I am having issues with the sbt-uglify plugin in my Play application. I have followed the documentation exactly from https://github.com/sbt/sbt-uglify.
In my plugins.sbt I add the plugin:
addSbtPlugin("com.typesafe.sbt" % "sbt-uglify" % "1.0.3")
In my build.sbt I add uglify to the asset pipeline:
pipelineStages := Seq(uglify, digest, gzip)
I have at least 60 JavaScript files that are being optimized with uglify when I run: sbt start or sbt dist. I begin to see several warnings:
[error] WARN: Dropping unused function argument
[error] WARN: Dropping unused function argument
[error] WARN: Dropping unreachable code
I am used to seeing this when I run a similar project with fewer JS files. This continues until it gets to the point of no memory:
[error] java.lang.OutOfMemoryError: unable to create new native thread
I found a similar question being asked about this: Play 2.3.6 Java - OutOfMemory errors w/ sbt-uglify. This didn't seem to be answered and I had already tried increasing my memory limit.
The funny thing is that I can get it to work fine with RequireJS, which should be doing the exact same thing. I should be able to use either, correct?
Has anyone else encountered this problem or know a solution? I am not completely sure if this is an issue with Play, Uglify, or what.
I have added a test example that replicates this issue that you can clone and try for yourself: https://github.com/ascreamingweas/Sbt-Uglify-Test
Your help is appreciated.
I was having the same problem, the sbt-js-engine seems to have solved the issue :
Just make sure you add the plugin
ddSbtPlugin("com.typesafe.sbt" % "sbt-js-engine" % "1.0.2")
Also don't forget to install NodeJS either add
JsEngineKeys.engineType := JsEngineKeys.EngineType.Node
or
export SBT_OPTS="$SBT_OPTS -Dsbt.jse.engineType=Node"