Function test_json_customization

tests/test_json.py:223–257

(app, client)

def test_json_customization(app, client):
    class X:  # noqa: B903, for Python2 compatibility
        def __init__(self, val):
            self.val = val

    def default(o):
        if isinstance(o, X):
            return f"<{o.val}>"

        return DefaultJSONProvider.default(o)

    class CustomProvider(DefaultJSONProvider):
        def object_hook(self, obj):
            if len(obj) == 1 and "_foo" in obj:
                return X(obj["_foo"])

            return obj

        def loads(self, s, **kwargs):
            kwargs.setdefault("object_hook", self.object_hook)
            return super().loads(s, **kwargs)

    app.json = CustomProvider(app)
    app.json.default = default

    @app.route("/", methods=["POST"])
    def index():
        return flask.json.dumps(flask.request.get_json()["x"])

    rv = client.post(
        "/",
        data=flask.json.dumps({"x": {"_foo": 42}}),
        content_type="application/json",
    )
    assert rv.data == b'"<42>"'


def _has_encoding(name):