Remove cjsRetryAsESMCache

Author: GeoffreyBooth

lib/internal/modules/cjs/loader.js

@@ -69,18 +69,10 @@ const cjsParseCache = new SafeWeakMap();
  */
 const cjsExportsCache = new SafeWeakMap();
 
-/**
- * Map of CJS modules where the initial attempt to parse as CommonJS failed;
- * we want to retry as ESM but avoid reading the module from disk again.
- * @type {SafeMap<string, string>} filename: contents
- */
-const cjsRetryAsESMCache = new SafeMap();
-
 // Set first due to cycle with ESM loader functions.
 module.exports = {
   cjsExportsCache,
   cjsParseCache,
-  cjsRetryAsESMCache,
   initializeCJS,
   Module,
   wrapSafe,
@@ -1304,7 +1296,7 @@ function wrapSafe(filename, content, cjsModuleInstance, codeCache) {
     if (process.mainModule === cjsModuleInstance) {
       if (getOptionValue('--experimental-detect-module')) {
         // For the main entry point, cache the source to potentially retry as ESM.
-        cjsRetryAsESMCache.set(filename, content);
+        process.mainModule._retryAsESMSource = content;
       } else {
         // We only enrich the error (print a warning) if we're sure we're going to for-sure throw it; so if we're
         // retrying as ESM, wait until we know whether we're going to retry before calling `enrichCJSError`.

lib/internal/modules/run_main.js

@@ -168,9 +168,9 @@ function executeUserEntryPoint(main = process.argv[1]) {
       try {
         Module._load(main, null, true);
       } catch (error) {
-        const { cjsRetryAsESMCache } = require('internal/modules/cjs/loader');
-        const source = cjsRetryAsESMCache.get(resolvedMain);
-        cjsRetryAsESMCache.delete(resolvedMain);
+        const source = process.mainModule._retryAsESMSource;
+        // In case the entry point is a large file, such as a bundle, release it from memory since we're done with it.
+        process.mainModule._retryAsESMSource = undefined; // No need to `delete` since we don't care if the key exists.
         const { shouldRetryAsESM } = require('internal/modules/helpers');
         retryAsESM = shouldRetryAsESM(error.message, source);
         if (!retryAsESM) {