Function teeForPhaseCapture

testing/e2e/src/routes/api.middleware-test.ts:158–166

* Wraps a chat stream so every chunk that leaves `chat()` (post-middleware) * is recorded into the per-testId phase capture as a yielded chunk. Used by * `phase-recorder` mode to let the spec assert what the consumer actually * sees — distinct from what `onChunk` observes inside the middleware ch

(
  source: AsyncIterable<StreamChunk>,
  captureId: string,
)

 * sees — distinct from what `onChunk` observes inside the middleware chain.
 */
async function* teeForPhaseCapture(
  source: AsyncIterable<StreamChunk>,
  captureId: string,
): AsyncIterable<StreamChunk> {
  for await (const chunk of source) {
    recordYieldedChunk(captureId, { type: chunk.type })
    yield chunk
  }
}

// Minimal in-memory tracer/meter. Captures into a per-testId bucket so that
// the Playwright spec can fetch the recorded state via GET after the stream