scalatet 中的 assertEquals

Question

I'd like to use something similar to jUnit's assertEquals in scalatest.

Does the framework implement it or it does just provide assert and I should use assertEquals from jUnit itself?

Answer 1

There's the 'assert' approach such as

class EqualsTest extends FunSuite {
  test("equals") {
    assert(1 === 1)
    assert(2 === 2, "The reason is obvious")
  }
}

Note the use of triple-equals, which gives much better error messages than double-equals when the test fails. Also, the second case provides a hint to be printed if the test fails. It's best to use this for including some data value that would not otherwise be obvious, eg a loop count if testing using a loop.

Then there's the ShouldMatchers approach such as

class EqualsTest extends FunSuite with ShouldMatchers {
  test("equals") {
    1 should be (1)
  }
}

This is often preferred because it reads easily. However, learning to use it is just a bit harder - there are some nooks and crannies in the API. And you can't put in a hint explanation.

Answer 2

One of the great things about ScalaTest is that it doesn't force you to do things its way - it allows you to choose the approach that fits best with your particular situation and preferences. As well as the approaches in the other answers you've already received, there's also (and my personal preference):

class EqualsTest extends FunSuite {
  test("equals") {
    expectResult(1) { 1 }
  }
}

(note that expectResult is expect in ScalaTest 1.x).

Answer 3

assert(Actual.equals(Expected))