fix(client): replace authorization headers case-insensitively

agentlightning/client.py

@@ -10,8 +10,8 @@
 import httpx
 
 
-def _headers_with_key(headers: httpx.Headers | dict[str, str] | None, key: str | None) -> dict[str, str]:
-    merged = dict(headers or {})
+def _headers_with_key(headers: httpx.Headers | dict[str, str] | None, key: str | None) -> httpx.Headers:
+    merged = httpx.Headers(headers)
     if key:
         merged["Authorization"] = f"Bearer {key}"
     return merged

tests/test_client.py

@@ -0,0 +1,58 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""Regression coverage for the clients' optional bearer key."""
+
+import httpx
+import pytest
+
+from agentlightning.client import AgentLightningAsyncClient, AgentLightningSyncClient
+
+
+@pytest.fixture(
+    params=[
+        {"Authorization": "Bearer old-test-key", "X-Custom": "preserved"},
+        {"authorization": "Bearer old-test-key", "X-Custom": "preserved"},
+        {"aUtHoRiZaTiOn": "Bearer old-test-key", "X-Custom": "preserved"},
+        httpx.Headers({"Authorization": "Bearer old-test-key", "X-Custom": "preserved"}),
+    ]
+)
+def headers(request: pytest.FixtureRequest) -> httpx.Headers | dict[str, str]:
+    return request.param.copy()
+
+
+def _assert_bearer(request: httpx.Request) -> httpx.Response:
+    assert request.headers.get_list("Authorization") == ["Bearer new-test-key"]
+    assert request.headers["X-Custom"] == "preserved"
+    return httpx.Response(200)
+
+
+def test_sync_key_replaces_authorization_case_insensitively(headers: httpx.Headers | dict[str, str]) -> None:
+    original = dict(headers)
+    with AgentLightningSyncClient(
+        headers=headers, key="new-test-key", max_retries=0, transport=httpx.MockTransport(_assert_bearer)
+    ) as client:
+        assert client.get("https://example.test").status_code == 200
+    assert dict(headers) == original
+
+
+@pytest.mark.asyncio
+async def test_async_key_replaces_authorization_case_insensitively(headers: httpx.Headers | dict[str, str]) -> None:
+    original = dict(headers)
+    async with AgentLightningAsyncClient(
+        headers=headers, key="new-test-key", transport=httpx.MockTransport(_assert_bearer)
+    ) as client:
+        assert (await client.get("https://example.test")).status_code == 200
+    assert dict(headers) == original
+
+
+@pytest.mark.parametrize("key", [None, ""])
+def test_sync_without_key_preserves_authorization(key: str | None) -> None:
+    with AgentLightningSyncClient(headers={"authorization": "Bearer old-test-key"}, key=key) as client:
+        assert client.headers.get_list("Authorization") == ["Bearer old-test-key"]
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("key", [None, ""])
+async def test_async_without_key_preserves_authorization(key: str | None) -> None:
+    async with AgentLightningAsyncClient(headers={"authorization": "Bearer old-test-key"}, key=key) as client:
+        assert client.headers.get_list("Authorization") == ["Bearer old-test-key"]