scalatest : object scalatest is not a member of package org

EDIT : It works if the file is in src/test/scala/tests/ but not in src/main/scala/mypackage/. Why?

I have tried solutions from topics with people having nearly the same issue but none of them work.

For details, I have this in build.sbt :

libraryDependencies ++= Seq(
   ...
  "org.scalatest" % "scalatest_2.10" % "2.2.1" % "test",
   ...

In Intellij, I have a class with:

import org.scalatest.{BeforeAndAfterAll, Suite}

with {BeforeAndAfterAll, Suite} in red so i guess scalatest is found

sbt package does not work either:

object scalatest is not a member of package org [error] import org.scalatest. {BeforeAndAfterAll, Suite}

I have already tried this :

sbt clean update
restart + invalidate cache of intellij
remove .idea/ and reimport
libraryDependencies += "org.scalatest" % "scalatest_2.10" % "2.0" % "test" instead ogf the actual
magical ritual on my keyboard

Nothing works

Any ideas?

Solution

You should take a look at sbt project structure:

src/
  main/
    resources/
       <files to include in main jar here>
    scala/
       <main Scala sources>
    java/
       <main Java sources>
  test/
    resources
       <files to include in test jar here>
    scala/
       <test Scala sources>
    java/
       <test Java sources>

Your scala tests should go under src/test/scala/.

If you really want to use scalatest in main (and you know what you are trying to do), try this:

  "org.scalatest" % "scalatest_2.10" % "2.2.1",

In your original build.sbt, "test" is the configuration and it means that scalatest will only be on the test classpath and it isn’t needed by the main sources. This is generally good practice for libraries because your users don’t typically need your test dependencies to use your library (ref).