PROJECT SETUP

• Requirements for the project: PHP, Git, Composer, Symfony binary (which can be downloaded from here: https://symfony.com/download)
• Clone the repository via Git
• Install all dependencies via composer
• Start the application with: symfony server:start

PROJECT DESIGN

• In order to easily accommodate for new sources, a chain of responsibility pattern is used to handle the request
• WeatherPrediction:getData() is the method that iterates through all the current source implementations
• All the Partner input sources implement the interface PartnerInputInterface
• Thanks to the configuration in config\services.yaml which is detailed below, services that implement the PartnerInputInterface are automatically tagged. That, in combination with the configuration for WeatherPrediction, any new source that implements the mentioned interface will be added into the flow automatically.

_instanceof:
        App\Client\PartnerInputInterface:
            tags: [ 'app.partner_weather_input' ]

App\Service\WeatherPrediction:
        arguments:
            - !tagged_iterator app.partner_weather_input

• The partner sources were mocked, as suggested in the assignment, and a cache layer was added for them
• Temperature scale conversion is done in TemperatureScaleConverter

ADDING A NEW SOURCE

• As mentioned in the PROJECT DESIGN section, any new source only needs to implement the interface PartnerInputInterface, and the data will be added into the existing flow

Notes

• Class diagram can be found in resources\class_diagram.puml
• PlantUML (https://plantuml.com/) is used to draw the diagram, an easy way to view it is through the PhpStorm plugin PlantUML integration
• Example endpoint to test the application: weather?city=Amsterdam&date=2021-10-06&scale=celsius
• Note that the only parameter that changes the response values for the predictions is scale due to the data being mocked
• The essential parts to cover with unit tests, if the target coverage would be 80%, are the elements that are part of the critical flow
  • Classes found in src\Service, src\Client and src\Factory, for example
  • This way we can ensure that the important components have the expected functionality