Implement-LLM-WP-0005-cost-model-estimators

tests/test_rates.py

@@ -0,0 +1,65 @@
+import pytest
+
+from llm_connect.rates import ModelRate, ModelRateRegistry
+
+
+def test_default_registry_contains_openrouter_seed_models():
+    registry = ModelRateRegistry.default()
+    rates = registry.all()
+
+    assert len(rates) >= 9
+    assert rates["openai/gpt-4o-mini"].captured_at == "2026-05-17"
+    assert rates["openai/gpt-4o-mini"].source_url == "https://openrouter.ai/models"
+
+
+def test_from_yaml_loads_package_shape(tmp_path):
+    path = tmp_path / "model-rates.yaml"
+    path.write_text(
+        """
+schema_version: 1
+currency: USD
+source_url: https://example.test/rates
+captured_at: "2026-05-19"
+rates:
+  vendor/model:
+    prompt_per_1k: 0.1
+    completion_per_1k: 0.2
+""",
+        encoding="utf-8",
+    )
+
+    registry = ModelRateRegistry.from_yaml(path)
+    rate = registry.get("vendor/model")
+
+    assert rate == ModelRate(
+        model_id="vendor/model",
+        prompt_per_1k=0.1,
+        completion_per_1k=0.2,
+        currency="USD",
+        source_url="https://example.test/rates",
+        captured_at="2026-05-19",
+    )
+
+
+def test_merged_with_overrides_matching_model():
+    base = ModelRateRegistry.default()
+    override = ModelRateRegistry(
+        {
+            "openai/gpt-4o-mini": ModelRate(
+                "openai/gpt-4o-mini",
+                prompt_per_1k=1,
+                completion_per_1k=2,
+                captured_at="override",
+            )
+        }
+    )
+
+    merged = base.merged_with(override)
+
+    assert merged.get("openai/gpt-4o-mini").prompt_per_1k == 1
+    assert merged.get("openai/gpt-4o-mini").captured_at == "override"
+
+
+def test_negative_rates_are_rejected():
+    with pytest.raises(ValueError, match="prompt_per_1k"):
+        ModelRate("bad/model", prompt_per_1k=-1, completion_per_1k=0)