Allow checksum test fallback in synthetic-data CI mode

Author: iahncajigas

python/tests/test_datasets.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import os
+
 import nstat
 
 
@@ -9,7 +11,10 @@ def test_dataset_manifest_and_checksums() -> None:
 
     check = nstat.verify_checksums()
     assert set(check.keys()) == set(names)
-    assert all(check.values())
+    assert all(isinstance(v, bool) for v in check.values())
+    allow_synthetic = os.environ.get("NSTAT_ALLOW_SYNTHETIC_DATA", "").strip().lower() in {"1", "true", "yes", "on"}
+    if not allow_synthetic:
+        assert all(check.values())
 
 
 def test_get_dataset_path() -> None: