Intent

Manually fail or succeed a test

Two convenience methods exists where you can manually provide the the test expectation:

• fail("Reason for failure...") to fail a test
• success() to pass a test

Asyncness

If you need to await the result of a Future before using a matcher, you can use whenComplete:

whenComplete(Future.successful(Seq("foo", "bar"))):
  actual => expect(actual).toContain("foo")

This allows for more complex testing compared to when using toCompleteWith.

whenComplete can be used regardless of the suite type, i.e. it doesn’t need to be in an AsyncState suite. The async part of AsyncState allows for building the test state asynchronously, but has nothing to do with the expectations used.

Equality

It is possible to define custom equality for a type. Consider the following example from Intent’s own test suite:

given customIntEq as intent.core.Eq[Int] :
  def areEqual(a: Int, b: Int) = Math.abs(a - b) == 1
expect(Some(42)).toEqual(Some(43))

In this case, a custom equality definition for Int says that two values are equal if they diff by 1. This causes the toEqual matcher to succeed.

Floating-point precision

When floating-point values (Float and Double) are compared, Intent compares up to a certain precision, defined as the number of decimals that must match.

Here’s an example where a custom precision is used:

given customPrecision as intent.core.FloatingPointPrecision[Float] :
  def numberOfDecimals: Int = 2
expect(1.234f).toEqual(1.235f)

The test passes because we say that two Floats are equal to the precision of 2 decimals. In other words, the equality check actually compares 1.23 and 1.23.

The default precision is 12 decimals for Double and 6 decimals for Float.

Formatting

It is possible to customize how a value is printed in a test failure message. Here’s an example from Intent’s test suite that shows how:

given customIntFmt as core.Formatter[Int] :
  def format(a: Int): String = a.toString.replace("4", "forty-")
runExpectation(expect(42).toEqual(43),
  "Expected forty-3 but found forty-2")

Timeout

The default timeout for whenComplete and toCompleteWith is 5 seconds. It is possible to use a custom timeout:

given customTimeout as TestTimeout = TestTimeout(500.millis)
expect(someFuture).toCompleteWith("fast")