Defining custom test functions

Weaver's IOSuite comes with a test function that provides logging, shared resource management and more. You can extend this by defining your own test functions.

Defining additional test functions

You can define additional test functions by calling registerTest.

For example, you can define a timedTest function to explicitly print the test duration to the log.

import weaver._
import cats.effect._

trait TimedSuite extends SimpleIOSuite {

  def timedTest(name: TestName)(run: IO[Expectations]): Unit =
    registerTest(name)(_ =>
      Test[IO](
        name.name,
        (log: Log[IO]) =>
          // Run the test, then log the time.
          for {
            (time, expectations) <- run.timed
            _                    <- log.info(s"Test took ${time.toSeconds} seconds")
          } yield expectations
      )
    )
}

The timedTest function behaves like any other test function.

import scala.concurrent.duration.*

object ExampleSuite extends TimedSuite {
  timedTest("timed test")(IO.sleep(2.seconds).as(failure("failed")))
}

Example report

ExampleSuite
- timed test 2s

*************FAILURES*************
ExampleSuite
- timed test 2s
  failed

  custom_test_functions.md#L38
    timedTest("timed test")(IO.sleep(2.seconds).as(failure("failed")))
                                                          ^

    [INFO] 12:32:01 [custom_test_functions.md:24] Test took 2 seconds

Total 1, Failed 1, Passed 0, Ignored 0

Redefining the test function

You cannot redefine weaver's test function, but you can define your own by extending SharedResourceSuite and implementing test.

For example, to time tests defined with your own test function:

import weaver._
import cats.effect._

trait TimedSuite extends SharedResourceSuite[IO] with BaseIOSuite with Expectations.Helpers {

  // Define the shared resource type
  type Res = Unit
  def sharedResource: Resource[IO, Unit] = Resource.pure[IO, Unit](())

  // Define the test function
  def test(name: TestName)(run: IO[Expectations]): Unit =
    registerTest(name)(_ =>
      Test[IO](
        name.name,
        (log: Log[IO]) =>
          for {
            (time, expectations) <- run.timed
            _                    <- log.info(s"Test took ${time.toSeconds} seconds")
          } yield expectations
      )
    )
}

This can be used in the same way as weaver's test function.

import scala.concurrent.duration._

object ExampleSuite extends TimedSuite {
  test("timed test")(IO.sleep(2.seconds).as(failure("failed")))
}

Example report

1ExampleSuite
- timed test 2s

*************FAILURES*************
1ExampleSuite
- timed test 2s
  failed

  custom_test_functions.md#L88
    test("timed test")(IO.sleep(2.seconds).as(failure("failed")))
                                                     ^

    [INFO] 12:32:03 [custom_test_functions.md:74] Test took 2 seconds

Total 1, Failed 1, Passed 0, Ignored 0