What's the right way to use scala.io.Source?

Question

In many examples, it is described that you can use scala.io.Source to read a whole file like this:

val str = scala.io.Source.fromFile("test.txt").mkString() 

But closing the underlying stream is not mentioned.

Why does Scala not provide a convenient way to do that such as with clause in Python? It looks useful but not difficult.

Is there any other better way to do that safely in Scala, I means to read a whole file?

Answer 1

Starting Scala 2.13, the standard library provides a dedicated resource management utility: Using.

It can be used in this case with scala.io.Source as it extends AutoCloseable in order to read from a file and, no matter what, close the file resource afterwards:

import scala.util.Using import scala.io.Source  Using(Source.fromFile("file.txt")) { source => source.mkString } // scala.util.Try[String] = Success("hello\nworld\n")