How-to guides: developing

How to use a livereload development server

First, install hupper.

Then turn your Roll service into an importable module. Basically, a folder with and files and put your simple_server call within the file (see the examples/basic folder for… an example!).

Once you did that, you can run the server using hupper -m examples.basic. Each and every time you modify a python file, the server will reload and take into account your modifications accordingly.

One of the pros of using hupper is that you can even set an ipdb call within your code and it will work seamlessly (as opposed to using solutions like entr).

How to test forms

In case of the login form from the dedicated tutorial:

@app.route('/login', methods=['POST'])
async def login(request, response):
    username = request.form.get('username')
    password = request.form.get('password')
    response.body = f'Username: `{username}` password: `{password}`.'

Start to set the appropriated content type and then pass your data:

async def test_login_form(client):
    client.content_type = 'application/x-www-form-urlencoded'
    data = {'username': 'David', 'password': '123456'}
    resp = await'/test', data=data)
    assert resp.status == HTTPStatus.OK
    assert resp.body == b'Username: `David` password: `123456`.'

Note that you can send files too, for instance with an upload avatar view:

@app.route('/upload/avatar', methods=['POST'])
async def upload_avatar(req, resp):
    filename = req.files.get('avatar').filename
    content = req.files.get('avatar').read()
    resp.body = f'{filename} {content}'

Start to set the appropriated content type and then pass your files content:

async def test_avatar_form(client, app):
    client.content_type = 'multipart/form-data'
    files = {'avatar': (b'foo', 'me.png')}
    resp = await'/test', files=files)
    assert resp.status == HTTPStatus.OK
    assert resp.body == b'me.png foo'

How to run Roll’s tests

Roll exposes a pytest fixture (client), and for this needs to be properly installed so pytest sees it. Once in the roll root (and with your virtualenv active), run:

python develop

Then you can run the tests: