feat(pilot): emit per-review Langfuse traces

Ship token spend, latency and equivalent cost for every review to the self-hosted Langfuse so per-model behaviour is queryable as a trend rather than one PR comment at a time. langfuse_trace.py is stdlib-only and emits via the public ingestion API. Traces split into `ollama` and `claude` environments keyed off the bare model name, not the provider: both paths go through the same headroom proxy, so the provider prefix says nothing about which spend story a review belongs to. The pilot's own path bills $0, so the reported cost is the equivalent price from cost_model.PRICES. ai_review.py calls _emit_langfuse on both token-spending exit paths (the normal post and the salvage path). Import and emission are wrapped in a blanket except: with no LANGFUSE_HOST or key pair the whole thing is a silent no-op, and a telemetry failure must never fail a review. These files were previously deployed only by way of the image build's `COPY . /app`, so a clean checkout would have silently dropped tracing. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-31 12:45:35 +00:00
parent 51b81def98
commit 92283c44e8
5 changed files with 789 additions and 0 deletions
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+"""Unit tests for Langfuse trace emission. No network.
+
+`_post` is monkeypatched everywhere a POST would happen; a test that reaches
+the real network is a bug in the test, not a slow test.
+"""
+import json
+import os
+import sys
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+ROOT = os.path.abspath(os.path.join(HERE, "..", ".."))
+sys.path.insert(0, os.path.join(ROOT, "pilot"))
+
+import langfuse_trace as lt  # noqa: E402
+
+
+USAGE = {
+    "input": 2_000_000,
+    "output": 17_000,
+    "reasoning": 500,
+    "cache_read": 400_000,
+    "cache_write": 50_000,
+    "total": 2_017_000,
+    "cost": 0.0,
+    "steps": 28,
+    "duration_s": 348.3,
+}
+
+BASE = dict(
+    repo="techspark/pragent",
+    index="42",
+    sha="2613b3e1122334455",
+    title="Harden the review path",
+    usage=USAGE,
+    findings=[
+        {"severity": "critical", "path": "a.py"},
+        {"severity": "minor", "path": "b.py"},
+        {"severity": "minor", "path": "c.py"},
+    ],
+    summary="Three findings.",
+)
+
+
+# ---------------------------------------------------------------------------
+# model -> environment split (the whole point of the integration)
+# ---------------------------------------------------------------------------
+
+
+def test_claude_models_land_in_the_claude_environment():
+    assert lt.resolve_environment("headroom/claude-sonnet-5") == "claude"
+    assert lt.resolve_environment("claude-opus-5") == "claude"
+
+
+def test_everything_else_lands_in_the_ollama_environment():
+    for m in (
+        "headroom/glm-5.2:cloud",
+        "headroom/MiniMax-M2.7",
+        "vllm-qwen38/qwen3.8-27b",
+        "gpt-5",
+    ):
+        assert lt.resolve_environment(m) == "ollama", m
+
+
+def test_provider_and_bare_model_are_split_on_the_first_slash_only():
+    assert lt.provider_of("vllm-qwen38/qwen3.8-27b") == "vllm-qwen38"
+    assert lt.strip_provider("headroom/glm-5.2:cloud") == "glm-5.2:cloud"
+    # A bare name has no provider prefix; default to the pilot's proxy.
+    assert lt.provider_of("glm-5.2:cloud") == "headroom"
+    assert lt.strip_provider("glm-5.2:cloud") == "glm-5.2:cloud"
+
+
+# ---------------------------------------------------------------------------
+# usage accounting
+# ---------------------------------------------------------------------------
+
+
+def test_cache_reads_are_subtracted_from_input_not_added():
+    # Langfuse sums usageDetails keys; opencode reports cache_read *inside*
+    # input, so reporting both raw would bill the prefix twice.
+    d = lt._usage_details(USAGE)
+    assert d["input"] == 2_000_000 - 400_000
+    assert d["cache_read_input_tokens"] == 400_000
+    assert d["cache_write_input_tokens"] == 50_000
+    assert d["output"] == 17_000
+    assert d["reasoning"] == 500
+
+
+def test_zero_cache_fields_are_omitted_rather_than_sent_as_zero():
+    d = lt._usage_details({"input": 100, "output": 10})
+    assert d == {"input": 100, "output": 10}
+
+
+def test_a_paid_model_is_priced_as_itself():
+    costs, basis = lt._cost_details(USAGE, "headroom/claude-sonnet-5")
+    assert costs["total"] > 0
+    assert basis == "actual"
+
+
+def test_minimax_is_priced_against_the_comparison_target_not_zero():
+    # MiniMax-M2.7 is the model the webhook actually runs and it is absent from
+    # PRICES; charting it at $0 would make the whole dashboard a flat line.
+    costs, basis = lt._cost_details(USAGE, "headroom/MiniMax-M2.7")
+    assert costs["total"] > 0
+    assert basis == "equivalent:claude-sonnet-5"
+
+
+def test_glm_is_priced_against_the_comparison_target():
+    costs, basis = lt._cost_details(USAGE, "headroom/glm-5.2:cloud")
+    assert costs["total"] > 0
+    assert basis.startswith("equivalent:")
+
+
+def test_an_all_zero_price_entry_counts_as_free_not_as_priced():
+    # The self-hosted vLLM qwen IS in PRICES, at 0.00 across the board.
