napi-rs/examples/napi/__tests__/worker.cjs

const { parentPort } = require('worker_threads')

const isWasiTest = !!process.env.WASI_TEST

import('../index.js')
  .then(({ default: native }) => {
    parentPort.on('message', ({ type }) => {
      switch (type) {
        case 'require':
          parentPort.postMessage(
            native.Animal.withKind(native.Kind.Cat).whoami() +
              native.DEFAULT_COST,
          )
          break
        case 'async:buffer':
          Promise.all(
            Array.from({ length: isWasiTest ? 2 : 100 }).map(() =>
              native.bufferPassThrough(Buffer.from([1, 2, 3])),
            ),
          )
            .then(() => {
              parentPort.postMessage('done')
            })
            .catch((e) => {
              throw e
            })
          break
        case 'async:arraybuffer':
          Promise.all(
            Array.from({ length: isWasiTest ? 2 : 100 }).map(() =>
              native.arrayBufferPassThrough(Uint8Array.from([1, 2, 3])),
            ),
          )
            .then(() => {
              parentPort.postMessage('done')
            })
            .catch((e) => {
              throw e
            })

          break
        case 'constructor':
          let ellie
          for (let i = 0; i < (isWasiTest ? 10 : 10000); i++) {
            ellie = new native.Animal(native.Kind.Cat, 'Ellie')
          }
          parentPort.postMessage(ellie.name)
          break
        default:
          throw new TypeError(`Unknown message type: ${type}`)
      }
    })
  })
  .catch((e) => {
    console.error(e)
    process.exit(1)
  })