I ran the Play Framework website using "activator -jvm-debug 9999 ~run" command as stated in the documentation and used "Remote Java Application" debug configuration in Scala IDE. From the Debug perspective, it looks it's connected.
However no breakpoint is ever hit. Is there a way to fix it, please?
The reason it didn't work was hidden in the build.sbt, the fork in run was set to true.
With setting
fork in run := false
the debugger works.
1st I would recommend to use simply sbt: sbt -jvm-debug 9999 run
2nd, you need to connect the scala IDE to the jvm process (never did in Scala IDE, just Intellij, but found this docs)
finally, there are some (rare) problems in more complex scala lines of code. Try to set the breakpoint in more simple lines (declarations of values for instance)
Related
I am beginner in Scala. I cant find how to add SBT Console.
I have sbt shell, but in Scala course i see that they have both: SBT Shell and SBT Console, and using the second one. I tried to write "console" in sbt shell, and after "run", but it says:
error: not found: value run.
So I just want to add somehow this SBT Console, to run my program not only from button "run" in Intellij.
And what about SBT? Is it really needed? Or can i dont use it for Scala?
You're probably confused by "Shell" and "Console" usually being synonyms, but they actually mean different things with sbt.
sbt shell - is, uhm, a shell that sbt gives you when you run it in interactive mode - i.e. when you just run sbt from your terminal. This gives you access to other exciting things, such as running the app (with run command), inspecting the build (inspect ...), running tests (test, obviously) and so on.
sbt console - is an interactive REPL (read-evaluate-perform-loop) that gives you scala as an interpreter - i.e. you can type in (or paste) some scala code, and it will be immediately compiled and evaluated - outputting the results. Sbt console is also available from sbt shell - by running console.
So, in order to run your program, you have two options (besides the IntelliJ "run" dialog):
From your terminal do sbt run
From your terminal do sbt, then wait for sbt to initialize, then in the sbt shell do just run.
Refer to sbt docs for more details on different ways to run sbt (spoiler: there's also "batch" mode, where you can run sbt run from your terminal - and it is exactly the same as sbt and then run).
Sbt Reference manual might also be helpful - specifically it covers the sbt console command.
And what about SBT? Is it really needed? Or can i dont use it for Scala?
It is not mandatory - you can run scala with maven, it's just a bit more involved to configure. However, if you allow a bit of personal opinion, I'd recommend using sbt with scala projects (and even with Java projects). For one simple reason - the build definition in sbt is essentially just scala code - you can use any language features, third part libraries and even custom code in your build - which sometimes comes very helpful. Compared to maven, I think it's a big step forward, as in maven you define the build using a XML-based "language" defined by the mvn tool and it's plugins - which is much less customizable.
However, gradle also has this advantage, so pick the tool that best suits your needs.
I worked some time with SBT and a text editor. Then, moved to Intellij, installed Scala plugin, and created a new project as in the picture here by choosing it to be based on SBT. Also, in the settings, I chose the SBT launcher to be custom, and made it point to the already-installed sbt.
I believe Intellij is probably calling SBT commands like sbt run and stuff in the background. My question: How can I see (a log of) these commands as they're called by Intellij to sbt and their responses? And as a plus: where can I edit them? I opened the "Edit Configurations" but couldn't find anything like sbt compile.
I believe Intellij shows the responses (e.g., [info] downloading...) below in the "Background Tasks", but
1. It doesn't log these responses and
2. It doesn't show the commands issued by Intellij to sbt.
Big picture/what I'd really want to do: have the IntelliSense features from Intellij and Scala plugin, but build and run from the terminal and not have any effects from Intellij on that.
The IntelliJ Scala plugin doesn't (yet) call sbt except for project import/refresh or if you have a run configuration that uses sbt. Compilation is done by the built-in compile server. If you prefer to use IntelliJ as an editor and run tasks from the sbt console, that usually works fine.
I don't understand the question well
do u want to see the SBT output? if you are using run/debug you will see both the command & the output in the run window (alt+4)
also intelliJ has a window called event log
I hope that help
Intellij reads the projects configuration from sbt and creates an equivalent configurations for its project format (either .idea folder or .ipr)
this is a similar question to yours but about maven, you may find helpful:
https://stackoverflow.com/a/30167052/2675679
I have a new Scala/sbt project set up in IntelliJ IDEA with ScalaTest and jUnit interface successfully installed as dependencies. I have one test that passes when I hit run or debug.
My problem is that it doesn't rerun if I change something. I have to hit run or debug again and then it runs and gives the expected response.
How do I set up IntelliJ IDEA (with or without sbt) to run all tests every time the code changes? Is it possible to run the tests related to the files that were changed only?
As answered in comment by Boris the Spider you can run
> ~test
from sbt shell. Hopefully sbt and IntelliJ can integrate better via sbt server, but I don't think it's currently possible.
I have a set of test cases that I want to debug (step by step, reading values, etc.). How can I setup my sbt build so that I can hookup an eclipse debugger?
I found a way to attach the Eclipse debugger. To the Build.scala project settings I add the following options:
//required for the javaOptions to be passed in
fork := true
javaOptions in (Test) += "-Xdebug"
javaOptions in (Test) += "-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005"
Then in Eclipse I can create a new Debug configuration (arrow next to the bug icon) of type Remote Java Application. There I can select Scala debugger (Socket Attach) and specify the port 5005.
Problem I now have is that I cannot set any breakpoints, but that's another question and might be related to the version of Scala IDE that I use.
Edit
Problems with setting the breakpoint had (most likely) something to do with the exotic constructions in my specs2 specification. I created a small object with a method in order to be able to set a breakpoint
object BreakPoint {
def set = {}
}
Using the Scala debugger through the remote connector works.
But if you want to avoid to go back and forth between sbt and Eclipse, you can load your project in Scala IDE using sbteclipse, and then run your specs2 tests from inside Scala IDE, in debug mode, using the JUnit launcher.
I am using sbt to build my Play 2.0 project. I managed to configure sbt to open a debugging port, attach an Eclipse remote debugger and enter a break point. I put the break point into one of my actions. But when the execution stops there, I cannot inspect any variable. I guess that sbt builds the Scala code without debugging information.
Does anybody know how to configure sbt to add debugging information? Or could it be a problem of my Scala IDE plugin for Eclipse or anything else?
Many thanks in advance!
To start Play in debug mode via sbt, run:
sbt -jvm-debug 9999 run
I did not find a solution for all problems I have with debugging but at least it works so that I can use it. Here is my status:
I am using sbt directly and cannot use -jvm-debug 9999. But I added the following to JAVA_OPTS in the sbt launch script:
-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=9999
This gives the possibility to connect an Eclipse remote debugger and get debugging information (if running Play in development mode).
The problem that still remains is that I don't get the popups showing variable information when pointing the mouse cursor on a variable. But this seems to be a problem with the Scala IDE plugin and not with Play, because I get the variable information in the variables view in the debugging perspective.
I found this to be the easiest solution : (using IntelliJ IDEA )
in IntelliJ :
Go to "edit run configurations"
Create a new remote configuration (port 9999, all other details leave with default values)
Go back to IntelliJ and run the new debug configuration (don't forget to put a break point)
From command line run :
sbt -jvm-debug 9999 run
I had the same problem in a modularized sbt build. Adding
javacOptions ++= Seq("-g")
to the build.sbt file, solved the problem of missing debug information in the compiled classes.