| Element | Missed Instructions | Cov. | Missed Branches | Cov. | Missed | Cxty | Missed | Lines | Missed | Methods |
| Total | 167 of 307 | 46% | 93 of 128 | 27% | 66 | 68 | 1 | 7 | 3 | 4 |
| unionAssignmentOperationToCeylon(Tree.UnionAssignOp, Callable) | | 50% | | 27% | 63 | 65 | 0 | 6 | 0 | 1 |
| unionAssignmentOperationToCeylon$update(Tree.UnionAssignOp) | | 0% | n/a | 1 | 1 | 1 | 1 | 1 | 1 | |
| unionAssignmentOperationToCeylon(Tree.UnionAssignOp) | | 0% | n/a | 1 | 1 | 1 | 1 | 1 | 1 | |
| unionAssignmentOperationToCeylon_() | | 0% | n/a | 1 | 1 | 0 | 0 | 1 | 1 |