vitest/packages/web-worker/src/utils.ts

/* eslint-disable no-restricted-imports */
import type { WorkerGlobalState } from 'vitest'
import ponyfillStructuredClone from '@ungap/structured-clone'
import createDebug from 'debug'
import type { CloneOption } from './types'

export const debug = createDebug('vitest:web-worker')

export function getWorkerState(): WorkerGlobalState {
  // @ts-expect-error untyped global
  return globalThis.__vitest_worker__
}

export function assertGlobalExists(name: string) {
  if (!(name in globalThis))
    throw new Error(`[@vitest/web-worker] Cannot initiate a custom Web Worker. "${name}" is not supported in this environment. Please, consider using jsdom or happy-dom environment.`)
}

function createClonedMessageEvent(data: any, transferOrOptions: StructuredSerializeOptions | Transferable[] | undefined, clone: CloneOption) {
  const transfer = Array.isArray(transferOrOptions) ? transferOrOptions : transferOrOptions?.transfer

  debug('clone worker message %o', data)
  const origin = typeof location === 'undefined' ? undefined : location.origin

  if (typeof structuredClone === 'function' && clone === 'native') {
    debug('create message event, using native structured clone')
    return new MessageEvent('message', {
      data: structuredClone(data, { transfer }),
      origin,
    })
  }
  if (clone !== 'none') {
    debug('create message event, using polyfilled structured clone')
    transfer?.length && console.warn(
      '[@vitest/web-worker] `structuredClone` is not supported in this environment. '
      + 'Falling back to polyfill, your transferable options will be lost. '
      + 'Set `VITEST_WEB_WORKER_CLONE` environmental variable to "none", if you don\'t want to loose it,'
      + 'or update to Node 17+.',
    )
    return new MessageEvent('message', {
      data: ponyfillStructuredClone(data, { lossy: true }),
      origin,
    })
  }
  debug('create message event without cloning an object')
  return new MessageEvent('message', {
    data,
    origin,
  })
}

export function createMessageEvent(data: any, transferOrOptions: StructuredSerializeOptions | Transferable[] | undefined, clone: CloneOption) {
  try {
    return createClonedMessageEvent(data, transferOrOptions, clone)
  }
  catch (error) {
    debug('failed to clone message, dispatch "messageerror" event: %o', error)
    return new MessageEvent('messageerror', {
      data: error,
    })
  }
}

export function getRunnerOptions() {
  const { config, rpc, mockMap, moduleCache } = getWorkerState()

  return {
    fetchModule(id: string) {
      return rpc.fetch(id)
    },
    resolveId(id: string, importer?: string) {
      return rpc.resolveId(id, importer)
    },
    moduleCache,
    mockMap,
    interopDefault: config.deps.interopDefault ?? true,
    root: config.root,
    base: config.base,
  }
}