Bug validate about flask-jsonrpc

[nycholas]

Hi,

This is a huge bug on validation, we will fix it.

Thank you.

[nycholas]

Hi,

One detail, the return of method can't be known before the evaluation. The code bellow will work on validate, but will break on execution:

@jsonrpc.method('add(a=int, b=int)')
def add(a: int, b: int):
    ...
    return 0

The test:

def test_app_create_with_method_without_annotation_on_return():
    app = Flask(__name__, instance_relative_config=True)
    jsonrpc = JSONRPC(app, '/api', enable_web_browsable_api=True)

    # pylint: disable=W0612
    @jsonrpc.method('app.fn1')
    def fn1(s: str):
        return 'Foo {0}'.format(s)

    # pylint: disable=W0612
    @jsonrpc.method('app.fn2')
    def fn2(s: str) -> str:
        return 'Bar {0}'.format(s)

    with app.test_client() as client:
        rv = client.post('/api', json={'id': 1, 'jsonrpc': '2.0', 'method': 'app.fn1', 'params': [':)']})
        assert rv.json == {
            'error': {
                'code': -32602,
                'data': {
                    'message': 'return type of str must be a type; got NoneType instead'
                },
                'message': 'Invalid params',
                'name': 'InvalidParamsError',
            },
            'id': 1,
            'jsonrpc': '2.0',
        }
        assert rv.status_code == 400

        rv = client.post('/api', json={'id': 1, 'jsonrpc': '2.0', 'method': 'app.fn2', 'params': [':)']})
        assert rv.json == {'id': 1, 'jsonrpc': '2.0', 'result': 'Bar :)'}
        assert rv.status_code == 200

Thank you.