esm: refactor createDynamicModule()

This commit refactors createDynamicModule() for readability:
- The map() callback functions are named and moved to a higher
scope.
- The two export map() loops are combined.
- JSON.stringify() is only called once per import.
PR-URL: #27809
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: cjihrig

lib/internal/modules/esm/create_dynamic_module.js

@@ -4,24 +4,27 @@ const { ArrayPrototype, JSON, Object } = primordials;
 
 constdebug=require('internal/util/debuglog').debuglog('esm');
 
-constcreateDynamicModule=(imports,exports,url='',evaluate)=>{
-debug('creating ESM facade for %s with exports: %j',url,exports);
-constnames=ArrayPrototype.map(exports,(name)=>`${name}`);
-
-constsource=`
-${ArrayPrototype.join(ArrayPrototype.map(imports,(impt,index)=>
-`import * as $import_${index} from ${JSON.stringify(impt)};
-import.meta.imports[${JSON.stringify(impt)}] = $import_${index};`),'\n')
+functioncreateImport(impt,index){
+constimptPath=JSON.stringify(impt);
+return`import * as $import_${index} from ${imptPath};
+import.meta.imports[${imptPath}] = $import_${index};`;
 }
-${ArrayPrototype.join(ArrayPrototype.map(names,(name)=>
-`let $${name};
+
+functioncreateExport(expt){
+constname=`${expt}`;
+return`let $${name};
 export { $${name} as ${name} };
 import.meta.exports.${name} = {
  get: () => $${name},
  set: (v) => $${name} = v,
-};`),'\n')
+};`;
 }
 
+constcreateDynamicModule=(imports,exports,url='',evaluate)=>{
+debug('creating ESM facade for %s with exports: %j',url,exports);
+constsource=`
+${ArrayPrototype.join(ArrayPrototype.map(imports,createImport),'\n')}
+${ArrayPrototype.join(ArrayPrototype.map(exports,createExport),'\n')}
 import.meta.done();
 `;
 const{ ModuleWrap, callbackMap }=internalBinding('module_wrap');