Adapter Design Pattern - Kotlin

AdapterDesignPattern.kt

class AdapterDesignPattern {
    companion object {
        @JvmStatic
        fun main(args: Array<String>) {
            println(CSVAdapterImpl(CSVFormatterImpl()).formatText("Hello. Romman Sabbir. How are you?."))
        }
    }
}

/**
 * Old interface from 3rd party vendor.
 */
interface TextFormatter {
    fun formatText(input: String): String
}

/**
 * Impl of old interface from 3rd party vendor.
 */
class TextFormatterImpl : TextFormatter {
    override fun formatText(input: String): String =
        input.replace(".", "\n")
}

/**
 * Our new interface that should work with old interface.
 */
interface CSVFormatter {
    fun formatText(input: String): String
}

/**
 * Impl of our new interface that should work with old interface.
 */
class CSVFormatterImpl : CSVFormatter {
    override fun formatText(input: String): String =
        input.replace(".", ",")
}

/**
 * Adapter that enable working new business logic with old interface [TextFormatter].
 * [CSVAdapterImpl] take an instance of [CSVFormatter] as a parameter in constructor.
 * We will execute our new logic by following the old interface.
 *
 * @param csvFormatter [CSVFormatter] instance.
 */
class CSVAdapterImpl constructor(private val csvFormatter: CSVFormatter) : TextFormatter {
    /**
     * We are calling [CSVFormatter] do our work according to our requirement instead of
     * following the old implementation from the external vendor.
     * 
     * @param input text that need to be formatted.
     * 
     * @return formatted output as [String]
     */
    override fun formatText(input: String): String = csvFormatter.formatText(input)
}