Add tests for gemini via openai

tests/chat_model/test_openai_chat_model_gemini.py

@@ -0,0 +1,52 @@
+import os
+
+import pytest
+
+from magentic.chat_model.message import UserMessage
+from magentic.chat_model.openai_chat_model import OpenaiChatModel
+
+
+@pytest.mark.parametrize(
+    ("prompt", "output_types", "expected_output_type"),
+    [
+        ("Say hello!", [str], str),
+        ("Return True.", [bool], bool),
+        ("Return [1, 2, 3, 4, 5]", [list[int]], list),
+        ("Return a list of fruit", [list[str]], list),
+    ],
+)
+@pytest.mark.openai_gemini
+def test_openai_chat_model_complete_gemini(prompt, output_types, expected_output_type):
+    chat_model = OpenaiChatModel(
+        "gemini-1.5-flash",
+        api_key=os.environ["GEMINI_API_KEY"],
+        base_url="https://generativelanguage.googleapis.com/v1beta/openai/",
+    )
+    message = chat_model.complete(
+        messages=[UserMessage(prompt)], output_types=output_types
+    )
+    assert isinstance(message.content, expected_output_type)
+
+
+@pytest.mark.parametrize(
+    ("prompt", "output_types", "expected_output_type"),
+    [
+        ("Say hello!", [str], str),
+        ("Return True.", [bool], bool),
+        ("Return [1, 2, 3, 4, 5]", [list[int]], list),
+        ("Return a list of fruit", [list[str]], list),
+    ],
+)
+@pytest.mark.openai_gemini
+async def test_openai_chat_model_acomplete_gemini(
+    prompt, output_types, expected_output_type
+):
+    chat_model = OpenaiChatModel(
+        "gemini-1.5-flash",
+        api_key=os.environ["GEMINI_API_KEY"],
+        base_url="https://generativelanguage.googleapis.com/v1beta/openai/",
+    )
+    message = await chat_model.acomplete(
+        messages=[UserMessage(prompt)], output_types=output_types
+    )
+    assert isinstance(message.content, expected_output_type)