Very important notice about the Javalib
Scala.js contains a reimplementation of part of the JDK in Scala.js itself.
To contribute to this code, it is strictly forbidden to even look at the source code of the Oracle JDK or OpenJDK!
This is for license considerations: these JDKs are under a GPL-based license, which is not compatible with our BSD 3-clause license.
It is also recommended not to look at any other JDK implementation (such as Apache Harmony), to minimize the chance of copyright debate.
The first time, or in the rare events where
you need to run
$ npm install
from your shell. If you really do not want to do this, you can avoid that
step, but you will need to use
set MyScalaJSPlugin.wantSourceMaps in testSuite := false within sbt to
by-pass source-map-related tests. In addition, bootstrap tests will not pass.
Otherwise, everything happens within sbt.
Run the normal test suite using the entire Scala.js toolchain using
In order to test the tests themselves, run the cross-compiling tests on the JVM with:
If you have changed the IR or the compiler, you typically need to
before testing anew.
If you have changed the IR, the linker, the JS environments, the test adapter or the sbt plugin, you typically need to
To test in fullOpt stage:
> set scalaJSStage in Global := FullOptStage
There are also a few additional tests in a separate testing project:
The compiler tests (mostly verifying expected compile error messages) can be run with
The full partest suite (tests of the Scala language, ported in Scala.js) are run with:
or, more typically,
> partestSuite/testOnly -- --fastOpt
The JUnit tests from scala/scala can be run with
If you want to develop in Eclipse, use sbteclipse. Projects as created by the build by default are not suited for Eclipse. You can create somewhat appropriate projects with:
$ GENERATING_ECLIPSE=true sbt "eclipse with-source=true"
You will still have to fix a few things:
- Uncheck the "Allow output directories per source directory" in Build path
- Add transitive project dependencies in Build path
Organization of the repository
The repository is organized as follows:
ir/The Intermediate Representation, produced by the compiler and consumed by the linker
compiler/The scalac compiler plugin
io/Virtual I/O abstractions
logging/A tiny logging API
linker/The linker, optimizer, verifier, etc.: everything that happens at link time
library/The Scala.js standard library (everything inside
javalanglib/Implementation in Scala.js of the classes in
javalib/Implementation in Scala.js of other classes in
scalalib/Almost void project for recompiling the Scala library for Scala.js
library-aux/A few files of the Scala library that need to be compiled separately
All of these are packaged in
nodejs-env/The Node.js environment
Other JS environments are developed in separate repositories under the
There is a generic infrastructure that maps the sbt-testing-interface API across the JVM/JS boundary, so that Scala.js testing frameworks can be piloted from JVM processes such as sbt.
test-interface/JS side of the bridge, as well as the JS definition of the sbt-testing-interface API
test-adapter/JVM side of the bridge
This repository also contains a specific implementation of JUnit:
junit-runtime/The run-time library for JUnit
junit-plugin/The JUnit compiler plugin
sbt-plugin/The sbt plugin itself
test-suite/The main test suite of Scala.js
partest-suite/The partest suite of Scala
scala-test-suite/The JUnit suite of Scala
examples/helloworld/A simple Hello World, typically used as sandbox for quick testing
examples/reversi/The historical Reversi demo - we use it to track the impact of changes on the emitted code size
examples/testing/A simple project with tests using the DOM, mostly used to test
testHtmlwith DOM interaction
The helloworld and reversi also have HTML pages to run them in real browsers.
The build itself
The build itself contains the entire sbt plugin (and all its dependencies) as
part of its sources.
If you change any of the IR, virtual IO, logging API, linker, JS environments,
test adapter, or the sbt plugin itself, chances are you need to
build for your changes to take effect.
To publish your changes locally to be used in a separate project, use the
SCALA_VERSION refers to the Scala version used by the separate project.
> ++SCALA_VERSION > ;compiler/publishLocal;library/publishLocal;testInterface/publishLocal;jUnitRuntime/publishLocal;jUnitPlugin/publishLocal > ++2.10.7 > ;ir/publishLocal;io/publishLocal;logging/publishLocal;linker/publishLocal;jsEnvs/publishLocal;jsEnvsTestKit/publishLocal;nodeJSEnv/publishLocal;testAdapter/publishLocal;sbtPlugin/publishLocal