to_compound: return an empty compound for an empty list instead of raising (#600) - #601
Open
youdie006 wants to merge 1 commit into
Open
to_compound: return an empty compound for an empty list instead of raising (#600)#601youdie006 wants to merge 1 commit into
youdie006 wants to merge 1 commit into
Conversation
Copy link
Copy Markdown
Sorry, something went wrong.
…ising to_compound() type-checked list inputs with isinstance(obj[0], ...) before handling the empty-list case, so to_compound([]) raised IndexError: list index out of range. This reached the object-tree render path (to_compound(node.obj).moved(...)) for an empty selection or intermediate result and crashed it. Handle an empty list explicitly, producing an empty compound (consistent with an empty Workplane). Add a regression test. Fixes CadQuery#600
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes #600.
Problem
to_compound() type-checks list inputs by indexing obj[0] before it handles the empty-list case:
So to_compound([]) raises IndexError: list index out of range. This is on a live render path: cq_editor/widgets/object_tree.py calls to_compound(node.obj).moved(world), so an empty selection or an empty intermediate result crashes the object-tree/assembly render.
Fix
Handle an empty list explicitly and return an empty compound, which is consistent with how an empty Workplane (whose vals() is empty) already flows through cq.Compound.makeCompound([]). I confirmed cq.Compound.makeCompound([]) returns an empty Compound rather than raising.
(The issue left the choice open between an empty compound and a raised error; empty compound keeps to_compound total over its declared input types and matches the empty-Workplane behavior. Happy to switch to a ValueError if you'd prefer.)
Test
Added test_to_compound_empty_list in tests/test_cq_utils.py. Red-green verified with pytest tests/test_cq_utils.py: before the change the test raises IndexError; after, to_compound([]) returns an empty cq.Compound. The existing test_cq_utils.py test still passes.
Disclosure: I used AI assistance (Claude) while preparing this change. I reproduced the crash, ran the tests (red-green), and take responsibility for the contribution.