+    costs, basis = lt._cost_details(USAGE, "vllm-qwen38/qwen3.8-27b")
+    assert costs["total"] > 0
+    assert basis.startswith("equivalent:")
+
+
+def test_explicit_price_target_wins_over_the_default():
+    costs, basis = lt._cost_details(USAGE, "headroom/MiniMax-M2.7", "claude-opus-5")
+    assert basis == "equivalent:claude-opus-5"
+    sonnet, _ = lt._cost_details(USAGE, "headroom/MiniMax-M2.7", "claude-sonnet-5")
+    assert costs["total"] > sonnet["total"]
+
+
+def test_env_overrides_the_default_target(monkeypatch):
+    monkeypatch.setenv("PRAGENT_PRICE_TARGET", "claude-haiku-4-5")
+    assert lt.resolve_price_target() == "claude-haiku-4-5"
+    # An explicit argument still beats the env.
+    assert lt.resolve_price_target("gpt-5") == "gpt-5"
+
+
+def test_unknown_comparison_target_yields_no_cost_block_rather_than_a_wrong_one():
+    costs, basis = lt._cost_details(USAGE, "headroom/MiniMax-M2.7", "not-a-real-model")
+    assert costs == {}
+    assert basis == ""
+
+
+# ---------------------------------------------------------------------------
+# batch shape
+# ---------------------------------------------------------------------------
+
+
+def test_batch_has_a_trace_and_a_generation_linked_by_trace_id():
+    batch = lt.build_batch(model="headroom/claude-sonnet-5", **BASE)
+    types = [e["type"] for e in batch]
+    assert types == ["trace-create", "generation-create"]
+    trace, gen = batch
+    assert gen["body"]["traceId"] == trace["body"]["id"]
+    assert trace["body"]["environment"] == gen["body"]["environment"] == "claude"
+
+
+def test_batch_without_usage_is_trace_only():
+    batch = lt.build_batch(model="headroom/glm-5.2:cloud", **{**BASE, "usage": None})
+    assert [e["type"] for e in batch] == ["trace-create"]
+
+
+def test_trace_carries_repo_pr_session_and_severity_counts():
+    batch = lt.build_batch(model="headroom/glm-5.2:cloud", **BASE)
+    body = batch[0]["body"]
+    assert body["sessionId"] == "techspark/pragent#42"
+    assert body["metadata"]["severities"] == {"critical": 1, "minor": 2}
+    assert body["metadata"]["findings"] == 3
+    assert "provider:headroom" in body["tags"]
+    assert "model:glm-5.2:cloud" in body["tags"]
+
+
+def test_lens_names_become_tags():
+    batch = lt.build_batch(
+        model="headroom/glm-5.2:cloud", lenses=["security", "tests"], **BASE
+    )
+    assert "lens:security" in batch[0]["body"]["tags"]
+    assert "lens:tests" in batch[0]["body"]["tags"]
+
+
+def test_cost_basis_is_tagged_so_equivalent_is_never_read_as_spend():
+    batch = lt.build_batch(model="headroom/MiniMax-M2.7", **BASE)
+    trace = batch[0]["body"]
+    assert "cost:equivalent:claude-sonnet-5" in trace["tags"]
+    assert trace["metadata"]["cost_basis"] == "equivalent:claude-sonnet-5"
+
+    paid = lt.build_batch(model="headroom/claude-sonnet-5", **BASE)
+    assert "cost:actual" in paid[0]["body"]["tags"]
+
+
+def test_minimax_generation_carries_a_nonzero_cost():
+    batch = lt.build_batch(model="headroom/MiniMax-M2.7", **BASE)
+    assert batch[1]["body"]["costDetails"]["total"] > 0
+
+
+def test_batch_is_json_serializable():
+    batch = lt.build_batch(model="headroom/claude-sonnet-5", **BASE)
+    json.dumps({"batch": batch})
+
+
+# ---------------------------------------------------------------------------
+# emit_review_trace — config gate and fail-open
+# ---------------------------------------------------------------------------
+
+
+def _configure(monkeypatch):
+    monkeypatch.setenv("LANGFUSE_HOST", "http://langfuse.test:3000/")
+    monkeypatch.setenv("LANGFUSE_PUBLIC_KEY", "pk-lf-test")
+    monkeypatch.setenv("LANGFUSE_SECRET_KEY", "sk-lf-test")
+
+
+def test_no_config_means_no_post_and_no_error(monkeypatch):
+    for k in ("LANGFUSE_HOST", "LANGFUSE_PUBLIC_KEY", "LANGFUSE_SECRET_KEY"):
+        monkeypatch.delenv(k, raising=False)
+    calls = []
+    monkeypatch.setattr(lt, "_post", lambda *a, **k: calls.append(a) or 200)
+    assert lt.emit_review_trace(model="headroom/glm-5.2:cloud", **BASE) is False
+    assert calls == []
+
+
+def test_configured_emit_posts_to_the_ingestion_endpoint(monkeypatch):
+    _configure(monkeypatch)
+    seen = {}
+
+    def fake_post(host, pk, sk, batch, timeout):
+        seen.update(host=host, pk=pk, sk=sk, batch=batch, timeout=timeout)
+        return 207
+
+    monkeypatch.setattr(lt, "_post", fake_post)
+    assert lt.emit_review_trace(model="headroom/claude-sonnet-5", **BASE) is True
+    # Trailing slash stripped so the path is not doubled.
+    assert seen["host"] == "http://langfuse.test:3000"
+    assert len(seen["batch"]) == 2
+
+
+def test_transport_failure_is_swallowed(monkeypatch):
+    _configure(monkeypatch)
+
+    def boom(*a, **k):
+        raise OSError("connection refused")
+
+    monkeypatch.setattr(lt, "_post", boom)
+    assert lt.emit_review_trace(model="headroom/glm-5.2:cloud", **BASE) is False
+
+
+def test_non_success_status_reports_failure_without_raising(monkeypatch):
+    _configure(monkeypatch)
+    monkeypatch.setattr(lt, "_post", lambda *a, **k: 401)
+    assert lt.emit_review_trace(model="headroom/glm-5.2:cloud", **BASE) is False