Fix empty components bug

nathanjmcdougall · nathanjmcdougall · commit 6dcf59c94ac0 · 2026-03-14T09:11:49.000+13:00
diff --git a/src/usethis/_pipeweld/func.py b/src/usethis/_pipeweld/func.py
@@ -506,6 +506,9 @@ def _get_instructions_for_insertion(
 
             endpoints.append(endpoint)
             instructions_per_sub.append(new_instructions)
+        if min_endpoint is None:
+            # If the existing components are empty...
+            min_endpoint = after
 
         for idx in range(len(component.root)):
             if idx != min_idx and instructions_per_sub[idx]:
diff --git a/tests/usethis/_integrations/ci/bitbucket/test_pipeweld.py b/tests/usethis/_integrations/ci/bitbucket/test_pipeweld.py
@@ -774,6 +774,22 @@ def test_empty_series_with_smaller_after(self):
             assert instructions == [InsertSuccessor(step="C", after="A")]
             assert endpoint == "C"
 
+        def test_all_empty_branches_preserves_after(self):
+            """When all branches are empty, no instructions are produced but the
+            endpoint should still be the original ``after`` value."""
+            # Arrange
+            component = parallel(series(), series())
+            after = "X"
+
+            # Act
+            instructions, endpoint = _get_instructions_for_insertion(
+                component, after=after
+            )
+
+            # Assert
+            assert instructions == []
+            assert endpoint == "X"
+
     class TestDepGroup:
         def test_basic(self):
             # Arrange
