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Release notes

v0.1.15​

The M1 native launcher is here! (experimental)​

We are happy to announce that there is a new dedicated launcher for M1 users. You can find it here.

Please note that the package sub-command is unstable for this launcher.

Added in #1396 by @lwronski

--python option for repl sub-command (experimental)​

Passing the --python option allows using ScalaPy with the repl sub-command:

▶ scala-cli --python
Welcome to Scala 3.2.0 (17.0.2, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.
                                                                                
scala> import me.shadaj.scalapy.py
                                                                                
scala> py.Dynamic.global.range(1, 4)
val res0: me.shadaj.scalapy.py.Dynamic = range(1, 4)

Added in #1336 by @alexarchambault

-d, -classpath and compile sub-command's --output options changes​

To be backward compatible with the scala command, some changes have been made to the following options:

  • The compile sub-command's --output option has been renamed to --compilation-output. This option is now also available from the run and package sub-commands.
▶ scala-cli compile Hello.scala --compilation-output out
▶ scala-cli --main-class Hello -classpath out
Hello
  • The -d option is no longer an alias for --dependency, but for --compilation-output.
    • -O -d -O path/to/compilation/output now defaults to -d path/to/compilation/output.
▶ scala-cli compile Hello.scala -d out
▶ scala-cli --main-class Hello -classpath out
Hello
  • The old --classpath option has been renamed to --print-classpath.
    • --classpath, --class-path and -classpath options are now aliases for the --extra jars option.
    • -O -classpath -O path/to/classpath now defaults to --extra-jars path/to/classpath.
▶ scala-cli compile --print-classpath Hello.scala
# ~/Projects/debug-test/.scala-build/project_103be31561_103be31561-7a1ed8dde0/classes/main:~/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala3-library_3/3.2.0/scala3-library_3-3.2.0.jar:~/Library/Caches/ScalaCli/local-repo/v0.1.15/org.virtuslab.scala-cli/runner_3/0.1.15/jars/runner_3.jar:~/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.8/scala-library-2.13.8.jar

Added in #1340 by @Gedochao

Make inputs optional when -classpath and --main-class are passed​

The following changes have been made to improve backward compatibility with the scala command:

  • Passing the --main-class option along with -classpath to the default command now defaults to run instead of repl:
▶ scala-cli --main-class Hello -classpath out
Hello
  • If the run sub-command is passed explicitly, it's sufficient to have a main class on the classpath (inputs aren't necessary then):
▶ scala-cli compile Hello.scala -d out
▶ scala-cli run -classpath out 
Hello

Added in #1369 by @Gedochao

Debugging with the run and test sub-commands​

It is now possible to debug code ran by run and test sub-commands:

▶ scala-cli Main.scala --debug
Listening for transport dt_socket at address: 5005
Hello

This addresses #1212

Added in #1389 by @wleczny

--platform option​

This option can be used to choose the platform, which should be used to compile and run the application.

▶ scala-cli Main.scala --platform js
Hello

Note that --platform js is an alias for --js and --platform native is an alias for --native.

This addresses #1214

Added in #1347 by @wleczny

Other changes​

Fixes​

  • Ensure directories are created recursively when the package sub-command is called by @Gedochao in #1371
  • Fix calculation of Scala version and turn off the -release flag for 2.12.x < 2.12.5 by @Gedochao in #1377
  • Fix finding main classes in external jars by @Gedochao in #1380
  • Fix Js split style SmallModulesFor in pure JVM by @lwronski in #1394

Build and internal changes​

Updates​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.14...v0.1.15

v0.1.14​

Hotfix printing stacktraces from Scala CLI runner for Scala 3.x < 3.2.0​

We fixed a nasty bug breaking any Scala CLI run using any Scala 3 version earlier than 3.2.0 on printing stacktraces. Only Scala CLI 0.1.13 was affected.

$ scala-cli about
Scala CLI version: 0.1.13
Scala version (default): 3.2.0
$ scala-cli -S 3.1.3 -e 'throw Exception("Broken")'
Compiling project (Scala 3.1.3, JVM)
Compiled project (Scala 3.1.3, JVM)
Exception in thread "main" java.lang.NoSuchMethodError: 'long scala.runtime.LazyVals$.getOffsetStatic(java.lang.reflect.Field)'
        at scala.cli.runner.StackTracePrinter.<clinit>(StackTracePrinter.scala:101)
        at scala.cli.runner.StackTracePrinter$.coloredStackTraces(StackTracePrinter.scala:104)
        at scala.cli.runner.StackTracePrinter$.$lessinit$greater$default$4(StackTracePrinter.scala:11)
        at scala.cli.runner.Runner$.main(Runner.scala:18)
        at scala.cli.runner.Runner.main(Runner.scala)

Added in #1358 by @romanowski

Build and internal changes​

Updates​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.13...v0.1.14

v0.1.13​

Change the default sub-command to repl when no args are passed​

We no longer default to the help sub-command when no arguments are passed. Starting with 0.1.13 running Scala CLI with no args will launch the repl.

