I can't add scala-reflect as dependency. My project/build.sbt looks like this:
//the name of the project, will become the name of the war file when you run the package command.
name := "Test-SBT"
version := "1.0"
//specify which Scala version we are using in this project.
scalaVersion := "2.10.3"
libraryDependencies <++= (scalaVersion)(sv =>
Seq(
"org.scala-lang" % "scala-reflect" % "2.10.3",
"org.scala-lang" % "scala-compiler" % "2.10.3"
)
)
And project/build.properties
sbt.version=0.13.0
And here is my Main class:
object Main1 extends App {
import scala.reflect.runtime.universe
val runtimeMirror = universe.runtimeMirror(getClass.getClassLoader)
//......
}
It says object runtime is not a member of package reflect. Of course, I did "gen-idea", "clean" and other things. What's up with that?
Guessing here due the question by #laughedelic.
The build.sbt should be in the root. Assuming the project you are writing is in test-sbt, you should end up with structure similar to:
test-sbt/build.sbt
test-sbt/project
Otherwise the build.sbt is used in creating the "internal compile project" used by SBT.
A deeper explanation can be found at SBT's docs sbt is recursive.
Related
I am trying to learn the basics of Scala, scalatest, and sbt and I'm following a tutorial. This is my built.sbt file:
name := "demo-hello"
version := "0.1"
scalaVersion := "2.12.6"
libraryDependencies += "org.scalatest" % "scalatest_2.10" % "2.1.0" % "test"
I have a test that looks like this (showing this is probably unnecessary:
package demo
import org.scalatest.FunSuite
class HelloTest extends FunSuite {
test("say hello method works correctly") {
val hello = new Hello
assert(hello.sayHello("Scala") == "Hello, Scala!")
}
}
What should I do from here? I am trying to run the test but I get this error:
Error:(8, 36) can't expand macros compiled by previous versions of Scala
assert(hello.sayHello("Scala") == "Hello, Scala!")
I'm not that familiar with the % symbol btw.
FIX
I changed my build.sbt to this:
name := "demo-hello"
version := "0.1"
scalaVersion := "2.10"
libraryDependencies += "org.scalatest" % "scalatest_2.10" % "2.1.0" % "test"
Remaining questions:
So it seems downgrading to scalaVersion "2.10" worked. Why?
What is an artifact? scalatest is apparently an artifact?
Where is scalaversion 2.10 kept on my machine? It seems I only have scala 2.12. Where in my project folder is version 2.10?
Answering your questions slightly out-of-order:
2 - An "artifact" is something that's built by maven, sbt, or another build system. For Scala or Java, this is almost always a jar file. Each item in libraryDependencies specifies a file in a maven repository (a database of artifacts).
1 - Scala class files are not compatible between minor versions of Scala. When you download a Scala jar from a maven repository, the Scala version is specified as part of the artifact name. The _2.10 in your dependency declares that you wish to use the version of scalatest that's compile for Scala 2.10 - which is why you were getting an error using it in your Scala 2.12 application.
When declaring dependencies on Scala artifacts in sbt, you should always use the %% operator, which automatically appends the appropriate suffix to your artifact, like so:
// This works for any scalaVersion setting.
libraryDependencies += "org.scalatest" %% "scalatest" % "2.1.0" % "test"
3 - sbt handles downloading the appropriate runtime files for the declared version of Scala automatically.
I want to build a 2.11 and 2.12 version of my project, so I have something like this in my Build.scala file:
val scalaVer12 = "2.12.1"
val scalaVer = "2.11.8"
lazy val basicSettings = Seq(
// lots of other settings
scalaVersion := scalaVer
)
The fly in the soup is I have a dependency on scala reflection, which is based on the scala version. Before I did this:
val scala_reflect = "org.scala-lang" % "scala-reflect" % Build.scalaVer
How can I modify this dependency line so that sbt will use either the 2.11 or 2.12 dependency based upon the version it's currently building?
lazy val bla = project in file("bla")
.settings(
libraryDependencies ++= Seq(
"org.scala-lang" % "scala-reflect" % scalaVersion.value
)
)
Never alias dependencies like that, it's clean to have an object to store version numbers, but not more, it's just a smell, especially since deps are often Scala version dependent and you can apply all sorts of rules to them.
I am using Playframework 2.5.4 to serve as REST API endpoint in default sbt build, compile & run with activator.
