Add basic test for in_directory.

lib/galaxy/util/__init__.py

@@ -609,6 +609,20 @@ def in_directory( file, directory, local_path_module=os.path ):
 
     local_path_module is used by Pulsar to check Windows paths while running on
     a POSIX-like system.
+
+    >>> base_dir = tempfile.mkdtemp()
+    >>> safe_dir = os.path.join(base_dir, "user")
+    >>> os.mkdir(safe_dir)
+    >>> good_file = os.path.join(safe_dir, "1")
+    >>> with open(good_file, "w") as f: f.write("hello")
+    >>> in_directory(good_file, safe_dir)
+    True
+    >>> in_directory("/other/file/is/here.txt", safe_dir)
+    False
+    >>> unsafe_link = os.path.join(safe_dir, "2")
+    >>> os.symlink("/other/file/bad.fasta", unsafe_link)
+    >>> in_directory(unsafe_link, safe_dir)
+    False
     """
     if local_path_module != os.path:
         _safe_contains = importlib.import_module('galaxy.util.path.%s' % local_path_module.__name__).safe_contains