Testing Flask-JSONRPC Applications

Testing is critical for JSON-RPC services. Flask-JSONRPC integrates seamlessly with Flask’s built-in test client.

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Using Flask’s Test Client

import unittest
from app import create_app

class RPCAppTestCase(unittest.TestCase):
    def setUp(self):
        self.app = create_app()
        self.client = self.app.test_client()

    def rpc_call(self, method, params=None, id=1):
        data = {
            "jsonrpc": "2.0",
            "method": method,
            "id": id
        }
        if params is not None:
            data["params"] = params
        response = self.client.post("/api", json=data)
        return response.get_json()

    def test_ping(self):
        result = self.rpc_call("ping")
        self.assertEqual(result["result"], "pong")

    def test_add(self):
        result = self.rpc_call("math.add", [3, 4])
        self.assertEqual(result["result"], 7)

if __name__ == "__main__":
    unittest.main()

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Batch Requests Testing

You can also test batch requests:

def test_batch(self):
    batch_data = [
        {"jsonrpc": "2.0", "method": "ping", "id": 1},
        {"jsonrpc": "2.0", "method": "math.add", "params": [1, 2], "id": 2}
    ]
    response = self.client.post("/api", json=batch_data)
    results = response.get_json()
    self.assertEqual(results[0]["result"], "pong")
    self.assertEqual(results[1]["result"], 3)

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Mocking Dependencies

Use standard Python mocking techniques to replace dependencies:

from unittest.mock import patch

@patch("app.db_query")
def test_user_query(mock_db):
    mock_db.return_value = {"name": "Alice"}
    result = rpc_call("user.get", {"id": 1})
    assert result["result"]["name"] == "Alice"