Added tests for passing multiple codes or exceptons to `exception_handler`

tests/test_exception_handlers.py

@@ -5,6 +5,14 @@ from fastapi.testclient import TestClient
 from starlette.responses import JSONResponse
 
 
+class CustomException1(HTTPException):
+    pass
+
+
+class CustomException2(HTTPException):
+    pass
+
+
 def http_exception_handler(request, exception):
     return JSONResponse({"exception": "http-exception"})
 
@@ -86,3 +94,62 @@ def test_traceback_for_dependency_with_yield():
     last_frame = exc_info.traceback[-1]
     assert str(last_frame.path) == __file__
     assert last_frame.lineno == raise_value_error.__code__.co_firstlineno
+
+
+def test_exception_handler_with_single_exception():
+    local_app = FastAPI()
+
+    @local_app.exception_handler(CustomException1)
+    def custom_exception_handler(request, exception):
+        pass  # pragma: no cover
+
+    assert (
+        local_app.exception_handlers.get(CustomException1) == custom_exception_handler
+    )
+
+
+@pytest.mark.parametrize(
+    "exceptions",
+    [
+        (CustomException1, CustomException2),  # Tuple of exceptions
+        [CustomException1, CustomException2],  # List of exceptions
+    ],
+)
+def test_exception_handler_with_multiple_exceptions(exceptions):
+    local_app = FastAPI()
+
+    @local_app.exception_handler(exceptions)
+    def custom_exception_handler(request, exception):
+        pass  # pragma: no cover
+
+    assert local_app.exception_handlers.get(exceptions[0]) == custom_exception_handler
+
+    assert local_app.exception_handlers.get(exceptions[1]) == custom_exception_handler
+
+
+def test_exception_handler_with_single_status_code():
+    local_app = FastAPI()
+
+    @local_app.exception_handler(409)
+    def http_409_status_code_handler(request, exception):
+        pass  # pragma: no cover
+
+    assert local_app.exception_handlers.get(409) == http_409_status_code_handler
+
+
+@pytest.mark.parametrize(
+    "status_codes",
+    [
+        (401, 403),  # Tuple of status codes
+        [401, 403],  # List of status codes
+    ],
+)
+def test_exception_handler_with_multiple_status_codes(status_codes):
+    local_app = FastAPI()
+
+    @local_app.exception_handler(status_codes)
+    def auth_errors_handler(request, exception):
+        pass  # pragma: no cover
+
+    assert local_app.exception_handlers.get(status_codes[0]) == auth_errors_handler
+    assert local_app.exception_handlers.get(status_codes[1]) == auth_errors_handler