metona-ai-desktop/electron/harness/adapters/__tests__/sse-stream.test.ts

/**
 * SSE 流式解析器单元测试（v0.4.1 测试补齐）
 * 覆盖：TEXT_DELTA / REASONING_DELTA / TOOL_CALL 增量拼接 / USAGE /
 *       [DONE] / finish_reason=tool_calls 提前 flush / 坏 JSON 行容错 / 损坏工具调用跳过
 */

import { describe, it, expect, vi, afterEach } from 'vitest';
import {
  parseSSEStream,
  parseOpenAICompatibleResponse,
  readStreamChunkWithIdleTimeout,
  SseUpstreamError,
} from '../shared/sse-stream';
import { MetonaStreamEventType } from '../../types';

/** 构造 SSE 测试流 */
function makeStream(chunks: string[]): ReadableStream<Uint8Array> {
  const encoder = new TextEncoder();
  return new ReadableStream<Uint8Array>({
    start(controller) {
      for (const c of chunks) controller.enqueue(encoder.encode(c));
      controller.close();
    },
  });
}

async function collect(
  stream: ReadableStream<Uint8Array>,
): Promise<Array<{ type: string; [k: string]: unknown }>> {
  const events: Array<{ type: string; [k: string]: unknown }> = [];
  for await (const ev of parseSSEStream(stream, 'req_test', 'sess_test', 1)) {
    events.push(ev as unknown as { type: string; [k: string]: unknown });
  }
  return events;
}

describe('parseSSEStream — 文本与推理增量', () => {
  it('TEXT_DELTA 事件按序产出', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"content":"你好"}}]}\n\n',
        'data: {"choices":[{"delta":{"content":"，世界"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const deltas = events.filter((e) => e.type === MetonaStreamEventType.TEXT_DELTA);
    expect(deltas).toHaveLength(2);
    expect(deltas[0].delta).toBe('你好');
    expect(deltas[1].delta).toBe('，世界');
    expect(events[events.length - 1].type).toBe(MetonaStreamEventType.DONE);
  });

  it('REASONING_DELTA（Thinking 模式）事件产出', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"reasoning_content":"让我想想"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const reasoning = events.find((e) => e.type === MetonaStreamEventType.REASONING_DELTA);
    expect(reasoning?.delta).toBe('让我想想');
  });

  it('同一个 chunk 中 content 和 reasoning_content 同时产出', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"content":"答","reasoning_content":"思考"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    expect(events.filter((e) => e.type === MetonaStreamEventType.TEXT_DELTA)).toHaveLength(1);
    expect(events.filter((e) => e.type === MetonaStreamEventType.REASONING_DELTA)).toHaveLength(1);
  });
});

describe('parseSSEStream — 工具调用增量拼接', () => {
  it('分段 arguments 拼接为完整 JSON 并在 finish_reason=tool_calls 时 flush', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"name":"read_file","arguments":"{\\"pa"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"arguments":"th\\": \\"a.ts\\"}"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{},"finish_reason":"tool_calls"}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const completes = events.filter((e) => e.type === MetonaStreamEventType.TOOL_CALL_COMPLETE);
    expect(completes).toHaveLength(1);
    const tc = completes[0].toolCall as { name: string; args: Record<string, unknown> };
    expect(tc.name).toBe('read_file');
    expect(tc.args).toEqual({ path: 'a.ts' });
  });

  it('多个工具调用按 index 分别拼接', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"name":"tool_a","arguments":"{}"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{"tool_calls":[{"index":1,"function":{"name":"tool_b","arguments":"{}"}}]}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const completes = events.filter((e) => e.type === MetonaStreamEventType.TOOL_CALL_COMPLETE);
    expect(completes).toHaveLength(2);
    const names = completes.map((e) => (e.toolCall as { name: string }).name);
    expect(names).toEqual(['tool_a', 'tool_b']);
  });

  it('损坏的 args JSON 转为截断错误 tool call 回传模型（不丢弃、不中断流）', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"name":"bad_tool","arguments":"{invalid json"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{"content":"后续文本"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    // v0.6.3 契约: 坏 JSON 的工具调用不再静默丢弃（丢弃会让引擎误判 COMPLETED
    // 空回复终止会话）— 转为携带 _truncatedArguments 错误说明的 tool call，
    // 工具执行失败后错误结果回传模型触发自愈
    const completes = events.filter((e) => e.type === MetonaStreamEventType.TOOL_CALL_COMPLETE);
    expect(completes).toHaveLength(1);
    const tc = completes[0].toolCall as { name: string; args: Record<string, unknown> };
    expect(tc.name).toBe('bad_tool');
    expect(tc.args._truncatedArguments).toBe(true);
    // 流继续处理后续事件
    expect(events.some((e) => e.type === MetonaStreamEventType.TEXT_DELTA)).toBe(true);
    expect(events[events.length - 1].type).toBe(MetonaStreamEventType.DONE);
  });
});

