| Element | Missed Instructions | Cov. | Missed Branches | Cov. | Missed | Cxty | Missed | Lines | Missed | Methods |
| Total | 49 of 200 | 76% | 10 of 22 | 55% | 8 | 20 | 7 | 36 | 1 | 9 |
| IOOutputStream(IRubyObject, Encoding, boolean, boolean) | | 65% | | 57% | 5 | 8 | 2 | 13 | 0 | 1 |
| close() | | 0% | | 0% | 3 | 3 | 5 | 5 | 1 | 1 |
| write(int) | | 100% | | 100% | 0 | 2 | 0 | 5 | 0 | 1 |
| write(byte[], int, int) | | 100% | | 100% | 0 | 2 | 0 | 4 | 0 | 1 |
| IOOutputStream(IRubyObject, boolean, boolean) | | 100% | n/a | 0 | 1 | 0 | 2 | 0 | 1 | |
| IOOutputStream(IRubyObject, Encoding) | | 100% | n/a | 0 | 1 | 0 | 2 | 0 | 1 | |
| write(byte[]) | | 100% | n/a | 0 | 1 | 0 | 2 | 0 | 1 | |
| IOOutputStream(IRubyObject) | | 100% | n/a | 0 | 1 | 0 | 2 | 0 | 1 | |
| static {...} | | 100% | n/a | 0 | 1 | 0 | 1 | 0 | 1 |