has_collection did `collection_name in self.client.list_collections()`,
but chromadb's list_collections() returns Collection objects (1.x), not
name strings — so the membership test is always False, even when the
collection exists. Compare against the collection names instead (with a
hasattr guard tolerating versions that yield plain names).
Found via the dependency-contract test suite (unit/deps/test_chromadb.py).
Classic298
15d96b1f2a