Class CapturingPbWriter

showcase/harness/src/cvdiag/emit.test.ts:85–91

* A `CvdiagPbWriter` test double that captures every batch handed to * `writeBatch`. Resolves (never rejects), matching the best-effort seam * contract.

 * contract.
 */
class CapturingPbWriter implements CvdiagPbWriter {
  readonly batches: CvdiagEnvelope[][] = [];
  async writeBatch(events: CvdiagEnvelope[]): Promise<void> {
    // Capture a snapshot (callers may mutate/reuse arrays).
    this.batches.push([...events]);
  }
}

/** Emit N data-plane events that pass the default-tier filter. */
function emitN(emitter: CvdiagEmitter, n: number): void {