Function parseSSEStream

packages/ai/tests/stream-to-response.test.ts:483–517

* Helper to parse SSE stream back into chunks

(
    sseStream: ReadableStream<Uint8Array>,
  )

   * Helper to parse SSE stream back into chunks
   */
  async function parseSSEStream(
    sseStream: ReadableStream<Uint8Array>,
  ): Promise<Array<Record<string, unknown>>> {
    const reader = sseStream.getReader()
    const decoder = new TextDecoder()
    const chunks: Array<Record<string, unknown>> = []
    let buffer = ''

    try {
      while (true) {
        const { done, value } = await reader.read()
        if (done) break

        buffer += decoder.decode(value, { stream: true })
        const lines = buffer.split('\n\n')
        buffer = lines.pop() || ''

        for (const line of lines) {
          if (line.startsWith('data: ')) {
            const data = line.slice(6)
            if (data === '[DONE]') continue
            try {
              chunks.push(JSON.parse(data))
            } catch {
              // Skip invalid JSON
            }
          }
        }
      }
    } finally {
      reader.releaseLock()
    }

    return chunks
  }

  it('should preserve TEXT_MESSAGE_CONTENT events', async () => {
    const originalChunks: Array<Record<string, unknown>> = [