describe('parseSSEStream — USAGE 与容错', () => {
  it('USAGE 事件解析 DeepSeek 缓存字段', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[],"usage":{"prompt_tokens":100,"completion_tokens":50,"total_tokens":150,"prompt_cache_hit_tokens":80,"prompt_cache_miss_tokens":20}}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const usageEvent = events.find((e) => e.type === MetonaStreamEventType.USAGE);
    const usage = usageEvent?.usage as Record<string, number>;
    expect(usage.inputTokens).toBe(100);
    expect(usage.outputTokens).toBe(50);
    expect(usage.totalTokens).toBe(150);
    expect(usage.cacheHitTokens).toBe(80);
    expect(usage.cacheMissTokens).toBe(20);
  });

  it('坏 JSON 行不中断后续事件（记录警告后继续）', async () => {
    const events = await collect(
      makeStream([
        'data: {broken json\n\n',
        'data: {"choices":[{"delta":{"content":"ok"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    expect(events.some((e) => e.type === MetonaStreamEventType.TEXT_DELTA)).toBe(true);
    expect(events[events.length - 1].type).toBe(MetonaStreamEventType.DONE);
  });

  it('跨 chunk 分割的 SSE 行正确拼接', async () => {
    // "data: {...}\n\n" 被切到两个网络 chunk 中
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"cont',
        'ent":"拼接成功"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const delta = events.find((e) => e.type === MetonaStreamEventType.TEXT_DELTA);
    expect(delta?.delta).toBe('拼接成功');
  });

  it('空行与非 data 行被忽略', async () => {
    const events = await collect(
      makeStream([
        ': comment line\n\n',
        '\n',
        'data: {"choices":[{"delta":{"content":"x"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    expect(events.filter((e) => e.type === MetonaStreamEventType.TEXT_DELTA)).toHaveLength(1);
  });
});

describe('parseOpenAICompatibleResponse — 非流式响应', () => {
  it('解析普通文本响应', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [{ message: { content: 'hello' }, finish_reason: 'stop' }],
      usage: { prompt_tokens: 10, completion_tokens: 5, total_tokens: 15 },
    });
    expect(result.content).toBe('hello');
    expect(result.finishReason).toBe('stop');
    expect(result.usage.inputTokens).toBe(10);
    expect(result.toolCalls).toBeUndefined();
  });

  it('解析 reasoning_content（Thinking 模式）', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [
        { message: { content: 'answer', reasoning_content: 'thinking...' }, finish_reason: 'stop' },
      ],
      usage: {},
    });
    expect(result.reasoningContent).toBe('thinking...');
  });

  it('解析 tool_calls（字符串 arguments 反序列化）', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [
        {
          message: {
            content: null,
            tool_calls: [{ id: 'tc_1', function: { name: 'run', arguments: '{"cmd":"ls"}' } }],
          },
          finish_reason: 'tool_calls',
        },
      ],
      usage: {},
    });
    expect(result.toolCalls).toHaveLength(1);
    expect(result.toolCalls![0].name).toBe('run');
    expect(result.toolCalls![0].args).toEqual({ cmd: 'ls' });
  });

  it('损坏的 tool_calls arguments 转为 _truncatedArguments 自愈载荷（v0.6.4: 不再静默降级 {}）', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [
        {
          message: {
            content: null,
            tool_calls: [{ id: 'tc_1', function: { name: 'run', arguments: '{bad' } }],
          },
          finish_reason: 'tool_calls',
        },
      ],
      usage: {},
    });
    const args = result.toolCalls![0].args as Record<string, unknown>;
    expect(args._truncatedArguments).toBe(true);
    expect(String(args._truncatedReason)).toContain('truncated');
  });

  it('mapOpenAIFinishReason 覆盖 MiMo repetition_truncation', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [{ message: { content: 'x' }, finish_reason: 'repetition_truncation' }],
      usage: {},
    });
    expect(result.finishReason).toBe('stop');
  });
});

