feat: Support ESM logging module

start.js

@@ -16,6 +16,7 @@ const {
   exit,
   requireModule,
   requireESModule,
+  requireModuleDefaultExport,
   requireFastifyForModule,
   requireServerPluginFromPath,
   showHelpForCommand,
@@ -120,7 +121,7 @@ async function runFastify (args, additionalOptions, serverOptions) {
   let logger
   if (opts.loggingModule) {
     try {
-      logger = requireModule(opts.loggingModule)
+      logger = await requireModuleDefaultExport(opts.loggingModule)
     } catch (e) {
       module.exports.stop(e)
     }

templates/plugin/index.d.ts

@@ -7,7 +7,7 @@ declare module 'fastify' {
   }
 }
 
-declare const example: FastifyPluginCallback<() => string>
+declare const example: FastifyPluginCallback<{}>
 
 export { example }
 export default example

test/data/custom-logger.mjs

@@ -0,0 +1,6 @@
+export default {
+  name: 'Custom Logger',
+  customLevels: {
+    test: 99
+  }
+}

test/start.test.js

@@ -947,6 +947,17 @@ test('should support custom logger configuration', async t => {
   t.pass('server closed')
 })
 
+test('should support custom logger configuration in ESM', async t => {
+  t.plan(2)
+
+  const argv = ['-L', './test/data/custom-logger.mjs', './examples/plugin.js']
+  const fastify = await start.start(argv)
+  t.ok(fastify.log.test)
+
+  await fastify.close()
+  t.pass('server closed')
+})
+
 test('preloading a built-in module works', async t => {
   t.plan(1)
 

util.js

@@ -39,6 +39,22 @@ async function requireESModule (moduleName) {
   }
 }
 
+async function requireModuleDefaultExport (moduleName) {
+  if (fs.existsSync(moduleName)) {
+    const packageType = await getPackageType(path.dirname(moduleName))
+    const type = getScriptType(moduleName, packageType)
+
+    const moduleFilePath = path.resolve(moduleName)
+    if (type === 'module') {
+      return (await import(url.pathToFileURL(moduleFilePath))).default
+    } else {
+      return require(moduleFilePath)
+    }
+  } else {
+    return (await import(moduleName)).default
+  }
+}
+
 function requireFastifyForModule (modulePath) {
   try {
     const basedir = path.resolve(process.cwd(), modulePath)
@@ -118,6 +134,7 @@ module.exports = {
   exit,
   requireModule,
   requireESModule,
+  requireModuleDefaultExport,
   requireFastifyForModule,
   showHelpForCommand,
   requireServerPluginFromPath