feat: add support for node >=16.12.0

loader.mjs

@@ -1,18 +1,46 @@
 import { URL, pathToFileURL, fileURLToPath } from 'url'
 import fs from 'fs'
 import { transformSync } from 'esbuild'
+import semverGte from 'semver/functions/gte.js'
 
 const baseURL = pathToFileURL(`${process.cwd()}/`).href
 const isWindows = process.platform === 'win32'
 
-const extensionsRegex = /\.(tsx?|json)$/;
+const extensionsRegex = /\.(tsx?|json)$/
 const excludeRegex = /^\w+:/
 
+// Node v16.12.0 has breaking changes for the loader hooks
+// See: https://github.com/nodejs/node/pull/37468
+const HAS_UPDATED_HOOKS = semverGte(process.versions.node, '16.12.0')
+
+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)) {
@@ -22,53 +50,66 @@ 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)
 }
 
-export function getFormat(url, context, defaultGetFormat) {
+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 URLs.
-  return defaultGetFormat(url, context, defaultGetFormat)
+  // Let Node.js handle all other format / sources.
+  return defaultLoad(url, context, defaultLoad)
 }
 
-export function transformSource(source, context, defaultTransformSource) {
-  const { url, format } = context
-
-  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)
+export const getFormat = HAS_UPDATED_HOOKS
+  ? undefined
+  : (url, context, defaultGetFormat) => {
+      if (extensionsRegex.test(new URL(url).pathname)) {
+        return {
+          format: 'module',
+        }
       }
-    }
 
-    return {
-      source: js,
+      // Let Node.js handle all other URLs.
+      return defaultGetFormat(url, context, defaultGetFormat)
     }
-  }
 
-  // Let Node.js handle all other sources.
-  return defaultTransformSource(source, context, defaultTransformSource)
-}
+export const transformSource = HAS_UPDATED_HOOKS
+  ? undefined
+  : (source, context, defaultTransformSource) => {
+      const { url, format } = context
+
+      if (extensionsRegex.test(new URL(url).pathname)) {
+        let filename = url
+        if (!isWindows) filename = fileURLToPath(url)
+
+        const { js } = esbuildTransformSync(source, filename, url, format)
+
+        return {
+          source: js,
+        }
+      }
+
+      // Let Node.js handle all other sources.
+      return defaultTransformSource(source, context, defaultTransformSource)
+    }

package.json

@@ -33,7 +33,8 @@
     "test": "node --experimental-loader ./loader.mjs test/entry.ts"
   },
   "dependencies": {
-    "esbuild": "^0.13.3"
+    "esbuild": "^0.13.3",
+    "semver": "^7.3.5"
   },
   "devDependencies": {
     "@antfu/eslint-config": "^0.9.0",