module: move helpers out of cjs loader

PR-URL: #49912
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>

Author: GeoffreyBooth

lib/internal/modules/cjs/loader.js

@@ -55,7 +55,6 @@ const {
  StringPrototypeCharAt,
  StringPrototypeCharCodeAt,
  StringPrototypeEndsWith,
- StringPrototypeLastIndexOf,
  StringPrototypeIndexOf,
  StringPrototypeRepeat,
  StringPrototypeSlice,
@@ -68,7 +67,7 @@ const cjsParseCache = new SafeWeakMap();
 
 // Set first due to cycle with ESM loader functions.
 module.exports={
- wrapSafe, Module,toRealPath, readPackageScope,cjsParseCache,
+ wrapSafe, Module, cjsParseCache,
 gethasLoadedAnyUserCJSModule(){returnhasLoadedAnyUserCJSModule;},
  initializeCJS,
 };
@@ -88,9 +87,7 @@ const {
 const{ internalCompileFunction }=require('internal/vm');
 constassert=require('internal/assert');
 constfs=require('fs');
-constinternalFS=require('internal/fs/utils');
 constpath=require('path');
-const{ sep }=path;
 const{ internalModuleStat }=internalBinding('fs');
 const{ safeGetenv }=internalBinding('credentials');
 const{
@@ -106,6 +103,7 @@ const {
  makeRequireFunction,
  normalizeReferrerURL,
  stripBOM,
+ toRealPath,
 }=require('internal/modules/helpers');
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
@@ -403,15 +401,7 @@ function initializeCJS() {
 // -> a.<ext>
 // -> a/index.<ext>
 
-/**
- * @param {string} requestPath
- * @return {PackageConfig}
- */
-functionreadPackage(requestPath){
-returnpackageJsonReader.read(path.resolve(requestPath,'package.json'));
-}
-
-let_readPackage=readPackage;
+let_readPackage=packageJsonReader.readPackage;
 ObjectDefineProperty(Module,'_readPackage',{
 __proto__: null,
 get(){return_readPackage;},
@@ -423,37 +413,6 @@ ObjectDefineProperty(Module, '_readPackage', {
 configurable: true,
 });
 
-/**
- * Get the nearest parent package.json file from a given path.
- * Return the package.json data and the path to the package.json file, or false.
- * @param {string} checkPath The path to start searching from.
- */
-functionreadPackageScope(checkPath){
-constrootSeparatorIndex=StringPrototypeIndexOf(checkPath,sep);
-letseparatorIndex;
-constenabledPermission=permission.isEnabled();
-do{
-separatorIndex=StringPrototypeLastIndexOf(checkPath,sep);
-checkPath=StringPrototypeSlice(checkPath,0,separatorIndex);
-// Stop the search when the process doesn't have permissions
-// to walk upwards
-if(enabledPermission&&!permission.has('fs.read',checkPath+sep)){
-returnfalse;
-}
-if(StringPrototypeEndsWith(checkPath,sep+'node_modules')){
-returnfalse;
-}
-constpjson=_readPackage(checkPath+sep);
-if(pjson.exists){
-return{
-data: pjson,
-path: checkPath,
-};
-}
-}while(separatorIndex>rootSeparatorIndex);
-returnfalse;
-}
-
 /**
  * Try to load a specifier as a package.
  * @param {string} requestPath The path to what we are trying to load
@@ -498,14 +457,6 @@ function tryPackage(requestPath, exts, isMain, originalPath) {
 returnactual;
 }
 
-/**
- * Cache for storing resolved real paths of modules.
- * In order to minimize unnecessary lstat() calls, this cache is a list of known-real paths.
- * Set to an empty Map to reset.
- * @type {Map<string, string>}
- */
-constrealpathCache=newSafeMap();
-
 /**
  * Check if the file exists and is not a directory if using `--preserve-symlinks` and `isMain` is false, keep symlinks
  * intact, otherwise resolve to the absolute realpath.
@@ -521,17 +472,6 @@ function tryFile(requestPath, isMain) {
 returntoRealPath(requestPath);
 }
 
-
-/**
- * Resolves the path of a given `require` specifier, following symlinks.
- * @param {string} requestPath The `require` specifier
- */
-functiontoRealPath(requestPath){
-returnfs.realpathSync(requestPath,{
-[internalFS.realpathCacheKey]: realpathCache,
-});
-}
-
 /**
  * Given a path, check if the file exists with any of the set extensions.
  * @param {string} basePath The path and filename without extension
@@ -593,7 +533,7 @@ function trySelfParentPath(parent) {
 functiontrySelf(parentPath,request){
 if(!parentPath){returnfalse;}
 