$ scala-cli -S 3
Welcome to Scala 3.1.3 (17.0.3, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.

scala>

When inputs are provided, Scala CLI defaults to the run sub-command, as before.

$ cat hello.sc
println("Hello World")
$ scala-cli hello.sc
Hello World

This change was added by @Gedochao in #1268

Marking the project's workspace root with the project.settings.scala file​

Scala CLI now supports marking the workspace root directory with an optional configuration file: project.settings.scala. The workspace root determines where the .bsp and .scala-build directories will be saved (which mostly affects what path should be opened in your IDE to import the Scala CLI project through BSP).

The settings file is also the recommended input for your project's using directives. Otherwise, it functions similarly to other .scala sources.

$ cat project.settings.scala
//> using scala "2.13.4"
$ cat hello.sc
println(util.Properties.versionString)
$ scala-cli hello.sc .
version 2.13.4

To see how exactly is the root directory resolved, see this document

Added in #1260 by @wleczny

Scala CLI is now built with Scala 3.2.0​

We now rely on Scala 3.2.0 as the default internal Scala version used to build the project.

This change was added by @lwronski in #1314

Add resources support for Scala Native​

Scala CLI now allows embedding resources (by default) in a Scala Native binary with the --native flag.

$ cat resources/scala-native/foo.c 
int foo(int i) {
  return i + 42;
}
$ cat hello.scala 
//> using platform "native"
//> using resourceDir "resources"

import scalanative.unsafe.*

@extern
def foo(int: CInt): CInt = extern

@main def main =
  println(foo(3))
$ scala-cli hello.scala --native 
45

Added in #812 by @jchyb

Default to the run sub-command instead of repl when the -e, --execute-script, --execute-scala or --execute-java options are passed.​

Even though we default to the repl sub-command when no arguments are passed to Scala CLI, an exception to that rule is when a snippet is passed with one of the following options: -e, --execute-script, --execute-scala or --execute-java. In that case, the passed snippets are treated as inputs to be executed and switch the default to the run sub-command.

$ scala-cli -e 'println("Hello")'
Hello

If you still want to pass a snippet to the repl, you can either pass the repl sub-command explicitly or use one of the following options, as before: --script-snippet, --scala-snippet or --java-snippet.

$ scala-cli --script-snippet 'println("Hello")'
Welcome to Scala 3.1.3 (17.0.2, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.
                                                                                                                                                             
scala> snippet_sc.main(Array.empty)
Hello

This change was introduced to make the -e option backwards compatible with the scala command.

Added in #1313 by @Gedochao

Work in progress​

Support for Markdown (experimental)​

Scala CLI can now accept .md inputs and run/compile a snippet of Scala code inside the markdown. Markdown sources are ignored by default unless passed explicitly as inputs. You can also enable including non-explicit .md inputs by passing the --enable-markdown option.

Plain scala snippets are treated similarly to .sc scripts which can be run by scala-cli:

$ cat Example.md
This is a simple example of an `.md` file with a Scala snippet.

```scala
val message = "Hello from Markdown"
println(message)
```
scala-cli Example.md
Hello from Markdown

See this document for more details about the experimental Markdown support.

Added in #1268 by @Gedochao

Add --python option for the run sub-command (experimental)​

The run sub-command can now run ScalaPy when the --python option is passed.

$ cat helloscalapy.sc
import py.SeqConverters
val len = py.Dynamic.global.len(List(0, 2, 3).toPythonProxy)
println(s"Length is $len")
$ scala-cli helloscalapy.sc --python -S 2.13
Length is 3

Added in #1295 by @alexarchambault

Other changes​

Documentation​

Fixes​

Build and internal changes​

Updates​

New Contributors​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.12...v0.1.13

v0.1.12​

Add --spark, --spark-standalone and --hadoop options for the run sub-command​

The run sub-command can now run Spark jobs when the --spark option is passed.

$ scala-cli run --spark SparkJob.scala

Similarly, it's possible to run Hadoop jobs by passing the --hadoop option.

scala-cli run --hadoop HadoopJob.java

It's also possible to run Spark jobs without a Spark distribution by passing the --spark-standalone option.

