Edit

Coming from ScalaTest

If you only use basic ScalaTest features, you should be able to replace usage of org.scalatest.FunSuite with minimal changes like below.

- import org.scalatest.munit.AnyFunSuite
- import org.scalatest.FunSuite
+ import munit.FunSuite

- class MySuite extends FunSuite with BeforeAll with AfterAll {
+ class MySuite extends FunSuite {
  test("name") {
    // unchanged
  }

- ignore("ignored") {
+ test("ignored".ignore) {
    // unchanged
  }

Optionally, replace usage of assert(a == b) with assertEquals(a, b) to improve the error message in failed assertions:

- assert(a == b)
+ assertEquals(a, b)

Or if you are using match-style assertions via with Matchers, change the assertions like so:

- result shouldEqual Some(Name(first, last))
+ assertEquals(result, Some(Name(first, last)))

MUnit doesn't ship with a large set of assertions, so some fancier matchers will have to be converted to a simple assertion:

- myList should have size 2
+ assertEquals(myList.length, 2)

If you are coming from WordSpec style tests, make sure to flatten them, or your tests will not run. (Only the outer test will be selected to run, and the inner tests will do nothing).

-class FooSpec extends AnyWordSpec with Matchers {
+class FooSpec extends FunSuite {
-  "Foo" must {
-    "succeed" in {
+  test("Foo must succeed") {
...
-    }