fs: restore fs patchability in ESM loader

Temporarily restore fs patchability in ESM loader as a workaround
for helping downstream projects that depend on this undocumented
hidden contract transition into using hook proper APIs. This patch
intentionally avoids adding a test and instead adds warning
comments to hopefully steer new code away from depending on it.
PR-URL: #62835
Refs: #62012
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: joyeecheung

lib/internal/modules/esm/load.js

@@ -9,7 +9,7 @@ const {
 
 const{ defaultGetFormat }=require('internal/modules/esm/get_format');
 const{ validateAttributes, emitImportAssertionWarning }=require('internal/modules/esm/assert');
-const{ readFileSync }=require('fs');
+constfs=require('fs');
 
 const{Buffer: {from: BufferFrom}}=require('buffer');
 
@@ -34,7 +34,11 @@ function getSourceSync(url, context) {
 constresponseURL=href;
 letsource;
 if(protocol==='file:'){
-source=readFileSync(url);
+// If you are reading this code to figure out how to patch Node.js module loading
+// behavior - DO NOT depend on the patchability in new code: Node.js
+// internals may stop going through the JavaScript fs module entirely.
+// Prefer module.registerHooks() or other more formal fs hooks released in the future.
+source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
 constresult=dataURLProcessor(url);
 if(result==='failure'){

lib/internal/modules/esm/resolve.js

@@ -25,7 +25,7 @@ const {
 constassert=require('internal/assert');
 constinternalFS=require('internal/fs/utils');
 const{ BuiltinModule }=require('internal/bootstrap/realm');
-const{ realpathSync }=require('fs');
+constfs=require('fs');
 const{ getOptionValue }=require('internal/options');
 // Do not eagerly grab .manifest, it may be in TDZ
 const{ sep,posix: {relative: relativePosixPath}, resolve }=require('path');
@@ -273,7 +273,11 @@ function finalizeResolution(resolved, base, preserveSymlinks) {
 }
 
 if(!preserveSymlinks){
-constreal=realpathSync(path,{
+// If you are reading this code to figure out how to patch Node.js module loading
+// behavior - DO NOT depend on the patchability in new code: Node.js
+// internals may stop going through the JavaScript fs module entirely.
+// Prefer module.registerHooks() or other more formal fs hooks released in the future.
+constreal=fs.realpathSync(path,{
 [internalFS.realpathCacheKey]: realpathCache,
 });
 const{ search, hash }=resolved;

lib/internal/modules/esm/translators.js

@@ -23,7 +23,7 @@ const {
 
 const{ BuiltinModule }=require('internal/bootstrap/realm');
 constassert=require('internal/assert');
-const{ readFileSync }=require('fs');
+constfs=require('fs');
 const{ dirname, extname }=require('path');
 const{
  assertBufferSource,
@@ -342,7 +342,11 @@ translators.set('commonjs', function commonjsStrategy(url, translateContext, par
 
 try{
 // We still need to read the FS to detect the exports.
-translateContext.source??=readFileSync(newURL(url),'utf8');
+// If you are reading this code to figure out how to patch Node.js module loading
+// behavior - DO NOT depend on the patchability in new code: Node.js
+// internals may stop going through the JavaScript fs module entirely.
+// Prefer module.registerHooks() or other more formal fs hooks released in the future.
+translateContext.source??=fs.readFileSync(newURL(url),'utf8');
 }catch{
 // Continue regardless of error.
 }