README.md

Experimental Scala.js linker backend for WasmGC

Usage

• first, npm install
• then sample/run to compile sample/src/main/scala/Sample.scala.
  • prints the WebAssembly Text Format (WAT) (Stack IR form) to the console, for debugging
  • writes the binary format (WASM) to target/output.wasm

Run the binary using through run.js using a JavaScript engine that supports WasmGC, such as Deno

$ deno run --allow-read run.mjs

Debugging tools

• The WasmGC reference interpreter can be used to validate and convert between the binary and text form:
  • https://github.com/WebAssembly/gc/tree/main/interpreter
  • Use docker image for it https://github.com/tanishiking/wasmgc-docker

Testing

Requires NodeJS >= 22 (for enough support of WasmGC).

$ NVM_NODEJS_ORG_MIRROR=https://nodejs.org/download/nightly nvm install v22

• tests/test will
  • Run testSuite/run to compile the Scala code under test-suite to WebAssembly
  • Run the WebAssembly binary using NodeJS
• Each Scala program in test-suite should have a function that has no arguments and return a Boolean value. The test passes if the function returns true.
• When you add a test,
  • Add a file under test-suite
  • Add a test case to cli/src/main/scala/TestSuites.scala (methodName should be a exported function name).