Scala Plugin for IntelliJ IDEA

Plugin that implements Scala, sbt, Play 2, SSP and Hocon support in IntelliJ IDEA.

General information

• To get information about how to install and use this plugin in IDEA, please use IntelliJ IDEA online help.

• If you have any question about the Scala plugin, we'd be glad to answer it in our developer community.

• If you found a bug, please report it on our issue tracker.

• If you want to contribute, please see our intro to the Scala plugin internals.

Setting up the project

In order to take part in Scala plugin development, you need to:

1. Install IntelliJ IDEA 2017.1 or higher with a compatible version of Scala plugin

2. Fork this repository and clone it to your computer

$ git clone https://github.com/JetBrains/intellij-scala.git

3. Open IntelliJ IDEA, select File -> New -> Project from existing sources, point to the directory where Scala plugin repository is and then import it as sbt project.

4. When importing is finished, in order to get artifacts and run configurations for IDEA project, go to the Scala plugin repo directory and run

$ git checkout .idea

5. Open the sbt options (Preferences -> Build, Execution, Deployment -> sbt)

• select Use sbt shell for build and import
• in Global sbt settings -> JVM Options -> Maximum heap size, enter at least 2048

6. Select the IDEA run configuration and select the Run or Debug button to build and start a development version of IDEA with the Scala plugin.

Browsing IntelliJ platform sources

When loading the plugin in sbt, the IntelliJ platform is downloaded to <home>/.ScalaPluginIC/sdk/<sdk version>/. When opening a platform API class you will see the option to "attach sources". Click it, navigate to the sdk directory and select sources.zip, then choose "All".

Tests

To run tests properly, the plugin needs to be packaged. On the sbt shell:

1. packagePluginCommunity
2. runFastTests

The "fast tests" can take over an hour. To get a quick feedback on project health, run the "typeInference tests"

> testOnly org.jetbrains.plugins.scala.lang.typeInference.*

Travis CI

The project is configured to build and run the typeInference tests with Travis CI, which you can enable in your forks. The full test suite can't currently be run because Travis doesn't allow builds to take that long.

Running the plugin

Debugging mode

The easiest way to try your changes is typically to launch the IDEA run configuration which is created when you set up the project as described above.

As a standalone plugin

To run and distribute a modified version of the plugin in a regular IntelliJ instance, you need to package it.

1. on the sbt shell, run packagePluginZip. This will output the generated plugin zip location (typically into <project directory>/target/scala-plugin.zip).
2. In IntelliJ, open Preferences, section Plugins, choose "Install plugin from disk..." and navigate to the scala-plugin.zip
3. Restart IntelliJ