// ===== v0.7.4 P1-2: 流空闲超时 =====

describe('parseSSEStream — 流空闲超时（P1-2）', () => {
  it('连续无数据超过空闲阈值时抛 SseUpstreamError(504)', async () => {
    const { readStreamChunkWithIdleTimeout } = await import('../shared/sse-stream');

    // 构造一个永不返回数据的 reader（挂死流）
    const neverReader = {
      read: () => new Promise<{ done: boolean; value?: Uint8Array }>(() => {}),
      releaseLock: () => {},
      cancel: () => Promise.resolve(),
      closed: Promise.resolve(),
    } as unknown as ReadableStreamDefaultReader<Uint8Array>;

    // 使用共享辅助函数直接验证：空闲超时抛 SseUpstreamError(504)
    await expect(readStreamChunkWithIdleTimeout(neverReader, 50)).rejects.toMatchObject({
      status: 504,
    });

    // 数据到达时重置空闲窗口（不抛错）
    const delayedReader = {
      read: () =>
        new Promise<{ done: boolean; value?: Uint8Array }>((resolve) => {
          setTimeout(() => resolve({ done: true, value: undefined }), 10);
        }),
      releaseLock: () => {},
      cancel: () => Promise.resolve(),
      closed: Promise.resolve(),
    } as unknown as ReadableStreamDefaultReader<Uint8Array>;
    const result = await readStreamChunkWithIdleTimeout(delayedReader, 200);
    expect(result.done).toBe(true);
  });
});

// ===== 追加：readStreamChunkWithIdleTimeout 专项 =====

describe('readStreamChunkWithIdleTimeout — 空闲超时语义', () => {
  afterEach(() => {
    vi.restoreAllMocks();
    vi.useRealTimers();
  });

  function makeReader(
    reads: Array<{ delay: number; value?: string; done?: boolean }>,
  ): ReadableStreamDefaultReader<Uint8Array> {
    const encoder = new TextEncoder();
    let i = 0;
    return {
      read: () =>
        new Promise<{ done: boolean; value?: Uint8Array }>((resolve) => {
          const spec = reads[Math.min(i, reads.length - 1)];
          i++;
          setTimeout(() => {
            if (spec.done) resolve({ done: true, value: undefined });
            else
              resolve({ done: false, value: spec.value ? encoder.encode(spec.value) : undefined });
          }, spec.delay);
        }),
      releaseLock: () => {},
      cancel: () => Promise.resolve(),
      closed: Promise.resolve(),
    } as unknown as ReadableStreamDefaultReader<Uint8Array>;
  }

  it('空闲超时抛 SseUpstreamError(504)，消息含 idle timeout', async () => {
    const reader = makeReader([{ delay: 10_000 }]);
    const promise = readStreamChunkWithIdleTimeout(reader, 30);
    await expect(promise).rejects.toMatchObject({
      name: 'SseUpstreamError',
      status: 504,
      message: expect.stringContaining('idle timeout'),
    });
  });

  it('数据在超时前到达 → 正常返回数据（空闲窗口被重置）', async () => {
    const reader = makeReader([
      { delay: 5, value: 'data: {}' },
      { done: true, delay: 1 },
    ]);
    const first = await readStreamChunkWithIdleTimeout(reader, 100);
    expect(first.done).toBe(false);
    expect(new TextDecoder().decode(first.value)).toBe('data: {}');
    const second = await readStreamChunkWithIdleTimeout(reader, 100);
    expect(second.done).toBe(true);
  });

  it('连续多次 read 均未超时（每次数据到达重置计时器）', async () => {
    const reader = makeReader([
      { delay: 5, value: 'a' },
      { delay: 5, value: 'b' },
      { done: true, delay: 5 },
    ]);
    for (const expectValue of ['a', 'b']) {
      const r = await readStreamChunkWithIdleTimeout(reader, 50);
      expect(new TextDecoder().decode(r.value)).toBe(expectValue);
    }
    const last = await readStreamChunkWithIdleTimeout(reader, 50);
    expect(last.done).toBe(true);
  });

