Clears the run accumulators in place for a re-run.

In place, not by replacement: concurrent group configs share the results object by reference (the group spread is shallow), so assigning a fresh results on one config would detach it from the others and split the run's totals across several objects. Assigning results.coverage is safe for the same reason — it mutates a field of the shared object rather than replacing it.

import * as RunState from './run-state.ts';

const { results } = RunState.create();
results.counter.failed = 3;
results.failedFiles.add('/proj/test/cart-test.ts');
RunState.reset(results, false);
[results.counter.failed, results.failedFiles.size]; // [0, 0] — same objects, cleared in place