pytests: add helper to grab a directory from environment

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/python/samba/tests/__init__.py b/python/samba/tests/__init__.py
index f117d0b1341969281ef83f606af67878721690d4..09c70aab134604a6e8a42a06517b3a935bc38ae6 100644 (file)
--- a/python/samba/tests/__init__.py
+++ b/python/samba/tests/__init__.py
@@ -704,3 +704,19 @@ def check_help_consistency(out,
 
     if errors:
         return "\n".join(errors)
+
+
+def get_env_dir(key):
+    """A helper to pull a directory name from the environment, used in
+    some tests that optionally write e.g. fuzz seeds into a directory
+    named in an environment valiable.
+    """
+    dir = os.environ.get(key)
+    if dir is None:
+        return None
+
+    if not os.path.isdir(dir):
+        raise ValueError(
+            f"{key} should name an existing directory (got '{dir}')")
+
+    return dir