I have a subproject named oppenheimer in my project. It's very simple to run this project from the sbt console.
[myproject] $ oppenheimer/run
I can also pass in a command line argument as such:
[myproject] $ oppenheimer/run migrate
[myproject] $ oppenheimer/run clean
How can I do this from build.sbt? Is it possible to define a task that does this? It would suffice to have something like this:
val customMigrate = ...
val customClean = ...
And this is so that I could use it elsewhere in the project, like such:
(test in Test) <<= (test in Test).dependsOn(customMigrate)
The answer is given in the sbt FAQ section "How can I create a custom run task, in addition to run?". Basically:
lazy val customMigrate = taskKey[Unit]("custom run task")
fullRunTask(customMigrate, Test, "foo.Main", "migrate")
Related
I know, I saw Run custom task automatically before/after standard task but it seems outdated. I also found SBT before/after hooks for a task but it does not have any code example.
I am on SBT 0.13.17.
So I want to run my task MyBeforeTask and MyAfterTask automatically after an other tasks, says Compile.
So when you do sbt compile I would like to see:
...log...
This is my before test text
...compile log...
This is my after test text
So I would need to have:
object MyPlugin extends AutoPlugin {
object autoImport {
val MyBeforeTask = taskKey[Unit]("desc...")
val MyAfterTask = taskKey[Unit]("desc...")
}
import autoImport._
override def projectSettings: Seq[Def.Setting[_]] = {
MyBeforeTask := {
println("This is my before test text")
},
MyAfterTask := {
println("This is my after test text")
}
}
}
So I think I need things like dependsOn and in but I am not sure how to set them up.
It is not possible to configure for a particular task to run after the given task, because that's not how the task dependencies model works - when you specify the task, its dependencies and itself will be executed, but there is no way to define an "after" dependency. However, you can simulate that with dynamic tasks.
To run some task before another, you can use dependsOn:
compile in Compile := (compile in Compile).dependsOn(myBeforeTask).value
This establishes a dependency between two tasks, which ensures that myBeforeTask will be run before compile in Compile.
Note that there is a more generic way to make multiple tasks run one after another:
aggregateTask := Def.sequential(task1, task2, task3, task4).value
Def.sequential relies on the dynamic tasks machinery, which sets up dependencies between tasks at runtime. However, there are some limitations to this mechanism, in particular, you cannot reference the task being defined in the list of tasks to execute, so you can't use Def.sequential to augment existing tasks:
compile in Compile := Def.sequential(myBeforeTask, compile in Compile).value
This definition will fail at runtime with a strange error message which basically means that you have a loop in your task dependencies graph. However, for some use cases it is extremely useful.
To run some task after another, however, you have to resort to defining a dynamic task dependency using Def.taskDyn:
compile in Compile := Def.taskDyn {
val result = (compile in Compile).value
Def.task {
val _ = myAfterTask.value
result
}
}.value
Def.taskDyn accepts a block which must return a Def.Initialize[Task[T]], which will be used to instantiate a task to be run later, after the main body of Def.taskDyn completes. This allows one to compute tasks dynamically, and establish dependencies between tasks at runtime. As I said above, however, this can result in very strange errors happening at runtime, which are usually caused by loops in the dependency graph.
Therefore, the full example, with both "before" and "after" tasks, would look like this:
compile in Compile := Def.taskDyn {
val result = (compile in Compile).value
Def.task {
val _ = myAfterTask.value
result
}
}.dependsOn(myBeforeTask).value
I have a subproject in my build.sbt with a rather long setting for initialCommands, comprising a list of imports and some definitions. I'd like to test this as part of regular CI, because otherwise I won't notice breaking changes after refactoring code. It is not clear to me how to do so.
Just running sbt console doesn't seem to cut it, because there is always a "successful" exit code even when code doesn't compile.
Moving the code out into an object defined in a special source file won't help because I need the list of imports to be present (and I don't want to cakeify my whole code base).
Moving the code out into a source file and then loading that with :load also always gives a successful exit code.
I found out about scala -e but that does strange things on my machine (see the error log below).
This is Scala 2.12.
