test: add tests for OpenRouter model info handling

tests/basic/test_openrouter.py

@@ -0,0 +1,76 @@
+import json
+from pathlib import Path
+
+import pytest
+
+from aider.openrouter import OpenRouterModelManager
+from aider.models import ModelInfoManager
+
+
+class DummyResponse:
+    """Minimal stand-in for requests.Response used in tests."""
+
+    def __init__(self, json_data):
+        self.status_code = 200
+        self._json_data = json_data
+
+    def json(self):
+        return self._json_data
+
+
+def test_openrouter_get_model_info_from_cache(monkeypatch, tmp_path):
+    """
+    OpenRouterModelManager should return correct metadata taken from the
+    downloaded (and locally cached) models JSON payload.
+    """
+    payload = {
+        "data": [
+            {
+                "id": "mistralai/mistral-medium-3",
+                "context_length": 32768,
+                "pricing": {"prompt": "100", "completion": "200"},
+                "top_provider": {"context_length": 32768},
+            }
+        ]
+    }
+
+    # Fake out the network call and the HOME directory used for the cache file
+    monkeypatch.setattr("requests.get", lambda *a, **k: DummyResponse(payload))
+    monkeypatch.setattr(Path, "home", staticmethod(lambda: tmp_path))
+
+    manager = OpenRouterModelManager()
+    info = manager.get_model_info("openrouter/mistralai/mistral-medium-3")
+
+    assert info["max_input_tokens"] == 32768
+    assert info["input_cost_per_token"] == 0.0001
+    assert info["output_cost_per_token"] == 0.0002
+    assert info["litellm_provider"] == "openrouter"
+
+
+def test_model_info_manager_uses_openrouter_manager(monkeypatch):
+    """
+    ModelInfoManager should delegate to OpenRouterModelManager when litellm
+    provides no data for an OpenRouter-prefixed model.
+    """
+    # Ensure litellm path returns no info so that fallback logic triggers
+    monkeypatch.setattr("aider.models.litellm.get_model_info", lambda *a, **k: {})
+
+    stub_info = {
+        "max_input_tokens": 512,
+        "max_tokens": 512,
+        "max_output_tokens": 512,
+        "input_cost_per_token": 0.0001,
+        "output_cost_per_token": 0.0002,
+        "litellm_provider": "openrouter",
+    }
+
+    # Force OpenRouterModelManager to return our stub info
+    monkeypatch.setattr(
+        "aider.models.OpenRouterModelManager.get_model_info",
+        lambda self, model: stub_info,
+    )
+
+    mim = ModelInfoManager()
+    info = mim.get_model_info("openrouter/fake/model")
+
+    assert info == stub_info