Kata: Sing a song (refactoring)

You can find a Node.js and JavaScript ES6 implementation of the kata in the javascript folder; produce the song with:

node song.js

Similarly a Ruby version can be found in the ruby folder; produce the song with:

ruby song.rb

A Python version can be found in the python folder; produce the song with:

python song.py

A Java version can be found in the java folder; produce the song with:

javac Song.java && java Song

A Kotlin version can be found in the kotlin folder; produce the song with:

 kotlinc Song.kt -include-runtime -d Song.jar 
 java -jar Song.jar

A PHP version can be found in the PHP folder; produce the song with:

php song.php

A .NET Core version implementation of the kata in the csharp\dotnetcore folder; produce the song with:

cd song
dotnet run

A Go version can be found in the golang folder; produce the song with:

go run main.go

You can find out more about the London Code Dojo at our homepage.

Objective

Code to produce a popular children's nursary rhyme was produced by a web agency for the customer last year. The customer now desires to produce multiple different versions of the song using the same structure but based on different themes, for example a current popular children's movie featuring a cast of animals. The customer asks that you make the song configurable for different lists of animals. The customer cannot guarentee that there will be the same number of animals in each different version.

No documentation or tests were provided by the previous developer.

Refactor the code to allow for the customer's needs. Remember: refactoring can only be done in the presence of tests that are passing, and after refactoring the tests still pass!

License

The code samples are licensed under the CC-SA-NC-4.0 license, as shown in the LICENSE file.