Learn how to create, test, and compare the back-end HTTP services in Scala.

Become a Scala Developer

In this module, we will explore the functional aspects of Scala. We will start by looking at a small use case. We will then learn the difference between pure and impure implementations by looking into referential transparency and how functional programming relies on it. We will then gradually implement the use case in both pure and impure ways. Moving ahead, we will simultaneously build, test, and document the implementations and point out the tools required along the way. By the end of this module, we will have a substantial understanding of how these techniques work, their pros and cons, and how pure implementation can be more robust.

Pure Functional HTTP APIs in Scala

## What do we have left to test?

It seems the only parts left to test are the `FlywayDatabaseMigrator` and our `DoobieRepository` classes. Testing them will require a running database, so we leave the cozy world of unit tests behind and venture into integration test land. But fear not, we already have some — albeit impure — experience here.


## `BaseSpec` for pure integration tests
As usual, we start by implementing a base class that we can use to provide common settings and functions across our tests.




# What do we have left to test?

It seems the only parts left to test are the `FlywayDatabaseMigrator` and our `DoobieRepository` classes. Testing them will require a running database, so we leave the cozy world of unit tests behind and venture into integration test land. But fear not, we already have some — albeit impure — experience here.


# `BaseSpec` for pure integration tests
As usual, we start by implementing a base class that we can use to provide common settings and functions across our tests.




Learn how to set up integration tests for our pure service using a BaseSpec.

Introduction

Impure Implementation

Pure Implementation

Testing Impure Services

Testing Pure Services

Benchmarks

Documentation

Conclusion

Integration Tests Setup

What do we have left to test?