  it('超时后 timer 被清理（fake timers 验证无遗留定时器）', async () => {
    vi.useFakeTimers();
    const reader = {
      read: () => new Promise<{ done: boolean; value?: Uint8Array }>(() => {}),
      releaseLock: () => {},
      cancel: () => Promise.resolve(),
      closed: Promise.resolve(),
    } as unknown as ReadableStreamDefaultReader<Uint8Array>;
    const promise = readStreamChunkWithIdleTimeout(reader, 100);
    // 先挂上 rejection 处理器，再推进计时器，避免 unhandledRejection 竞态
    const assertion = expect(promise).rejects.toMatchObject({ status: 504 });
    await vi.advanceTimersByTimeAsync(150);
    await assertion;
    // finally 清理后不应有残留 timer
    expect(vi.getTimerCount()).toBe(0);
  });

  it('数据到达正常结束后 timer 同样被清理', async () => {
    vi.useFakeTimers();
    const encoder = new TextEncoder();
    const reader = {
      read: vi.fn(
        () =>
          Promise.resolve({ done: true, value: undefined }) as Promise<{
            done: boolean;
            value?: Uint8Array;
          }>,
      ),
      releaseLock: () => {},
      cancel: () => Promise.resolve(),
      closed: Promise.resolve(),
    } as unknown as ReadableStreamDefaultReader<Uint8Array>;
    const r = await readStreamChunkWithIdleTimeout(reader, 100);
    expect(r.done).toBe(true);
    expect(vi.getTimerCount()).toBe(0);
    void encoder;
  });
});

// ===== 追加：parseSSEStream 更多解析细节 =====

describe('parseSSEStream — 帧格式兼容扩展', () => {
  it('CRLF 行结束符（\\r\\n）正常解析', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"content":"crlf"}}]}\r\n\r\n',
        'data: [DONE]\r\n\r\n',
      ]),
    );
    expect(
      events.some((e) => e.type === MetonaStreamEventType.TEXT_DELTA && e.delta === 'crlf'),
    ).toBe(true);
    expect(events[events.length - 1].type).toBe(MetonaStreamEventType.DONE);
  });

  it('同一 chunk 内连续多个 SSE 事件均被处理', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"content":"一"}}]}\n\n' +
          'data: {"choices":[{"delta":{"content":"二"}}]}\n\n' +
          'data: [DONE]\n\n',
      ]),
    );
    const deltas = events.filter((e) => e.type === MetonaStreamEventType.TEXT_DELTA);
    expect(deltas.map((e) => e.delta)).toEqual(['一', '二']);
  });

  it('一个 SSE 行被切成 4 个网络 chunk 仍能拼接', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"del',
        'ta":{"content":"跨',
        'chunk拼接成功',
        '"}}]}\n\ndata: [DONE]\n\n',
      ]),
    );
    const delta = events.find((e) => e.type === MetonaStreamEventType.TEXT_DELTA);
    expect(delta?.delta).toBe('跨chunk拼接成功');
  });

  it('data: 后无空格且无内容的空 data 行被忽略', async () => {
    const events = await collect(
      makeStream([
        'data:\n\n',
        'data: {"choices":[{"delta":{"content":"x"}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    expect(events.filter((e) => e.type === MetonaStreamEventType.TEXT_DELTA)).toHaveLength(1);
  });

  it('choices 存在但 delta 为空对象 → 不产生事件（静默帧）', async () => {
    const events = await collect(
      makeStream(['data: {"choices":[{"delta":{}}]}\n\n', 'data: [DONE]\n\n']),
    );
    expect(events.filter((e) => e.type === MetonaStreamEventType.TEXT_DELTA)).toHaveLength(0);
    expect(events[events.length - 1].type).toBe(MetonaStreamEventType.DONE);
  });

  it('工具调用：arguments 被切成 5 段拼接为合法 JSON', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"name":"f","arguments":"{\\"a\\":"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"arguments":"1,"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"arguments":"\\"b\\":"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"arguments":"[1,2]}"}}]}}]}\n\n',
        'data: {"choices":[{"delta":{},"finish_reason":"tool_calls"}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const completes = events.filter((e) => e.type === MetonaStreamEventType.TOOL_CALL_COMPLETE);
    expect(completes).toHaveLength(1);
    expect((completes[0].toolCall as { args: Record<string, unknown> }).args).toEqual({
      a: 1,
      b: [1, 2],
    });
  });

  it('工具调用 arguments 为空 → 完成时 args 为 {}（无参工具合法）', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"name":"noop"}}]}}]}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const completes = events.filter((e) => e.type === MetonaStreamEventType.TOOL_CALL_COMPLETE);
    expect(completes).toHaveLength(1);
    expect((completes[0].toolCall as { args: Record<string, unknown> }).args).toEqual({});
  });

  it('流断开（无 [DONE]）时 flush 缓冲工具调用 + 补发 DONE', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"name":"last_tool","arguments":"{\\"ok\\":true}"}}]}}]}\n\n',
      ]),
    );
    const completes = events.filter((e) => e.type === MetonaStreamEventType.TOOL_CALL_COMPLETE);
    expect(completes).toHaveLength(1);
    expect(events[events.length - 1].type).toBe(MetonaStreamEventType.DONE);
  });
});

