Test: Add test for empty realm to fix coverage

tests/test_security_http_basic_empty_realm.py

@@ -0,0 +1,26 @@
+from fastapi import Depends, FastAPI, HTTPException
+from fastapi.security import HTTPBasic, HTTPBasicCredentials
+from fastapi.testclient import TestClient
+
+app = FastAPI()
+
+security = HTTPBasic(realm="")
+
+@app.get("/users/me")
+def read_current_user(credentials: HTTPBasicCredentials = Depends(security)):
+    return {"username": credentials.username, "password": credentials.password}
+
+client = TestClient(app)
+
+def test_security_http_basic_empty_realm():
+    response = client.get("/users/me", auth=("john", "secret"))
+    assert response.status_code == 200, response.text
+    assert response.json() == {"username": "john", "password": "secret"}
+
+def test_security_http_basic_invalid_credentials_empty_realm():
+    response = client.get(
+        "/users/me", headers={"Authorization": "Basic notabase64token"}
+    )
+    assert response.status_code == 401, response.text
+    assert response.headers["WWW-Authenticate"] == "Basic"
+    assert response.json() == {"detail": "Invalid authentication credentials"}