Gap analysis — c8 in decision #427

scry-mcdc · library/core/src/slice/index.rs:272 · branch 2891

Status: GAP

What you need

To prove condition c8 independently affects the decision, you need a row where c8 = F and the outcome differs from row 17635 (where c8 = T).

Required condition vector:

  c0 = *
  c1 = *
  c2 = *
  c3 = *
  c4 = *
  c5 = F
  c6 = *
  c7 = *
  c8 = F
  c9 = *
  c10 = T
  c11 = *

Conditions marked * were short-circuited in the baseline row; the new test must drive inputs so they get evaluated to either T or F.

Suggested test stub

#[test]
fn closes_gap_d427_c8() {
    // Verdict: scry-mcdc
    // Source: library/core/src/slice/index.rs:272
    // Branch:  2891
    //
    // TODO: drive the function so condition c8 evaluates to the
    // value above and the resulting decision outcome differs from
    // the existing pair row.
    todo!("witness viz: gap drill-down for d#427/c8");
}

After adding the test, re-run: witness instrument && witness run --invoke run_row_NEW && witness report. The condition should flip from gap to proved.

← back to decision #427