feat: support for node worker (#51)

node.d.ts

@@ -0,0 +1,5 @@
+// node worker
+declare module '*?nodeWorker' {
+  import { Worker, WorkerOptions } from 'node:worker_threads'
+  export default function (options: WorkerOptions): Worker
+}

package.json

@@ -9,7 +9,8 @@
   },
   "files": [
     "bin",
-    "dist"
+    "dist",
+    "node.d.ts"
   ],
   "engines": {
     "node": ">=12.2.0"
@@ -83,6 +84,7 @@
     "@babel/plugin-transform-arrow-functions": "^7.18.6",
     "cac": "^6.7.14",
     "esbuild": "^0.15.12",
+    "magic-string": "^0.26.7",
     "picocolors": "^1.0.0"
   }
 }

pnpm-lock.yaml

@@ -17,6 +17,7 @@ specifiers:
   eslint-plugin-prettier: ^4.2.1
   fs-extra: ^10.1.0
   lint-staged: ^13.0.3
+  magic-string: ^0.26.7
   picocolors: ^1.0.0
   prettier: ^2.7.1
   rollup: ^2.79.1
@@ -30,6 +31,7 @@ dependencies:
   '@babel/plugin-transform-arrow-functions': 7.18.6_@babel+core@7.19.6
   cac: 6.7.14
   esbuild: 0.15.12
+  magic-string: 0.26.7
   picocolors: 1.0.0
 
 devDependencies:
@@ -1916,6 +1918,13 @@ packages:
       yallist: 4.0.0
     dev: true
 
+  /magic-string/0.26.7:
+    resolution: {integrity: sha512-hX9XH3ziStPoPhJxLq1syWuZMxbDvGNbVchfrdCtanC7D13888bMFow61x8axrx+GfHLtVeAx2kxL7tTGRl+Ow==}
+    engines: {node: '>=12'}
+    dependencies:
+      sourcemap-codec: 1.4.8
+    dev: false
+
   /merge-stream/2.0.0:
     resolution: {integrity: sha512-abv/qOcuPfk3URPfDzmZU1LKmuw8kT+0nIHvKrKgFrwifol/doWcdA4ZqsWQ8ENrFKkd67Mfpo/LovbIUsbt3w==}
     dev: true
@@ -2277,6 +2286,10 @@ packages:
     engines: {node: '>=0.10.0'}
     dev: true
 
+  /sourcemap-codec/1.4.8:
+    resolution: {integrity: sha512-9NykojV5Uih4lgo5So5dtw+f0JgJX30KCNI8gwhz2J9A15wD0Ml6tjHKwf6fTSa6fAdVBdZeNOs9eJ71qCk8vA==}
+    dev: false
+
   /sprintf-js/1.0.3:
     resolution: {integrity: sha512-D9cPgkvLlV3t3IzL0D0YLvGA9Ahk4PcvVwUbN0dSGr1aP0Nrt4AEnTUbuGvquEC0mA64Gqt1fzirlRs5ibXx8g==}
     dev: true

src/config.ts

@@ -16,6 +16,7 @@ import {
 import { build } from 'esbuild'
 
 import { electronMainVitePlugin, electronPreloadVitePlugin, electronRendererVitePlugin } from './plugin'
+import workerPlugin from './plugins/worker'
 import { isObject, dynamicImport } from './utils'
 
 export { defineConfig as defineViteConfig } from 'vite'
@@ -129,7 +130,7 @@ export async function resolveConfig(
           resetOutDir(mainViteConfig, outDir, 'main')
         }
 
-        mergePlugins(mainViteConfig, electronMainVitePlugin({ root }))
+        mergePlugins(mainViteConfig, [...electronMainVitePlugin({ root }), workerPlugin()])
 
         loadResult.config.main = mainViteConfig
         loadResult.config.main.configFile = false

src/plugins/worker.ts

@@ -0,0 +1,69 @@
+import path from 'node:path'
+import type { Plugin } from 'vite'
+import type { SourceMapInput } from 'rollup'
+import MagicString from 'magic-string'
+import { cleanUrl, parseRequest } from '../utils'
+
+const nodeWorkerAssetUrlRE = /__VITE_NODE_WORKER_ASSET__([a-z\d]{8})__/g
+
+/**
+ * Resolve `?nodeWorker` import and automatically generate `Worker` wrapper.
+ */
+export default function workerPlugin(): Plugin {
+  let sourcemap: boolean | 'inline' | 'hidden' = false
+  return {
+    name: 'vite:node-worker',
+    apply: 'build',
+    enforce: 'pre',
+    configResolved(config): void {
+      sourcemap = config.build.sourcemap
+    },
+    resolveId(id, importer): string | void {
+      const query = parseRequest(id)
+      if (query && typeof query.nodeWorker === 'string') {
+        return id + `&importer=${importer}`
+      }
+    },
+    load(id): string | void {
+      const query = parseRequest(id)
+      if (query && typeof query.nodeWorker === 'string' && typeof query.importer === 'string') {
+        const cleanPath = cleanUrl(id)
+        const hash = this.emitFile({
+          type: 'chunk',
+          id: cleanPath,
+          importer: query.importer
+        })
+        const assetRefId = `__VITE_NODE_WORKER_ASSET__${hash}__`
+        return `
+        import { Worker } from 'node:worker_threads';
+        export default function (options) { return new Worker(require.resolve(${assetRefId}), options); }`
+      }
+    },
+    renderChunk(code, chunk): { code: string; map: SourceMapInput } | null {
+      if (code.match(nodeWorkerAssetUrlRE)) {
+        let match: RegExpExecArray | null
+        const s = new MagicString(code)
+
+        while ((match = nodeWorkerAssetUrlRE.exec(code))) {
+          const [full, hash] = match
+          const filename = this.getFileName(hash)
+          let outputFilepath = path.posix.relative(path.dirname(chunk.fileName), filename)
+          if (!outputFilepath.startsWith('.')) {
+            outputFilepath = './' + outputFilepath
+          }
+          const replacement = JSON.stringify(outputFilepath)
+          s.overwrite(match.index, match.index + full.length, replacement, {
+            contentOnly: true
+          })
+        }
+
+        return {
+          code: s.toString(),
+          map: sourcemap ? s.generateMap({ hires: true }) : null
+        }
+      }
+
+      return null
+    }
+  }
+}

src/utils.ts

@@ -1,3 +1,5 @@
+import { URL, URLSearchParams } from 'node:url'
+
 export function isObject(value: unknown): value is Record<string, unknown> {
   return Object.prototype.toString.call(value) === '[object Object]'
 }
@@ -9,3 +11,16 @@ export const wildcardHosts = new Set(['0.0.0.0', '::', '0000:0000:0000:0000:0000
 export function resolveHostname(optionsHost: string | boolean | undefined): string {
   return typeof optionsHost === 'string' && !wildcardHosts.has(optionsHost) ? optionsHost : 'localhost'
 }
+
+export const queryRE = /\?.*$/s
+export const hashRE = /#.*$/s
+
+export const cleanUrl = (url: string): string => url.replace(hashRE, '').replace(queryRE, '')
+
+export function parseRequest(id: string): Record<string, string> | null {
+  const { search } = new URL(id, 'file:')
+  if (!search) {
+    return null
+  }
+  return Object.fromEntries(new URLSearchParams(search))
+}