fix: reading *CONTROL_DEBUG (#643)

Co-authored-by: Mohamed Koubaa <[email protected]>
Co-authored-by: pyansys-ci-bot <[email protected]>

Author: 3 people

doc/changelog/643.fixed.md

@@ -0,0 +1 @@
+fix: reading *CONTROL_DEBUG

src/ansys/dyna/core/lib/field_writer.py

@@ -43,7 +43,8 @@ def _write_null(width):
 
 
 def _field_iterator(fields: typing.List[Field], long_format: bool) -> typing.Iterable[Field]:
-    assert len(fields) > 0, "at least one field is needed"
+    if len(fields) == 0:
+        return []
     if fields[0].offset > 0:
         # insert a blank field in the beginning up to the offset
         blank_field = Field(name=None, type=None, offset=0, width=fields[0].offset)

tests/test_deck.py

@@ -113,6 +113,14 @@ def test_deck_005():
     )
 
 
+@pytest.mark.keywords
+def test_control_debug():
+    from ansys.dyna.core.lib.deck import Deck
+    deck = Deck()
+    deck.loads('*CONTROL_DEBUG')
+    deck.write()
+
+
 @pytest.mark.keywords
 def test_deck_006(ref_string):
     """test adding two decks together"""