feat: add support for node >=16.12.0

loader.mjs

@@ -5,14 +5,37 @@ import { transformSync } from 'esbuild'
 const baseURL = pathToFileURL(`${process.cwd()}/`).href
 const isWindows = process.platform === 'win32'
 
-const extensionsRegex = /\.(tsx?|json)$/;
+const extensionsRegex = /\.(tsx?|json)$/
 const excludeRegex = /^\w+:/
 
+function esbuildTransformSync(rawSource, filename, url, format) {
+  const {
+    code: js,
+    warnings,
+    map: jsSourceMap,
+  } = transformSync(rawSource.toString(), {
+    sourcefile: filename,
+    sourcemap: 'both',
+    loader: new URL(url).pathname.match(extensionsRegex)[1],
+    target: `node${process.versions.node}`,
+    format: format === 'module' ? 'esm' : 'cjs',
+  })
+
+  if (warnings && warnings.length > 0) {
+    for (const warning of warnings) {
+      console.warn(warning.location)
+      console.warn(warning.text)
+    }
+  }
+
+  return { js, jsSourceMap }
+}
+
 export function resolve(specifier, context, defaultResolve) {
   const { parentURL = baseURL } = context
   const url = new URL(specifier, parentURL)
   if (extensionsRegex.test(url.pathname))
-    return { url: url.href }
+    return { url: url.href, format: 'module' }
 
   // ignore `data:` and `node:` prefix etc.
   if (!excludeRegex.test(specifier)) {
@@ -22,14 +45,39 @@ export function resolve(specifier, context, defaultResolve) {
       url.pathname = `${pathname}.${ext}`
       const path = fileURLToPath(url.href)
       if (fs.existsSync(path))
-        return { url: url.href }
+        return {
+          url: url.href,
+          format: extensionsRegex.test(url.pathname) && 'module',
+        }
     }
   }
 
   // Let Node.js handle all other specifiers.
   return defaultResolve(specifier, context, defaultResolve)
 }
 
+// New hook starting from Node v16.12.0
+// See: https://github.com/nodejs/node/pull/37468
+export function load(url, context, defaultLoad) {
+  if (extensionsRegex.test(new URL(url).pathname)) {
+    const { format } = context
+
+    let filename = url
+    if (!isWindows) filename = fileURLToPath(url)
+
+    const rawSource = fs.readFileSync(new URL(url), { encoding: 'utf8' })
+    const { js } = esbuildTransformSync(rawSource, filename, url, format)
+
+    return {
+      format: 'module',
+      source: js,
+    }
+  }
+
+  // Let Node.js handle all other format / sources.
+  return defaultLoad(url, context, defaultLoad)
+}
+
 export function getFormat(url, context, defaultGetFormat) {
   if (extensionsRegex.test(new URL(url).pathname)) {
     return {
@@ -46,23 +94,9 @@ export function transformSource(source, context, defaultTransformSource) {
 
   if (extensionsRegex.test(new URL(url).pathname)) {
     let filename = url
-    if (!isWindows)
-      filename = fileURLToPath(url)
-
-    const { code: js, warnings, map: jsSourceMap } = transformSync(source.toString(), {
-      sourcefile: filename,
-      sourcemap: 'both',
-      loader: new URL(url).pathname.match(extensionsRegex)[1],
-      target: `node${process.versions.node}`,
-      format: format === 'module' ? 'esm' : 'cjs',
-    })
-
-    if (warnings && warnings.length > 0) {
-      for (const warning of warnings) {
-        console.warn(warning.location)
-        console.warn(warning.text)
-      }
-    }
+    if (!isWindows) filename = fileURLToPath(url)
+
+    const { js } = esbuildTransformSync(source, filename, url, format)
 
     return {
       source: js,