harness/wazero

Go host implementation via Node-API addon.

Purpose

Proves the ABI is not tied to one runtime language by implementing the same shared contract with a native addon.

Artifact

• dist/wazero.node (target-specific native addon)

Responsibilities

• compile and instantiate Wasm via wazero
• mirror JS host wire decoding and callback registration
• expose callI32, discover, run
• run shared start() through harness/shared/start.cjs with same-machine worker slots for ready work
• provide persistent coverage snapshots (getCoverageSnapshot / resetCoverage)
• decode and surface structured debug events for rewritten abort(...) / trace(...) payloads
• provide host-owned fixture reads plus snapshot compare/update support for bundled uvu/assert
• explicit close() to release native resources promptly

Build Requirements

• Go 1.26.1 or newer toolchain
• Node headers
• Windows node.lib (auto-download path supported)

Build / Install

cd harness/wazero
npm run build
npm test

Packaging Notes

• published as @as-harness/wazero plus per-platform optional binary packages
• Linux glibc is in scope for the current public npm lane; musl is not.
• source worker execution under Bun on Windows stages a private copy of wazero.node before loading the addon.
• source-host CLI smoke proof builds a Node-targeted CLI bundle and runs that bundle under Node 25.8.1 instead of invoking bun run ./cli/index.ts directly.
• source Linux arm64 and Windows builds can be produced locally.
• source-host verification and npm package install-smoke are now the maintained proof paths.

Related Docs

• docs/003-2026-03-17-harness-abi.md
• docs/007-2026-03-17-host-runner-contract.md
• docs/022-2026-03-23-abort-trace-debug-payload-contract.md