Maven JAR file only includes HTML files, not Scala classes

Question

I followed this guide to release a Scala / SBT JAR file in Maven.

I ran the sbt publishSigned and sbt sonatypeRelease for the spark-fast-tests 0.11.0 release and the JAR file was correctly built. See here. These commands come from the sbt-sonatype plugin.

For some reason, when I did the 0.12.0 release, the Maven JAR file only includes HTML files and images. For example, the downloaded JAR file contains this file com/github/mrpowers/spark/fast/tests/DatasetComparer.html, but doesn't include DatasetComparer.class.

The target/scala-2.11/spark-fast-tests_2.11-2.3.0_0.12.0.jar file also only includes the HTML files (either sbt publishSigned or sbt sonatypeRelease must have generated this JAR file).

When I run sbt package, the JAR file that's generated includes the Scala classes like com/github/mrpowers/spark/fast/tests/DatasetComparer.class, as expected.

spark-fast-tests is an open source project and here is the build.sbt file.

How can I include my project classes in the JAR file that's uploaded to Maven? Any tips / tricks on how to debug this better?

Answer 1

A little late to the party, but I had the same problem with spark-testing-base. It stems from the way you modify the artifactName:

artifactName := { (sv: ScalaVersion, module: ModuleID, artifact: Artifact) =>
  artifact.name + "-" + module.revision + "." + artifact.extension
}

which is probably copied from the official SBT docs. Note that the docs have the following hint below the code though:

(Note that in practice you rarely want to drop the classifier.)

My solution for spark-testing-base is the following:

  artifactName := { (sv: ScalaVersion, module: ModuleID, artifact: Artifact) =>
    Artifact.artifactName(sv, module, artifact).replaceAll(s"-${module.revision}", s"-${sparkVersion.value}${module.revision}")
  }

This should make sure to keep the classifier (and whatever additional things might go into the artifactName) and solved the problem of JAR files containing documentation instead of class files.

Answer 2

Analysing spark-fast-tests build.sbt I would make the following recommendations:

1. Add sbt-release to plugins.sbt to enable release process customisation:

   addSbtPlugin("com.github.gseitz"  % "sbt-release"   % "1.0.8")
   addSbtPlugin("org.xerial.sbt"     % "sbt-sonatype"  % "2.0")
   addSbtPlugin("com.jsuereth"       % "sbt-pgp"       % "1.1.0")
   

2. Create version.sbt at project root and move version setting out of build.sbt:

   version in ThisBuild := "0.12.1-SNAPSHOT"
   

3. Create sonatype.sbt at project root and move the following settings out of build.sbt:

   homepage := Some(url("https://github.com/mrpowers/spark-fast-tests/"))
   scmInfo := Some(
       ScmInfo(
       url("https://github.com/mrpowers/spark-fast-tests/"),
       "[email protected]:mrpowers/spark-fast-tests.git"
       )
   )
   developers := List(
       Developer(
       "mrpowers",
       "Matthew Powers",
       "[email protected]",
       url("https://github.com/mrpowers/spark-fast-tests/")
       )
   )
   licenses += ("MIT", url("http://opensource.org/licenses/MIT"))
   publishMavenStyle := true
   

4. Add the following release settings to build.sbt:

   import sbtrelease.ReleaseStateTransformations._
   
   publishTo := Some(
     if (isSnapshot.value) { Opts.resolver.sonatypeSnapshots }
     else { Opts.resolver.sonatypeReleases }
   )
   
   releasePublishArtifactsAction := PgpKeys.publishSigned.value
   releaseProcess := Seq[ReleaseStep](
     checkSnapshotDependencies,
     inquireVersions,
     runClean,
     runTest,
     setReleaseVersion,
     commitReleaseVersion,
     tagRelease,
     publishArtifacts,
     setNextVersion,
     commitNextVersion,
     releaseStepCommand("sonatypeReleaseAll"),
     pushChanges
   )
   

5. Release to Maven Central with sbt release

For a working example have a look at build configuration of sbt-sonatype itself.