Assert object instance in scala FlatSpec - scala

Question

I am trying to create FlatSpec test that feels more like 'Scala' then 'Java'. Generally, I am interested how to assert an instance of class File.
Here is what I have:
File.scala
package org.demo.entries
class File(
val parentPath: String,
val name: String,
val contents: String)
AssertEntries.scala
package org.demo.entries
import org.scalatest.{FlatSpec, Matchers}
object AssertEntries extends FlatSpec with Matchers{
def assertFileEntry(expectedParentPath: String,
expectedName: String,
expectedContent: String,
actual: File) = {
actual should have (
'name (expectedName),
'parentPath (expectedParentPath),
'contents (expectedContent)
)
}
}
FileTest.scala
package org.demo.entries
import org.scalatest.{FlatSpec, Matchers}
import org.demo.entries.AssertEntries._
class FileTest extends FlatSpec with Matchers {
val PATH1: String = "unrelated"
val NAME1: String = "somename"
val CONTENT1: String = "somecontent"
"A file" should "be created" in {
val actual : File = new File(PATH1, NAME1, CONTENT1)
assertFileEntry(PATH1, NAME1, CONTENT1, actual) // Is there some better approach?
}
}
As you can see, I am using my own assertFileEntry method to assert the instance of the file. Generally, this approach is more like Java, but considering that Scala has different syntax, I was wondering, is there a different approach that looks more like Scala?
Copying contents of assertFileEntry every time I want to check an instance of File, seems not so convenient.
Updated background:
For the clarity, I have omitted the rest of the code. Generally File class is extending DirEntry class which has two subtypes: File and Directory. Directory have additional list that contains DirEntries.
I want to test if given Directory contains created files (and nested directories) by iterating through list of parent Directory and calling assertFileEntry (or assertDirectoryEntry) and assert each entry with expected values.
That is the reason why I created assertFileEntry method, to do all the assertions for given File instance there, but, at least to me, my solution seems more like a Java then Scala solution

Answer 1

Your approach seems fine enough if it works. I would personally create assertFileEntry as a private method inside FileTest if it's used nowhere else, and construct the tests like this:
package org.demo.entries
import org.scalatest.{FlatSpec, Matchers}
class FileSpec extends FlatSpec with Matchers {
val PATH1: String = "unrelated"
val NAME1: String = "somename"
val CONTENT1: String = "somecontent"
private def assertFileEntry(expectedParentPath: String,
expectedName: String,
expectedContent: String,
actual: File) = {
actual.name shouldBe expectedName
actual.contents shouldBe expectedContent
actual.parentPath shouldBe expectedParentPath
}
"A file" should "be created" in {
val actual: File = new File(PATH1, NAME1, CONTENT1)
assertFileEntry(PATH1, NAME1, CONTENT1, actual)
}
}
There are countless ways to do what you want in Scala though so just pick a method which works for you. It might be better to assert individual things in separate tests though if your tests get more complicated than this, so it's easier to locate which part of your code is failing.
Also, in Scala it's more conventional to name the test files like {class name}Spec rather than {class name}Test, for example FileSpec or ControllerSpec over FileTest or ControllerTest.