Function empty_vertices_produce_auto_merge

atomic-core/src/merge/engine.rs:631–657

()

    #[test]
    fn empty_vertices_produce_auto_merge() {
        let mut txn = MockTxn::new();
        let store = MemoryChangeStore::new();

        // All three are empty content (structural inodes).
        let hash = make_change(&store, b"");
        let id = NodeId::new(1);
        txn.register(id, hash);

        let engine = SemanticMergeEngine::new(&txn, &store);

        // Empty vertices: start == end.
        let v1 = GraphNode::new(id, ChangePosition::new(0), ChangePosition::new(0));
        let v2 = GraphNode::new(id, ChangePosition::new(0), ChangePosition::new(0));
        let ancestor = GraphNode::new(id, ChangePosition::new(0), ChangePosition::new(0));

        let group = ConflictGroup::new(vec![v1, v2]).with_ancestor(ancestor);
        let outcome = engine.try_merge(&group).unwrap();

        // Empty tokens on all sides → trivially merged.
        assert!(
            outcome.is_auto_merged(),
            "expected AutoMerged for empty, got {:?}",
            outcome
        );
        assert!(outcome.content().is_empty());
    }

    // ---- SemanticMergeEngine: exposes references ---------------------------