ai-agent-book 精选快照（<2MB 代码与文档，来自 github.com/bojieli/ai-agent-book）

chapter7/agent-cost-analysis/tests/conftest.py

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+"""Test import bootstrap for the agent-cost-analysis experiment."""
+
+from pathlib import Path
+import sys
+
+
+EXPERIMENT_ROOT = Path(__file__).resolve().parents[1]
+if str(EXPERIMENT_ROOT) not in sys.path:
+    sys.path.insert(0, str(EXPERIMENT_ROOT))

chapter7/agent-cost-analysis/tests/test_chat_null_usage.py

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+"""Tracer.chat must tolerate response.usage == None (OpenAI-compatible providers)."""
+
+from types import SimpleNamespace
+
+import config
+from tracer import Tracer
+
+
+class _FakeClient:
+    def __init__(self, usage):
+        self.chat = SimpleNamespace(
+            completions=SimpleNamespace(create=self._create)
+        )
+        self._usage = usage
+
+    def _create(self, **_kwargs):
+        return SimpleNamespace(usage=self._usage)
+
+
+def test_chat_tolerates_null_usage():
+    tr = Tracer(_FakeClient(None), pricing=config.default_pricing())
+    resp = tr.chat(step="turn-1", tool="query_order", model="m", messages=[])
+    assert resp.usage is None
+    assert len(tr.spans) == 1
+    s = tr.spans[0]
+    assert s.prompt_tokens == 0
+    assert s.completion_tokens == 0
+    assert s.cost_usd == 0.0
+    assert s.latency_s >= 0.0
+
+
+def test_chat_keeps_real_usage():
+    usage = SimpleNamespace(
+        prompt_tokens=100,
+        completion_tokens=20,
+        prompt_tokens_details=SimpleNamespace(cached_tokens=10),
+    )
+    tr = Tracer(_FakeClient(usage), pricing=config.default_pricing())
+    tr.chat(step="turn-1", tool="query_order", model="m", messages=[])
+    s = tr.spans[0]
+    assert s.prompt_tokens == 100
+    assert s.completion_tokens == 20
+    assert s.cached_tokens == 10
+    assert s.cost_usd > 0

chapter7/agent-cost-analysis/tests/test_trace_offline.py

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+"""
+Regression tests for offline trace parsing (实验 7-9 成本分析).
+
+Covers two crash classes found in --offline mode:
+  - Tracer.from_records: trace JSON with explicit null token fields -> int(None) TypeError
+  - demo.collect_offline: scenario dict missing the optional "spans" key -> KeyError
+"""
+import json
+
+import pytest
+
+import config
+import demo
+from tracer import Tracer
+
+
+def _span(**overrides):
+    span = {
+        "step": "turn-1",
+        "tool": "query_order",
+        "kind": "llm",
+        "prompt_tokens": 100,
+        "cached_tokens": 10,
+        "completion_tokens": 12,
+        "tool_ctx_tokens": 50,
+        "latency_s": 1.2,
+    }
+    span.update(overrides)
+    return span
+
+
+def test_from_records_tolerates_null_fields():
+    """Explicit JSON nulls in numeric fields are coerced, not int(None) TypeError."""
+    records = [_span(prompt_tokens=None, cached_tokens=None,
+                     completion_tokens=None, tool_ctx_tokens=None, latency_s=None)]
+    tr = Tracer.from_records(records, pricing=config.default_pricing())
+    s = tr.spans[0]
+    assert s.prompt_tokens == 0
+    assert s.cached_tokens == 0
+    assert s.completion_tokens == 0
+    assert s.tool_ctx_tokens == -1   # null tool_ctx 视为「未知」
+    assert s.latency_s == 0.0
+
+
+def test_from_records_tolerates_missing_fields():
+    """Minimal span dicts (only step/tool) still parse."""
+    tr = Tracer.from_records([{"step": "turn-1", "tool": "query_order"}],
+                             pricing=config.default_pricing())
+    assert tr.spans[0].prompt_tokens == 0
+    assert tr.spans[0].tool_ctx_tokens == -1
+
+
+def test_from_records_keeps_real_values():
+    """Normal values pass through unchanged (no coercion side effects)."""
+    tr = Tracer.from_records([_span()], pricing=config.default_pricing())
+    s = tr.spans[0]
+    assert (s.prompt_tokens, s.cached_tokens, s.completion_tokens) == (100, 10, 12)
+    assert s.tool_ctx_tokens == 50
+    assert s.latency_s == 1.2
+
+
+def test_from_records_keeps_zero_tool_ctx_tokens():
+    """Explicit 0 means known-zero tool context, not unknown (-1)."""
+    tr = Tracer.from_records([_span(tool_ctx_tokens=0)],
+                             pricing=config.default_pricing())
+    assert tr.spans[0].tool_ctx_tokens == 0
+    assert tr.total_tool_ctx_tokens() == 0
+
+
+def _write_trace(tmp_path, scenarios):
+    path = tmp_path / "trace.json"
+    path.write_text(json.dumps({"model": "gpt-5.6-luna", "scenarios": scenarios}),
+                    encoding="utf-8")
+    return str(path)
+
+
+def test_collect_offline_skips_scenario_without_spans(tmp_path, capsys):
+    """A scenario missing 'spans' is skipped with a warning, not a KeyError crash."""
+    trace = _write_trace(tmp_path, [
+        {"key": "naive", "name": "A naive"},                      # no spans -> skip
+        {"key": "both", "name": "B both", "spans": [_span()]},    # valid
+    ])
+    tracers = demo.collect_offline(["naive", "both"], config.default_pricing(), trace)
+    assert [k for k, _ in tracers] == ["both"]
+    assert "缺少 spans" in capsys.readouterr().err
+
+
+def test_collect_offline_exits_when_no_usable_scenario(tmp_path):
+    """When every selected scenario lacks spans, exit cleanly like the empty-trace path."""
+    trace = _write_trace(tmp_path, [{"key": "naive", "name": "A naive"}])
+    with pytest.raises(SystemExit):
+        demo.collect_offline(["naive"], config.default_pricing(), trace)
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])