This play module imports a core module in local maven (3.9), where types were defined. Such as:
package com.myCompany
case class User(
id: Option[UUID] = None,
username: String
)
Then play controller package will import com.myCompany.User.
Issue is, when activator compiles, it gives unknown parameter name: username
If I placed case class in play's models package, it compiles without error.
Below is my build.sbt
name := """api"""
version := "1.0-SNAPSHOT"
lazy val root = (project in file(".")).enablePlugins(PlayScala)
scalaVersion := "2.11.8"
libraryDependencies ++= Seq(
jdbc,
cache,
ws,
filters,
"com.myCompany" % "core" % "1.0-SNAPSHOT"
)
routesGenerator := InjectedRoutesGenerator
resolvers ++= Seq(
"scalaz-bintray" at "http://dl.bintray.com/scalaz/releases",
Resolver.mavenLocal
// "Local Maven Repository" at "file:///home/pocheng/.m2/repository"
)
I suspect build.sbt file is having issue. Would appreciate any pointer. Thanks.
I have installed Eclipse Luna. Then I installed Scala IDE via Help -> Install new software and adding software site with link from here. Then I installed sbt 0.13 and sbteclipse using this mini-guide and created eclipse project. Then I installed (kindda) scalatest by adding it to my build.sbt. Now it looks like this:
val scalaTest = "org.scalatest" % "scalatest_2.11" % "2.2.4" % "test"
lazy val commonSettings = Seq(
scalaVersion := "2.11.6"
)
lazy val root = (project in file(".")).
settings(commonSettings: _*).
settings(
libraryDependencies += scalaTest
)
Then I created a test from this example. The file called FirstSpec.scala is located in testProject/src/test/scala-2.11/testProject/. So here is a problem: eclipse seems to not see scalaTest. The second line with import org.scalatest._ is underlined red with error description object scalatest is not a member of package org. And, following this guide, I don't see the option Run As -> ScalaTest - Suite when choosing my test class.
At the same time everything goes good and fine when I start sbt session in my test project and type test command. The tests launches and passes.
So my questions are:
why eclipse doesn't see the scalatest if I put it in build.sbt's libraryDependencies? What's the point of libraryDependencies then?
Why sbt test runs the tests without a problem? If sbt sees scalatest, why eclipse can't?
Whew, this one resolved my issue. So, build.sbt example might go something like:
import com.typesafe.sbteclipse.plugin.EclipsePlugin._
EclipseKeys.withSource := true
val scalaTest = "org.scalatest" % "scalatest_2.11" % "2.2.4" % "test"
val jodaConvert = "org.joda" % "joda-convert" % "1.7"
val joda = "joda-time" % "joda-time" % "2.7"
lazy val commonSettings = Seq(
scalaVersion := "2.11.6"
)
lazy val root = (project in file(".")).
settings(commonSettings: _*).
settings(
libraryDependencies += scalaTest
).
settings(
libraryDependencies += jodaConvert
).
settings(
libraryDependencies += joda
)
Then do this:
rm -rf ~/.ivy2/cache/
sbt update-classifiers
sbt eclipse
I am building a simple Scala project with SBT 0.11.
All the code files are in ~/MyProject/src/main/scala/
~/MyProject/build.sbt is the following
name := "MyProject"
version := "1.0"
scalaVersion := "2.9.1"
libraryDependencies ++= Seq(
"mysql" % "mysql-connector-java" % "5.1.+",
"c3p0" % "c3p0" % "0.9.1.2",
"org.apache.commons" % "commons-lang3" % "3.0.1",
"commons-lang" % "commons-lang" % "2.6",
"javassist" % "javassist" % "3.12.1.GA"
)
~/MyProject/project/Build.scala is the following
import sbt._
object MyProjectBuild extends Build {
lazy val MyProject = Project("MyProject", file("."))
}
This seems to work almost fine. The project does compile and run. The project name is set correctly (if I don't use Build.scala, then the name seems to appear something like "default-????", despite it being specified in build.sbt).
But the problem is that dependencies do not seem to work - update command doesn't download anything. How to fix this? Do I need to specify my dependencies in Build.scala rather than in build.sbt in this case?
Is it possible that you've already retrieved the project dependencies, but don't realize it because they are stored in the Ivy cache? You can view the managed classpath from the SBT console with the command
show managed-classpath
Recent versions of SBT do not store the managed dependencies in the project directory, unless the project is configured to do so. If you want, you can add the following to your build.sbt file:
retrieveManaged := true
This will create a ~/MyProject/lib_managed/ directory and contents.