def test_environbuilder_json_dumps(app):
    """EnvironBuilder.json_dumps() takes settings from the app."""
    app.json.ensure_ascii = False
    eb = EnvironBuilder(app, json="\u20ac")
    assert eb.input_stream.read().decode("utf8") == '"\u20ac"'
EnvironBuilder.json_dumps() takes settings from the app.
tests/test_testing.py