Error when using test_client (Flask) – raise ValueError(“unknown url type: %r” % self.full_url) [duplicate]

urllib.parse.quote("/" + str({"a": "b"}))
# '/%7B%27a%27%3A%20%27b%27%7D'

import pytest

from main import app


@pytest.fixture(scope="module")
def client():
    with app.test_client() as client:
        yield client


def test_flask_api_call(client):
    response = client.post("/", data={"a": "b"})
    assert response.status_code == 200, f"Got bad status code {response.status_code}"