start()

in test-utils/mock-response.ts [35:46]


    start(controller) {
      while (currentChunkStart < input.length) {
        const substring = input.slice(
          currentChunkStart,
          currentChunkStart + chunkLength,
        );
        currentChunkStart += chunkLength;
        const chunk = encoder.encode(substring);
        controller.enqueue(chunk);
      }
      controller.close();
    },