$ scala -e '1'
cat: /release: No such file or directory
Exception in thread "main" java.net.UnknownHostException: <my-host-name-here>: <my-host-name-here>: Name or service not known
You could generate a file and run it like any other test file:
(sourceGenerators in Test) += Def.task {
val contents = """object TestRepl {
{{}}
}""".replace("{{}}", (initialCommands in console).value)
val file = (sourceManaged in Test).value / "repltest.scala"
IO.write(file, contents)
Seq(file)
}.taskValue
There are a number of Q&A about how to send command line args to sbt run . My question is: how to specify the command line args in a hard-coded manner within build.sbt - where we know how to specify the class itself:
mainClass in Global := Some("mypackage.MyMainClas")
We need to specify the command line parameters in a hardcoded manner in build.sbt due to our toolchain.
You can try create custom run task with the default arguments, like:
lazy val myParameters = Array("arg1", "arg3")
lazy val myRunTask = taskKey[Unit]("A custom run task.")
fullRunTask(myRunTask, Runtime, "mypackage.MyMainClas", myParameters: _*)
and run with: sbt myRunTask.
Reference:
http://www.scala-sbt.org/0.13/docs/Faq.html#How+can+I+create+a+custom+run+task%2C+in+addition+to+%3F
I want to define a compound task in sbt so that all tasks that are run in my CI job can be executed in a single commmand. For example at the moment I am running:
clean coverage test scalastyle coverageReport package
However I'd like to just run
ci
Which would effectively be an alias to all of the above tasks. Furthermore I'd like to define this in a scala file (as opposed to build.sbt) so I can include it in an already existing common scala plugin and thus it becomes availbale to all my projects.
So far (after much reading of the docs) I've managed to get a task that depends just on scalastyle by doing:
lazy val ci = inputKey[Unit]("Prints 'Runs All tasks for CI")
ci := {
val scalastyleResult = (scalastyle in Compile).evaluated
println("In the CI task")
}
however if I attempt to add another task (say the publish task) e.g:
ci := {
val scalastyleResult = (scalastyle in Compile).evaluated
val publishResult = (publish in Compile).evaluated
println("In the CI task")
}
this fails with:
[error] [build.sbt]:52: illegal start of simple expression
[error] [build.sbt]:55: ')' expected but '}' found.
My first question is whether this approach is indeed the correct way to define a compound task.
If this is the case, then how can I make the ci task depend on all the tasks mentioned.
lazy val ci = inputKey[Unit]("Prints 'Runs All tasks for CI")
ci := {
Put a blank space between statements
lazy val ci = inputKey[Unit]("Prints 'Runs All tasks for CI")
ci := {
Also, know that SBT will run your dependent tasks of ci in parallel. Sometimes this is good, but not always, for example in your clean.
There are several ways to run tasks in sequence.
One way:
commands += Command.command("ci") {
"clean" ::
"coverage" ::
"test" ::
"scalastyle" ::
"coverageReport" ::
_
}
I have a Scala script that looks something like:
#!/bin/sh
PATH=${SCALA_HOME}:${PATH}
exec scala "$0" "$#"
!#
Console.println("Hello, world!")
Is there some way in Gradle to set the version of Scala to be used, have it implicitly set SCALA_HOME, and execute the script?
There is no built-in feature for this. The way to tackle this is to declare two tasks: A Copy task that downloads the Scala distribution and unpacks it to a local directory, and an Exec task that sets the SCALA_HOME environment variable to the copy task's output directory and executes your script.
Here is an example of executing Scala from Gradle. It is a nascent attempt to build a plugin using Scalafmt. Of note is how nasty it is to use static values.
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath 'com.geirsson:scalafmt-core_2.11:0.4.2'
}
}
task scalafmt << {
String target = "object FormatMe { List(Split(Space, 0).withPolicy(SingleLineBlock(close)), Split(Newline, 1).withPolicy{ case Decision(t#FormatToken(_, `close`, _), s) => Decision(t, List(Split(Newline, 0)))}.withIndent(2, close, Right)) }"
def config = org.scalafmt.config.ScalafmtConfig$.MODULE$.default
def range = scala.collection.immutable.Set$EmptySet$.MODULE$
println org.scalafmt.Scalafmt.format(target, config, range).formattedCode()
}
I know this is not quite on topic but I couldn't find anywhere else to put this and I hope it is of some value to people who ended up here for the same reason I did.
Gradle has an Exec task in which you can set the environment to be passed to the new process. You could pass SCALA_HOME through that.