Hands-On Software Engineering with Golang

The services behind the facade

Before we dive deeper into the inner workings of the price calculator, let's spend a bit of time examining how the two microservice dependencies work; after all, we will need this information to write our tests.

The price microservice provides a REST endpoint for retrieving an item's published price on a particular date. The service responds with a JSON payload that looks like this:

{
    "price": 10.0,
    "currency": "GBP"
}

The second microservice in this example is called vat and is also RESTful. It exposes an endpoint for retrieving the VAT rate that was applicable on a particular date. The service responds with a JSON payload as follows:

{
    "vat_rate": 0.29
}

As you can see, the returned JSON payload is quite ...