// ===== 追加：USAGE 扩展字段 =====

describe('parseSSEStream — USAGE 扩展字段', () => {
  it('MiMo prompt_tokens_details.cached_tokens 映射 cacheHitTokens', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[],"usage":{"prompt_tokens":10,"completion_tokens":5,"total_tokens":15,"prompt_tokens_details":{"cached_tokens":7}}}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const usage = events.find((e) => e.type === MetonaStreamEventType.USAGE)?.usage as Record<
      string,
      unknown
    >;
    expect(usage.cacheHitTokens).toBe(7);
    expect(usage.cacheMissTokens).toBeUndefined();
  });

  it('DeepSeek reasoning_tokens 映射 reasoningTokens', async () => {
    const events = await collect(
      makeStream([
        'data: {"choices":[],"usage":{"prompt_tokens":1,"completion_tokens":1,"total_tokens":2,"completion_tokens_details":{"reasoning_tokens":99}}}\n\n',
        'data: [DONE]\n\n',
      ]),
    );
    const usage = events.find((e) => e.type === MetonaStreamEventType.USAGE)?.usage as Record<
      string,
      unknown
    >;
    expect(usage.reasoningTokens).toBe(99);
  });

  it('无 usage 字段的数据帧不产生 USAGE 事件', async () => {
    const events = await collect(
      makeStream(['data: {"choices":[{"delta":{"content":"x"}}]}\n\n', 'data: [DONE]\n\n']),
    );
    expect(events.some((e) => e.type === MetonaStreamEventType.USAGE)).toBe(false);
  });
});

// ===== 追加：上游错误帧 status 推断矩阵 =====

describe('parseSSEStream — 上游错误帧 status 推断矩阵', () => {
  async function collectError(json: unknown): Promise<Error> {
    const stream = makeStream([`data: ${JSON.stringify(json)}\n\n`]);
    try {
      for await (const _ev of parseSSEStream(stream, 'r', 's', 1)) void _ev;
    } catch (err) {
      return err as Error;
    }
    throw new Error('expected throw');
  }

  it.each([
    [{ error: { code: 'rate_limit_exceeded', message: 'rl' } }, 429],
    [{ error: { code: 'too_many_requests', message: 'rl' } }, 429],
    [{ error: { code: 'insufficient_quota', message: 'q' } }, 402],
    [{ error: { code: 'billing_error', message: 'q' } }, 402],
    [{ error: { code: 'exceeded_balance', message: 'q' } }, 402],
    [{ error: { code: 'invalid_api_key', message: 'auth' } }, 401],
    [{ error: { code: 'authentication_error', message: 'auth' } }, 401],
    [{ error: { code: 'forbidden', message: 'deny' } }, 403],
    [{ error: { code: 'permission_denied', message: 'deny' } }, 403],
    [{ error: { code: 'model_not_found', message: 'no model' } }, 404],
    [{ error: { code: 'overloaded', message: 'busy' } }, 503],
    [{ error: { code: 'capacity_exceeded', message: 'busy' } }, 503],
    [{ error: { code: 'server_error', message: '500' } }, 500],
    [{ error: { code: 'internal_error', message: '500' } }, 500],
  ] as const)('providerCode %s → status %d', async (errorObj, expectedStatus) => {
    const err = await collectError(errorObj);
    expect(err).toBeInstanceOf(SseUpstreamError);
    expect((err as SseUpstreamError).status).toBe(expectedStatus);
  });

  it('无效参数类 code（无匹配规则）→ status undefined（非重试语义）', async () => {
    const err = await collectError({
      error: { code: 'invalid_request_error', message: 'bad param' },
    });
    expect(err).toBeInstanceOf(SseUpstreamError);
    expect((err as SseUpstreamError).status).toBeUndefined();
    expect((err as SseUpstreamError).providerCode).toBe('invalid_request_error');
  });

  it('status_code 数字字段被识别（非 status 命名）', async () => {
    const err = await collectError({
      error: { message: 'gateway timeout', status_code: 504 },
    });
    expect((err as SseUpstreamError).status).toBe(504);
  });

