My Umbrella: Do I need an umbrella today?

An example application for the presentation:

Beyond Mocks - Messing with Our Preconceptions of Testing

This application demonstrates various tactics for testing external, unstable dependencies, AKA infrastructure. For the presentation, the focus is specifically on James Shore's technique, Nullables from the pattern language Testing Without Mocks.

Example

orlando = MyUmbrella.Coordinates.new(28.5383, -81.3792)
{:ok, weather} = MyUmbrella.for_today(orlando)
MyUmbrella.announce(weather)
#=> {:ok, MyUmbrella.Announcement{value: "Thunderstorms! Take two umbrellas!"}}

Sequence Diagram

sequenceDiagram
    Controller->>MyUmbrella: for_today(Coordinates.t())
    MyUmbrella->>WeatherApi: get_forecast(Coordinates.t(), :today)
    WeatherApi-->>MyUmbrella: {:ok, list(WeatherReport.t())}
    MyUmbrella->>WeatherReport: filter_by_same_day(list(WeatherReport.t()), DateTime.t())
    WeatherReport-->>MyUmbrella: list(WeatherReport.t())
    MyUmbrella->>Precipitation: determine_most_intense_precipitation_condition(list(WeatherReport.t()), :today)
    Precipitation-->>MyUmbrella: Precipitation.t()
    MyUmbrella-->>Controller: {:ok, Precipitation.t()}
    Controller->>MyUmbrella: announce(Precipitation.t())
    MyUmbrella->>Announcement: to_announcement(Precipitation.t())
    Announcement-->>MyUmbrella: Annoucement.t()
    MyUmbrella-->>Controller: Annoucement.t()

Loading

Development

Prerequites:

• asdf: https://asdf-vm.com/
• httpie: https://httpie.io/cli
• Open Weather Map Application ID: https://openweathermap.org/

Setup:

git clone https://github.com/nicholasjhenry/my_umbrella.git
cd ./my_umbrella
asdf install

Testing:

mix test

Lint and type checks:

mix check

Run:

# terminal window: 1
export OPEN_WEATHER_MAP_APP_ID=YOUR_APP_ID
mix server

# terminal window: 2
script/request