$ scala-cli run --spark-standalone SparkJob.scala

Added in #1129 by alexarchambault

Add the default Scala version to the output of the version sub-command​

The version sub-command now includes both the Scala CLI version and the default Scala version.

$ scala-cli --version
Scala CLI version 0.1.12
Default Scala version: 3.1.3
$ scala-cli -version
Scala CLI version 0.1.12
Default Scala version: 3.1.3
$ scala-cli version
Scala CLI version 0.1.12
Default Scala version: 3.1.3

You can also pass the --cli-version option to only get the Scala CLI version or the --scala-version option to only get the default Scala version.

$ scala-cli version --cli-version
0.1.12
$ scala-cli version --scala-version
3.1.3

This is potentially a breaking change if your automation relies on the output of the version sub-command.

Added in #1262 by lwronski

Enable passing the scalafmt configuration with --scalafmt-conf and --scalafmt-conf-str​

It is now possible to pass a custom location of the scalafmt configuration with the --scalafmt-conf option for the fmt sub-command.

$ scala-cli fmt --scalafmt-conf path/to/the/conf/.scalafmt.conf

You can also pass the configuration straight from the terminal with --scalafmt-conf-str.

$ scala-cli fmt --scalafmt-conf-str  "version=3.5.5                                   
runner.dialect=scala213"

Added in #1227 by wleczny

Enable turning the --interactive mode on permanently​

It is now possible to set the --interactive mode on by default, so that passing it explicitly isn't necessary.

The next time when you run a command with the --interactive option set to on, Scala CLI will suggest to turn it on permanently.

This is recommended for environments where scala-cli is used by a human user only (and not by any automation).

$ scala-cli . --interactive
You have run the current scala-cli command with the --interactive mode turned on.
Would you like to leave it on permanently?
[0] Yes
[1] No
0
--interactive is now set permanently. All future scala-cli commands will run with the flag set to true.
If you want to turn this setting off at any point, just run `scala-cli config interactive false`.
Found several main classes. Which would you like to run?
[0] ScalaMainClass2
[1] ScalaMainClass1
[2] scripts.ScalaScript_sc

You can also configure it manually with the config sub-command, by setting the interactive property to true.

$ scala-cli config interactive true

Added in #1238 by Gedochao

Other changes​

Work in progress​

Documentation​

Build and internal changes​

Updates​

New Contributors​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.11...v0.1.12

v0.1.11​

Make .scalafmt.conf optional when running the fmt command​

Scala CLI can now run the fmt command without a .scalafmt.conf file present. Previously, if such a file was absent, a Scalafmt requires explicitly specified version. error was raised while using the fmt command.

The Scala CLI fmt command now supports passing the scalafmt version and dialect directly from the command line, using the --scalafmt-dialect and --scalafmt-version options respectively:

scala-cli fmt --scalafmt-dialect scala3 --scalafmt-version 3.5.8

Either of those (or both) can be skipped, which will make Scala CLI infer a default value.

The configuration used can be saved in the workspace by passing the --save-scalafmt-conf option.

Added in #1192 by wleczny

Define output option for package command with using directives​

It is now possible to pass the output option of the package command with using directives instead of passing it directly from bash.

Added in #1213 by wleczny

Add support for running multiple snippets of the same kind​

Scala CLI now allows to pass multiple snippets of the same kind.

It was previously possible to mix different kinds (so to pass a Java snippet alongside a Scala one), but not for example 2 separate Scala snippets. That limitation no longer applies.

When passed this way, each snippet is then treated as a separate input by Scala CLI.

$ scala-cli --scala-snippet '@main def main() = println(Messages.hello)' --scala-snippet 'object Messages { def hello = "Hello" }'
Hello

Added in #1182 by Gedochao

Add bloop sub-command​

Scala CLI now has a (hidden for now) bloop sub-command, that runs a command using the Scala CLI Bloop server (while the mainline Bloop bloop CLI uses its default Bloop server). This is handy when debugging things on Scala CLI for example, allowing one to manually run scala-cli bloop projects or scala-cli bloop compile.

Added in #1199 by alexarchambault

Make main class optional in preamble-less assemblies​

It is now allowed to generate an assembly, even for code that has no main class, when --preamble=false is passed. This can be useful for libraries, if users want to pass the assembly to tools such as proguard. This also accepts a (hidden) --main-class-in-manifest=false option if users want not only no preamble, but also no mention of main class in the assembly manifest (META-INF/MANIFEST.MF in the assembly JAR). The latter option is useful for tools, such as the hadoop jar command, that behave differently depending on the presence or not of a main class in the manifest.

