+        else:
+            raise ValueError(
+                "Invalid file or directory description: %r" % (entry,))
 
 
 def normalize_shape(shape):
diff --git a/lib/fixtures/tests/_fixtures/test_filetree.py b/lib/fixtures/tests/_fixtures/test_filetree.py
index 78f3c2b..cd796d6 100644
--- a/lib/fixtures/tests/_fixtures/test_filetree.py
+++ b/lib/fixtures/tests/_fixtures/test_filetree.py
@@ -112,12 +112,45 @@ class TestNormalizeEntry(TestCase):
         directory = normalize_entry('foo/')
         self.assertEqual(('foo/', None), directory)
 
+    def test_directories_with_content(self):
+        # If we're given a directory with content, we raise an error, since
+        # it's ambiguous and we don't want to guess.
+        bad_entry = ('dir/', "stuff")
+        e = self.assertRaises(ValueError, normalize_entry, bad_entry)
+        self.assertEqual(
+            "Directories must end with '/' and have no content, files do not "
+            "end with '/' and must have content, got %r" % (bad_entry,),
+            str(e))
+
     def test_filenames_as_strings(self):
         # If file names are just given as strings, then they are normalized to
         # tuples of filenames and made-up contents.
         entry = normalize_entry('foo')
         self.assertEqual(('foo', "The file 'foo'."), entry)
 
+    def test_filenames_as_singletons(self):
+        # A singleton tuple of a filename is normalized to a 2-tuple of
+        # the file name and made-up contents.
+        entry = normalize_entry(('foo',))
+        self.assertEqual(('foo', "The file 'foo'."), entry)
+
+    def test_filenames_without_content(self):
+        # If we're given a filename without content, we raise an error, since
+        # it's ambiguous and we don't want to guess.
+        bad_entry = ('filename', None)
+        e = self.assertRaises(ValueError, normalize_entry, bad_entry)
+        self.assertEqual(
+            "Directories must end with '/' and have no content, files do not "
+            "end with '/' and must have content, got %r" % (bad_entry,),
+            str(e))
+
+    def test_too_long_tuple(self):
+        bad_entry = ('foo', 'bar', 'baz')
+        e = self.assertRaises(ValueError, normalize_entry, bad_entry)
+        self.assertEqual(
+            "Invalid file or directory description: %r" % (bad_entry,),
+            str(e))
+
 
 class TestNormalizeShape(TestCase):