scala-wasm

This is a friendly fork of Scala.js, targeting stand-alone Wasm runtimes such as wasmtime, leveraging WASIp2 and Wasm Component Model.

Getting Started

scala-wasm is available as 1.21.1-wasm.4.

In project/plugins.sbt:

addSbtPlugin("io.github.scala-wasm" % "sbt-scalajs" % "1.21.1-wasm.4")

Prerequisites

• wasm-tools
• wasmtime
• wit-bindgen-scala:

cargo install wit-bindgen-scala --version 0.1.0-rc.1

• (optional) wkg
  • Required if you want to add Wasm Component Model dependencies.
• (optional) Required for running test-component-model:
  • wac
  • Setting up Rust
  • cargo component
    • cargo component >= 0.18.0 may not work(?)

Examples

• helloworld-wasi
• helloworld-component-model
• echo-server
• scala-wasm Spin templates

Test

test-suite

sbt:Scala.js> set Global/enableWasmEverywhere := true
sbt:Scala.js> set scalaJSLinkerConfig in testSuite.v2_12 ~= (_.withModuleKind(ModuleKind.MinimalWasmModule))
sbt:Scala.js> testSuite2_12/test

Tests that do not link in pure Wasm are filtered out from unmanagedSourceDirectories and sources, see testSuiteCommonSettings.

test-component-model

Test suites for Wasm Component Model based interop.

Build Wasm Component from Scala.

$ sbt
sbt:Scala.js> set Global/enableWasmEverywhere := true
sbt:Scala.js> testComponentModel2_12/fastLinkJS

Build Wasm Components from Rust.

$ cd examples/test-component-model/rust-exports
$ cargo component build --target wasm32-wasip2 -r

$ cd examples/test-component-model/rust-run
$ cargo component build --target wasm32-wasip2 -r

Compose Wasm Components and run.

$ cd examples/test-component-model
$ make run SCALA_VERSION=2.12

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What follows below is README.md of the upstream scala-js project

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Scala.js

Chat: #scala-js on Discord.

This is the repository for Scala.js, the Scala to JavaScript compiler.

• Report an issue
• Developer documentation
• Contributing guidelines

License

Scala.js is distributed under the Apache License Version 2.0.