Added in #1200 by alexarchambault

Important fixes & enhancements​

Prevent erroneous using directives from blocking the initial run of BSP​

Up till now, running the setup-ide sub-command on sources containing using directives with syntax errors or pointing to dependencies which could not be fetched would create a BSP setup which could not be imported correctly by IDEs. This is no longer the case and such a BSP connection should now import correctly, so that it's possible to fix the faulty code within the comfort of one's IDE of choice.

This fixes #1097

Added in #1195 by Gedochao

Work in progress​

Allow to globally turn actionable diagnostics on or off​

It is now possible to globally enable or disable actionable diagnostics using the config sub-command.

The relevant configuration is under the actions key.

$ scala-cli config actions true

Added in #1193 by lwronski

Other changes​

Documentation​

Build and internal changes​

Updates​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.10...v0.1.11

v0.1.10​

Initial support for importing other sources via using directives​

It is now possible to add sources to a Scala CLI project from a source file, with using file directives:

//> using file "Other.scala"
//> using file "extra/"

Note that several sources can be specified in a single directive

//> using file "Other.scala" "extra/"

Added in #1157 by lwronski.

Add dependency update sub-command​

Scala CLI can now update dependencies in user projects, using the dependency-update sub-command, like

scala-cli dependency-update --all .

When updates are available, this sub-command asks whether to update each of those, right where these dependencies are defined.

Added in #1055 by lwronski.

Running snippets passed as arguments​

Scala CLI can now run Scala or Java code passed on the command-line, via -e / --script-snippet / --scala-snippet / --java-snippet:

$ scala-cli -e 'println("Hello")'
Hello

$ scala-cli --script-snippet 'println("Hello")'
Hello

$ scala-cli --scala-snippet '@main def run() = println("Hello")' 
Hello

$ scala-cli --java-snippet 'public class Main { public static void main(String[] args) { System.out.println("Hello"); } }'
Hello

These options are meant to be substitutes to the -e option of the scala script that ships in scalac archives.

Added in #1166 by Gedochao.

Uninstall instructions and uninstall sub-command​

Uninstalling Scala CLI is now documented in the main installation page, right after the installation instructions. In particular, when installed via the installation script, Scala CLI can be uninstalled via a newly added uninstall sub-command.

Added in #1122 and #1152 by wleczny.

Important fixes & enhancements​

ES modules​

Scala CLI now supports the ES Scala.js module kind, that can be enabled via a //> using jsModuleKind "esmodule" directive, allowing to import other ES modules in particular.

Added in #1142 by hugo-vrijswijk.

Putting Java options in assemblies, launchers, and docker images, in package sub-command​

Passing --java-opt and --java-prop options to the package sub-command is now allowed. The passed options are hard-coded in the generated assemblies or launchers, and in docker images.

Added in #1167 by wleczny.

--command and --scratch-dir options in run sub-command​

The run sub-command can now print the command it would have run, rather than running it. This can be useful for debugging purposes, or if users want to manually tweak commands right before they are run. Pass --command to run to enable it. This prints one argument per line, for easier automated processing:

$ scala-cli run --command -e 'println("Hello")' --runner=false
~/Library/Caches/Coursier/arc/https/github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.2%252B8/OpenJDK17U-jdk_x64_mac_hotspot_17.0.2_8.tar.gz/jdk-17.0.2+8/Contents/Home/bin/java
-cp
~/Library/Caches/ScalaCli/virtual-projects/ee/project-3c6fdea1/.scala-build/project_ed4bea6d06_ed4bea6d06/classes/main:~/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala3-library_3/3.1.3/scala3-library_3-3.1.3.jar:~/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.8/scala-library-2.13.8.jar
snippet_sc

When run relies on temporary files (when Scala.js is used for example), one can pass a temporary directory via --scratch-dir, so that temporary files are kept even when scala-cli doesn't run anymore:

$ scala-cli run --command -e 'println("Hello")' --js --runner=false --scratch-dir ./tmp
node
./tmp/main1690571004533525773.js

Added in #1163 by by alexarchambault.

Don't put Scala CLI internal modules in packages​

Scala CLI doesn't put anymore its stubs module and its "runner" module in generated packages, in the package sub-command.

Fixed in #1161 by alexarchambault.

Don't write preambles in generated assemblies in the package sub-command​

Passing --preamble=false to scala-cli package --assembly makes it generate assemblies without a shell preamble. As a consequence, these assemblies cannot be made executable, but these look more like "standard" JARs, which is required in some contexts.

Fixed in #1161 by alexarchambault.

