Scala.js 1.0.1 support

[tindzk]

I am trying to use MUnit with Scala.js 1.0.1 and Scala 2.13, but the linker is encountering errors:

$ sbt test
[...]
[info] Fast optimizing /tmp/testtest/munit-scalajs-10/root/target/scala-2.13/root-test-fastopt.js
[error] munit.internal.JSFs$ needs to be imported from module 'fs' but module support is disabled.
[error] munit.internal.JSPath$ needs to be imported from module 'path' but module support is disabled.
[error] There were module imports without fallback to global variables, but module support is disabled.
[error] To enable module support, set `scalaJSLinkerConfig ~= (_.withModuleKind(ModuleKind.CommonJSModule))`.
[error] (root / Test / fastOptJS) There were module imports without fallback to global variables, but module support is disabled.
[error] To enable module support, set `scalaJSLinkerConfig ~= (_.withModuleKind(ModuleKind.CommonJSModule))`.

Here is a minimal sbt project exhibiting the faulty behaviour.

I have also tried it with Bloop (using scalacenter/bloop#1234) and am getting the following errors:

[E] org.junit.runner.Runner (of kind Class) is not a valid interface implemented by munit.MUnitRunner (of kind Class)
[E]   called from munit.MUnitRunner
[E]   called from private munit.internal.PlatformCompat$.$anonfun$newRunner$1(scala.scalajs.reflect.InstantiatableClass)munit.MUnitRunner
[E]   called from munit.internal.PlatformCompat$.newRunner(sbt.testing.TaskDef,java.lang.ClassLoader)scala.Option
[E]   called from munit.internal.junitinterface.JUnitTask.execute(sbt.testing.EventHandler,[sbt.testing.Logger,scala.Function1)void
[E]   called from private org.scalajs.testing.bridge.HTMLRunner$.$anonfun$scheduleTask$1(sbt.testing.Task,org.scalajs.testing.bridge.HTMLRunner$EventCounter$Handler,org.scalajs.testing.bridge.HTMLRunner$UI$TestTask,scala.concurrent.Promise)void
[E]   called from private org.scalajs.testing.bridge.HTMLRunner$.scheduleTask(sbt.testing.Task,org.scalajs.testing.bridge.HTMLRunner$UI)scala.concurrent.Future
[E]   called from private org.scalajs.testing.bridge.HTMLRunner$.$anonfun$runTests$1(org.scalajs.testing.bridge.HTMLRunner$UI,sbt.testing.Task)scala.concurrent.Future
[E]   called from private org.scalajs.testing.bridge.HTMLRunner$.runAllTasks$1(scala.collection.Seq,org.scalajs.testing.bridge.HTMLRunner$UI)scala.concurrent.Future
[E]   called from private org.scalajs.testing.bridge.HTMLRunner$.runTests(sbt.testing.Framework,scala.collection.immutable.Seq,org.scalajs.testing.bridge.HTMLRunner$UI)scala.concurrent.Future
[E]   called from private org.scalajs.testing.bridge.HTMLRunner$.$anonfun$onLoad$10(scala.Function1,org.scalajs.testing.bridge.HTMLRunner$UI,scala.Tuple2)scala.concurrent.Future
[E]   called from private org.scalajs.testing.bridge.HTMLRunner$.onLoad(org.scalajs.testing.common.IsolatedTestSet)void
[E]   called from org.scalajs.testing.bridge.HTMLRunner$.org$scalajs$testing$bridge$HTMLRunner$$$anonfun$start$1(org.scalajs.testing.common.IsolatedTestSet)void
[E]   called from org.scalajs.testing.bridge.HTMLRunner$.start(org.scalajs.testing.common.IsolatedTestSet)void
[E]   called from org.scalajs.testing.bridge.Bridge$.start()void
[E]   called from static org.scalajs.testing.bridge.Bridge.start()void
[E]   called from core module module initializers
[E] involving instantiated classes:
[E]   munit.internal.PlatformCompat$
[E]   munit.internal.junitinterface.JUnitTask
[E]   org.scalajs.testing.bridge.HTMLRunner$
[E]   org.scalajs.testing.bridge.Bridge$

