add proxy test

tests/test_proxy.py

@@ -0,0 +1,20 @@
+import pytest
+from nonebug import App
+from nonebug.fixture import nonebug_init
+
+
+async def test_without_proxy(app: App):
+    from nonebot_bison.utils import http_client
+
+    c = http_client()
+    assert not c._mounts
+
+
+@pytest.mark.parametrize(
+    "nonebug_init", [{"bison_proxy": "http://example.com"}], indirect=True
+)
+async def test_with_proxy(app: App):
+    from nonebot_bison.utils import http_client
+
+    c = http_client()
+    assert c._mounts