scala-wasm

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

Prequirements

• wasm-tools
• wasmtime
• (optional) wkg
  • Required if you wanna 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

• echo-server

Test

test-suite

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

Tests don't 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 Compoennt from Scala.

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

$ cd examples/test-component-model
$ wasm-tools component embed wit .2.12/target/scala-2.12/testing-module-for-component-model-fastopt/main.wasm -o main.wasm -w scala --encoding utf16
$ wasm-tools component new main.wasm -o main.wasm

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.

$ wac plug --plug rust-exports/target/wasm32-wasip1/release/rust_exports.wasm main.wasm -o scala.wasm
$ wac plug --plug scala.wasm rust-run/target/wasm32-wasip1/release/rust_run.wasm -o out.wasm

$ wasmtime -W function-references,gc -C collector=null out.wasm

Once we implement wit-bindgen for us, this tests should migrate to https://github.com/bytecodealliance/wit-bindgen

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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.