  it('msg 字段作为错误消息（非 message 命名）', async () => {
    const err = await collectError({ error: { msg: 'custom msg', code: 'overloaded' } });
    expect((err as Error).message).toContain('custom msg');
    expect((err as SseUpstreamError).status).toBe(503);
  });

  it('error 为空对象 → 回退 message 为 {}（JSON.stringify 兜底使其仍被识别为错误帧）', async () => {
    // 源码注明的防御意图是无害空对象不报错，但 message 兜底取 JSON.stringify({})='{}'，
    // 恒真值使该防御分支失效 —— 此处锁定实际行为并留档（见报告）。
    const err = await collectError({ error: {} });
    expect(err).toBeInstanceOf(SseUpstreamError);
    expect((err as Error).message).toContain('upstream_error');
    expect((err as SseUpstreamError).status).toBeUndefined();
  });

  it('error 为空白字符串 → 不算错误帧', async () => {
    const events: string[] = [];
    for await (const ev of parseSSEStream(
      makeStream(['data: {"error":"   "}\n\n', 'data: [DONE]\n\n']),
      'r',
      's',
      1,
    )) {
      events.push(ev.type);
    }
    expect(events[events.length - 1]).toBe(MetonaStreamEventType.DONE);
  });
});

// ===== 追加：parseOpenAICompatibleResponse 更多形态 =====

describe('parseOpenAICompatibleResponse — 补充形态', () => {
  it('空 choices 数组 → content 空字符串 + finishReason stop + 无 toolCalls', () => {
    const result = parseOpenAICompatibleResponse({ choices: [], usage: {} });
    expect(result.content).toBe('');
    expect(result.finishReason).toBe('stop');
    expect(result.toolCalls).toBeUndefined();
  });

  it('无 message 的 choice → 安全回退', () => {
    const result = parseOpenAICompatibleResponse({ choices: [{ finish_reason: 'stop' }] });
    expect(result.content).toBe('');
    expect(result.reasoningContent).toBeUndefined();
  });

  it('usage 缺失 → 全 0 token', () => {
    const result = parseOpenAICompatibleResponse({ choices: [{ message: { content: 'x' } }] });
    expect(result.usage).toEqual({ inputTokens: 0, outputTokens: 0, totalTokens: 0 });
  });

  it('usage cache 双格式回退（DeepSeek 命中 + MiMo cached_tokens）', () => {
    const ds = parseOpenAICompatibleResponse({
      choices: [{ message: { content: 'x' } }],
      usage: { prompt_cache_hit_tokens: 5, prompt_cache_miss_tokens: 6 },
    });
    expect(ds.usage.cacheHitTokens).toBe(5);
    expect(ds.usage.cacheMissTokens).toBe(6);

    const mimo = parseOpenAICompatibleResponse({
      choices: [{ message: { content: 'x' } }],
      usage: { prompt_tokens_details: { cached_tokens: 9 } },
    });
    expect(mimo.usage.cacheHitTokens).toBe(9);
  });

  it('arguments 为空字符串 → JSON.parse 失败走截断自愈载荷（与坏参同轨）', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [
        {
          message: { tool_calls: [{ id: 'c', function: { name: 'f', arguments: '' } }] },
          finish_reason: 'tool_calls',
        },
      ],
    });
    expect((result.toolCalls![0].args as Record<string, unknown>)._truncatedArguments).toBe(true);
  });

  it('arguments 为对象类型 → 原样保留（不解析）', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [
        {
          message: { tool_calls: [{ id: 'c', function: { name: 'f', arguments: { a: 1 } } }] },
          finish_reason: 'tool_calls',
        },
      ],
    });
    expect(result.toolCalls![0].args).toEqual({ a: 1 });
  });

  it('reasoning_tokens 透传到 usage.reasoningTokens', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [{ message: { content: 'x' } }],
      usage: { completion_tokens_details: { reasoning_tokens: 42 } },
    });
    expect(result.usage.reasoningTokens).toBe(42);
  });

  it('tool_calls 元素缺 id → id undefined 不抛错', () => {
    const result = parseOpenAICompatibleResponse({
      choices: [
        {
          message: { tool_calls: [{ function: { name: 'f', arguments: '{}' } }] },
          finish_reason: 'tool_calls',
        },
      ],
    });
    expect(result.toolCalls).toHaveLength(1);
    expect(result.toolCalls![0].id).toBeUndefined();
  });
});