Don't put some dependencies in generated assemblies in the package sub-command​

Some dependencies, alongside all their transitive dependencies, can be excluded from the generated assemblies. Pass --provided org:name to scala-cli package --assembly to remove a dependency, like

$ scala-cli package SparkJob.scala --assembly --provided org.apache.spark::spark-sql

Note that unlike "provided" dependencies in sbt, and compile-time dependencies in Mill, all transitive dependencies are excluded from the assembly. In the Spark example above, for example, as spark-sql depends on scala-library (the Scala standard library), the latter gets excluded from the assembly too (which works fine in the context of Spark jobs).

Fixed in #1161 by alexarchambault.

In progress​

Experimental Spark capabilities​

The package sub-command now accepts a --spark option, to generate assemblies for Spark jobs, ready to be passed to spark-submit. This option is hidden (not printed in scala-cli package --help, only in --help-full), and should be considered experimental.

See this document for more details about these experimental Spark features.

Added in #1086 by alexarchambault.

Other changes​

Documentation​

Build and internal changes​

Updates​

New Contributors​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.9...v0.1.10

v0.1.9​

--list-main-classes for publish & package​

publish and package sub-commands now support the --list-main-classes option, which allows to list all the available main classes. Previously it was only available in the run command.

Added in #1118 by Gedochao

Important fixes & enhancements​

fmt options improvement​

Added missing documentation on how to pass native scalafmt options in the fmt sub-command with the -F option.

$ scala-cli fmt -F --version
scalafmt 3.5.2

Additionally, a couple of scalafmt's native options received aliases in Scala CLI:

--respect-project-filters is an alias for -F --respect-project-filters. Because of the way sources are passed by Scala CLI to scalafmt under the hood, we now turn it on by default to respect any project.excludePaths settings in the user's .scalafmt.conf.
It can be disabled by passing --respect-project-filters=false to revert to previous behaviour. This addresses #1121

--scalafmt-help is an alias for -F --help. It shows the --help output from scalafmt, which might prove as helpful reference when in need of using native scalafmt options with -F.

Added in #1135 by Gedochao

Include libsodium.dll on Windows​

Static linking of libsodium in Windows launcher has been fixed. This addresses #1114

Added in #1115 by alexarchambault

Force interactive mode for update command​

Interactive mode for update sub-command is now enabled by default.

Added in #1100 by lwronski

In progress​

Better BSP support for Scala scripts​

Other changes​

Documentation PRs​

Build and internal changes​

Updates​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.8...v0.1.9

v0.1.8​

--list-main-classes option for the run command​

You can pass the option --list-main-classes to the run command to list all the available main classes, including scripts.

$ scala-cli . --list-main-classes
Hello scripts.AnotherScript_sc scripts.Script_sc

Added in #1095 by Gedochao

Add config command​

The config sub-command allows to get and set various configuration values, intended for use by other Scala CLI sub-commands.

This feature has been added in preparation for the publish command, stay tuned for future announcements.

Added in #1056 by alexarchambault

Prioritise non-script main classes​

When trying to run a directory containing scripts and just a single non-script main class, the non-script main class will now be prioritised and run by default.

$ scala-cli .
Running Hello. Also detected script main classes: scripts.AnotherScript_sc, scripts.Script_sc
You can run any one of them by passing option --main-class, i.e. --main-class scripts.AnotherScript_sc
All available main classes can always be listed by passing option --list-main-classes
Hello world

Changed in #1095 by Gedochao

Important bugfixes​

Accept latest Scala versions despite stale Scala version listings in cache​

Scala CLI uses version listings from Maven Central to check if a Scala version is valid. When new Scala versions are released, users could sometimes have stale version listings in their Coursier cache for a short period of time (the Coursier cache TTL, which is 24 hours by default). This prevented these users to use new Scala versions during that time. To work around that, Scala CLI now tries to re-download version listings when they don't have the requested Scala version. This addresses #1090

Fixed in #1096 by lwronski

Bloop now uses JAVA_HOME by default​

Bloop should now pick up the JDK available in JAVA_HOME. It was formerly necessary to pass --bloop-jvm system explicitly. This addresses #1102

Fixed in #1084 by lwronski

The -coverage-out option now accepts relative paths​

Scala CLI now correctly processes relative paths when passed to the -coverage-out option. Formerly, the scoverage.coverage file would not be properly generated when a relative path was passed. This addresses #1072

Fixed in #1080 by lwronski

Other changes​

Documentation PRs​

Fixes​

  • Add suffix to project name which contains virtual files by lwronski in #1070

Build and internal changes​

Full Changelog: https://github.com/VirtusLab/scala-cli/compare/v0.1.7...v0.1.8

Older versions​

The release notes for all the past versions of Scala CLI can be viewed on our releases page on GitHub.