The Scala Toolkit

What else can MUnit do?

Language

You can require the entire toolkit in a single line:

//> using toolkit latest

MUnit, being a testing framework, is only available in test files: files in a test directory or ones that have the .test.scala extension. Refer to the Scala CLI documentation to learn more about the test scope.

Alternatively, you can require just a specific version of MUnit:

//> using dep org.scalameta::munit:1.0.0-M7

In your build.sbt file, you can add the dependency on toolkit-test:

lazy val example = project.in(file("."))
  .settings(
    scalaVersion := "3.3.3",
    libraryDependencies += "org.scala-lang" %% "toolkit-test" % "0.1.7" % Test
  )

Here the Test configuration means that the dependency is only used by the source files in src/test.

Alternatively, you can require just a specific version of MUnit:

libraryDependencies += "org.scalameta" %% "munit" % "1.0.0-M7" % Test

In your build.sc file, you can add a test object extending Tests and TestModule.Munit:

object example extends ScalaModule {
  def scalaVersion = "3.3.3"
  object test extends Tests with TestModule.Munit {
    def ivyDeps =
      Agg(
        ivy"org.scala-lang::toolkit-test:0.1.7"
      )
  }
}

Alternatively, you can require just a specific version of MUnit:

ivy"org.scalameta::munit:1.0.0-M7"

Adding clues to get better error report

Use clue inside an assert to a get a better error report when the assertion fails.

assert(clue(List(a).head) > clue(b))
// munit.FailException: assertion failed
// Clues {
//   List(a).head: Int = 1
//   b: Int = 2
// }

Learn more about clues in the MUnit documentation.

Writing environment-specific tests

Use assume to write environment-specific tests. assume can contain a boolean condition. You can check the operating system, the Java version, a Java property, an environment variable, or anything else. A test is skipped if one of its assumptions isn’t met.

import scala.util.Properties

test("home directory") {
  assume(Properties.isLinux, "this test runs only on Linux")
  assert(os.home.toString.startsWith("/home/"))
}
import scala.util.Properties

test("home directory") {
  assume(Properties.isLinux, "this test runs only on Linux")
  assert(os.home.toString.startsWith("/home/"))
}

Learn more about filtering tests in the MUnit documentation.

Tagging flaky tests

You can tag a test with flaky to mark it as being flaky. Flaky tests can be skipped by setting the MUNIT_FLAKY_OK environment variable to true.

test("requests".flaky) {
  // I/O heavy tests that sometimes fail
}
test("requests".flaky) {
  // I/O heavy tests that sometimes fail
}

Learn more about flaky tests in the MUnit documentation

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