Installation

Weaver-test is currently published for Scala 2.12, 2.13, and 3

SBT (1.9.0+)

Newer versions of SBT have weaver automatically integrated.

libraryDependencies +=  "org.typelevel" %% "weaver-cats" % "0.13.0" % Test

SBT (older versions)

Internally, SBT has a hardcoded list of test frameworks it integrates with. weaver must be manually added to this list.

libraryDependencies +=  "org.typelevel" %% "weaver-cats" % "0.13.0" % Test
testFrameworks += new TestFramework("weaver.framework.CatsEffect")

Mill

object test extends Tests {
  def ivyDeps = Agg(
    ivy"org.typelevel::weaver-cats:0.13.0"
  )
  def testFramework = "weaver.framework.CatsEffect"
}

scala-cli

//> using lib "org.typelevel::weaver-cats:0.13.0"
//> using testFramework "weaver.framework.CatsEffect" // this may be neccessary if you have other testFramework on your dependencies

Gradle

With Gradle plugin for multi-backend Scala:

plugins {
  id 'org.podval.tools.scalajs' version '<latest version>'
}
dependencies {
  testImplementation scalaBackend.testFramework(org.podval.tools.test.framework.WeaverTest)
}

Getting started

Start with importing the following :

import weaver._

The most basic usage is to extend SimpleIOSuite.

import cats.effect._

// Suites must be "objects" for them to be picked by the framework
object MySuite extends SimpleIOSuite {

  val randomUUID = IO(java.util.UUID.randomUUID())

  test("failing test with side-effects") {
    for {
      x <- randomUUID
      y <- randomUUID
    } yield expect.eql(x, y)
  }

  pureTest("pure failing test"){
    expect.eql("hello".size, 6)
  }

  loggedTest("failing test with logs"){ log =>
    for {
      x <- randomUUID
      _ <- log.info(s"x : $x")
      y <- randomUUID
      _ <- log.info(s"y : $y")
    } yield expect.eql(x, y)
  }
}

Run your tests with your build tool, e.g. sbt test.

MySuite
- failing test with side-effects 1ms
- pure failing test 0ms
- failing test with logs 3ms

*************FAILURES*************
MySuite
- failing test with side-effects 1ms
  Values not equal:

  in expect.eql(- expected, + found)
  -a4931642-bb07-4e16-bef2-0f2ecedc0ba7
  +57c3681d-6bfd-4752-a904-aa9af3622274

  installation.md#L25
      } yield expect.eql(x, y)
                        ^
- pure failing test 0ms
  Values not equal:

  in expect.eql(- expected, + found)
  -5
  +6

  installation.md#L29
      expect.eql("hello".size, 6)
                ^
- failing test with logs 3ms
  Values not equal:

  in expect.eql(- expected, + found)
  -0bb556b6-c1c3-4af3-adf0-bdf11d37c9be
  +37498158-06cd-498a-8198-40542b9cc47a

  installation.md#L38
      } yield expect.eql(x, y)
                        ^

    [INFO] 11:43:16 [installation.md:35] x : 0bb556b6-c1c3-4af3-adf0-bdf11d37c9be
    [INFO] 11:43:16 [installation.md:37] y : 37498158-06cd-498a-8198-40542b9cc47a

Total 3, Failed 3, Passed 0, Ignored 0

Other suites

Weaver also includes support for