Explore creating robust HTTP services in Scala's functional programming paradigm. Gain insights into pure vs. impure implementations, their pros and cons, and effective tool usage.

scala-platform.tar.gz

Scala-Pure

Scala-Impure

Scala-Tapir

Scala-Impure-Test

Scala-Pure-Test

Scala-Tapir-Test

Test

Scala - Run Code Widget 

Scala-Pure-copy

Scala is one of the most popular general-purpose languages that supports both object-oriented and functional programming. In this course, you will learn how to create back-end HTTP services using Scala's functional programming paradigm.

You will also learn how to develop, test, and document the service using both pure and impure ways. You will be exposed to the differences between pure and impure implementation, their respective pros and cons, and how pure implementation can be more robust in terms of performance, understandability, testability, and type safeness. 

By the end of the course, you will have a clear idea of how functional programming works in Scala and how you can use the available tools more effectively.

Pure Functional HTTP APIs in Scala

# Configuration file for integration tests

First, we need to configure our test database because we do not want to accidentally wipe out our production database. For our case, we leave everything as is and change the database name. 





api {
    host = "localhost"
    port = 49152
}

database {
    profile = "slick.jdbc.PostgresProfile$"
    db {
        connectionPool = "HikariCP"
        dataSourceClass = "org.postgresql.ds.PGSimpleDataSource"
        properties {
            serverName = "localhost"
            portNumber = "5432"
            databaseName = "impure_test"
            user = "impure"
            password = "secret"
        }
        numThreads = 10
    }
} 

# Logging configuration for integration tests 

Another thing we should do is provide a test configuration for our logging framework. We use the *logback* library. *Slick* will produce a lot of logging output on the DEBUG level, so we should fix that. It is nice to have logging if you need it, but it also clutters up your log files. We create a file `logback-test.xml` in the directory `src/it/resources`, which should look like this: 


Learn how to set up integration tests by making a configuration file and implementing a base class.

Introduction

Impure Implementation

Pure Implementation

Testing Impure Services

Testing Pure Services

Benchmarks

Documentation

Epilogue

Setting Up Integration Tests

Configuration file for integration tests

Logging configuration for integration tests