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 7ms
- pure failing test 5ms
- failing test with logs 8ms

*************FAILURES*************
MySuite
- failing test with side-effects 7ms
  Values not equal:

  in expect.eql(- expected, + found)
  -39bb7a3d-f2d0-4c85-aa99-9d01292aa0f3
  +9b8f47fc-1012-4b17-b367-4417b5a1d976

  installation.md#L25
      } yield expect.eql(x, y)
                        ^
- pure failing test 5ms
  Values not equal:

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

  installation.md#L29
      expect.eql("hello".size, 6)
                ^
- failing test with logs 8ms
  Values not equal:

  in expect.eql(- expected, + found)
  -2f2cfa67-ce6a-4499-9b19-b854791a422a
  +18005675-4089-4dcf-abef-ceb6053c5a9a

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

    [INFO] 10:24:06 [installation.md:35] x : 2f2cfa67-ce6a-4499-9b19-b854791a422a
    [INFO] 10:24:06 [installation.md:37] y : 18005675-4089-4dcf-abef-ceb6053c5a9a

Total 3, Failed 3, Passed 0, Ignored 0

Other suites

Weaver also includes support for