The Bloop classpath looks fine though:

"classpath" : [
	"/home/tim/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-js/scalajs-junit-test-runtime_2.13/1.0.1/scalajs-junit-test-runtime_2.13-1.0.1.jar",
	"/home/tim/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-js/scalajs-library_2.13/1.0.1/scalajs-library_2.13-1.0.1.jar",
	"/home/tim/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-js/scalajs-test-bridge_2.13/1.0.1/scalajs-test-bridge_2.13-1.0.1.jar",
	"/home/tim/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-js/scalajs-test-interface_2.13/1.0.1/scalajs-test-interface_2.13-1.0.1.jar",
	"/home/tim/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.2/scala-library-2.13.2.jar",
	"/home/tim/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-reflect/2.13.2/scala-reflect-2.13.2.jar",
	"/home/tim/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scalameta/munit_sjs1_2.13/0.7.3/munit_sjs1_2.13-0.7.3.jar",
	"/tmp/build-test-scalajs-10/bloop/example"
]

[olafurpg]

Thank you for reporting! Have you tried updating scalaJSLinkerConfig as the message recommends?

[tindzk]

Thanks. I investigated both issues.

Yes, the linking errors disappear after setting the module kind to CommonJS. Is MUnit supposed to only work when emitting CommonJS modules?

As for Bloop, I could fix it by placing scalajs-test-interface_2.13-1.0.1.jar after munit_sjs1_2.13-0.7.3.jar in the classpath (mimicking sbt's classpath). Is this intentional? I could implement a workaround in Seed, but would prefer if the classpath was sorted.

[olafurpg]

I accidentally marked the issue as closed.

Yes, the linking errors disappear after setting the module kind to CommonJS. Is MUnit supposed to only work when emitting CommonJS modules?

MUnit has a few facades for java.nio.file types here

https://github.com/scalameta/munit/blob/f61429f66f8fd81ee71e6c10dc2fe212073b5b07/munit/js/src/main/scala/munit/internal/JSIO.scala

If there is an alternative way to achieve the same functionality without the CommonJS module requirement then I'm happy to merge a PR making such a change.

As for Bloop, I could fix it by placing scalajs-test-interface_2.13-1.0.1.jar after munit_sjs1_2.13-0.7.3.jar in the classpath (mimicking sbt's classpath). Is this intentional? I could implement a workaround in Seed, but would prefer if the classpath was sorted.

Does Seed sort the classpath? If so, what sorting do you use? The ordering of jars has significant meaning and the control over the ordering should ideally be left to end users.

The cause of this issue is likely that MUnit contains interfaces for JUnit here https://github.com/scalameta/munit/tree/f61429f66f8fd81ee71e6c10dc2fe212073b5b07/munit/non-jvm/src/main/scala/org/junit It looks like org.junit.runner.Runner is an empty abstract class in Scala.js while it's a trait in MUnit

https://github.com/scala-js/scala-js/blob/55a0b28977329c112873207c3483881a585f3f62/junit-runtime/src/main/scala/org/junit/runner/Runner.scala#L6

munit/munit/non-jvm/src/main/scala/org/junit/runner/Runner.scala

Line 5 in f61429f

trait Runner {

We may be able to fix the issue by changing the MUnit runner to be an abstract class instead to match the actual JUnit Runner
https://junit.org/junit4/javadoc/4.12/org/junit/runner/Runner.html

[tindzk]

Thanks for your thorough analysis!

The facades look correct. Reading the documentation, the Namespace type should be compatible with ECMAScript 2015 which is the default module kind since Scala.js 1.0.

Seed sorts the classpath by name using Scala's sorted. Since the ordering matters indeed, I will remove it. This will not solve the issue though as the same linking error occurs when scalajs-junit-test-runtime_2.13 is placed before munit (which is correct since munit depends on scalajs-junit-test-runtime). However, it did work with your suggested fix which I have submitted as a pull request (#120).

[olafurpg]

Sounds good! I triggered a 0.7.5 release with your fix!

[tindzk]

Thanks!