-const{data: pkg,path: pkgPath}=readPackageScope(parentPath);
+const{data: pkg,path: pkgPath}=packageJsonReader.readPackageScope(parentPath);
 if(!pkg||pkg.exports==null||pkg.name===undefined){
 returnfalse;
 }
@@ -1153,7 +1093,7 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 
 if(request[0]==='#'&&(parent?.filename||parent?.id==='<repl>')){
 constparentPath=parent?.filename??process.cwd()+path.sep;
-constpkg=readPackageScope(parentPath)||{__proto__: null};
+constpkg=packageJsonReader.readPackageScope(parentPath)||{__proto__: null};
 if(pkg.data?.imports!=null){
 try{
 const{ packageImportsResolve }=require('internal/modules/esm/resolve');
@@ -1450,7 +1390,7 @@ Module._extensions['.js'] = function(module, filename) {
 content=fs.readFileSync(filename,'utf8');
 }
 if(StringPrototypeEndsWith(filename,'.js')){
-constpkg=readPackageScope(filename)||{__proto__: null};
+constpkg=packageJsonReader.readPackageScope(filename)||{__proto__: null};
 // Function require shouldn't be used in ES modules.
 if(pkg.data?.type==='module'){
 constparent=moduleParentCache.get(module);

lib/internal/modules/helpers.js

@@ -21,6 +21,8 @@ const {
 const{ BuiltinModule }=require('internal/bootstrap/realm');
 
 const{ validateString }=require('internal/validators');
+constfs=require('fs');// Import all of `fs` so that it can be monkey-patched.
+constinternalFS=require('internal/fs/utils');
 constpath=require('path');
 const{ pathToFileURL, fileURLToPath,URL}=require('internal/url');
 
@@ -39,6 +41,23 @@ let debug = require('internal/util/debuglog').debuglog('module', (fn) => {
 
 /** @typedef {import('internal/modules/cjs/loader.js').Module} Module */
 
+/**
+ * Cache for storing resolved real paths of modules.
+ * In order to minimize unnecessary lstat() calls, this cache is a list of known-real paths.
+ * Set to an empty Map to reset.
+ * @type {Map<string, string>}
+ */
+constrealpathCache=newSafeMap();
+/**
+ * Resolves the path of a given `require` specifier, following symlinks.
+ * @param {string} requestPath The `require` specifier
+ */
+functiontoRealPath(requestPath){
+returnfs.realpathSync(requestPath,{
+[internalFS.realpathCacheKey]: realpathCache,
+});
+}
+
 /** @type {Set<string>} */
 letcjsConditions;
 /**
@@ -310,4 +329,5 @@ module.exports = {
  makeRequireFunction,
  normalizeReferrerURL,
  stripBOM,
+ toRealPath,
 };

lib/internal/modules/package_json_reader.js

@@ -4,12 +4,17 @@ const {
  JSONParse,
  ObjectPrototypeHasOwnProperty,
  SafeMap,
+ StringPrototypeEndsWith,
+ StringPrototypeIndexOf,
+ StringPrototypeLastIndexOf,
+ StringPrototypeSlice,
 }=primordials;
 const{
 ERR_INVALID_PACKAGE_CONFIG,
 }=require('internal/errors').codes;
 const{ internalModuleReadJSON }=internalBinding('fs');
-const{ toNamespacedPath }=require('path');
+const{ resolve, sep, toNamespacedPath }=require('path');
+constpermission=require('internal/process/permission');
 const{ kEmptyObject }=require('internal/util');
 
 const{ fileURLToPath, pathToFileURL }=require('internal/url');
@@ -128,4 +133,47 @@ function read(jsonPath, { base, specifier, isESM } = kEmptyObject) {
 returnresult;
 }
 
-module.exports={ read };
+/**
+ * @param {string} requestPath
+ * @return {PackageConfig}
+ */
+functionreadPackage(requestPath){
+returnread(resolve(requestPath,'package.json'));
+}
+
+/**
+ * Get the nearest parent package.json file from a given path.
+ * Return the package.json data and the path to the package.json file, or false.
+ * @param {string} checkPath The path to start searching from.
+ */
+functionreadPackageScope(checkPath){
+constrootSeparatorIndex=StringPrototypeIndexOf(checkPath,sep);
+letseparatorIndex;
+constenabledPermission=permission.isEnabled();
+do{
+separatorIndex=StringPrototypeLastIndexOf(checkPath,sep);
+checkPath=StringPrototypeSlice(checkPath,0,separatorIndex);
+// Stop the search when the process doesn't have permissions
+// to walk upwards
+if(enabledPermission&&!permission.has('fs.read',checkPath+sep)){
+returnfalse;
+}
+if(StringPrototypeEndsWith(checkPath,sep+'node_modules')){
+returnfalse;
+}
+constpjson=readPackage(checkPath+sep);
+if(pjson.exists){
+return{
+data: pjson,
+path: checkPath,
+};
+}
+}while(separatorIndex>rootSeparatorIndex);
+returnfalse;
+}
+
+module.exports={
+ read,
+ readPackage,
+ readPackageScope,
+};

lib/internal/modules/run_main.js

@@ -15,12 +15,13 @@ function resolveMainPath(main) {
 // Note extension resolution for the main entry point can be deprecated in a
 // future major.
 // Module._findPath is monkey-patchable here.
-const{ Module, toRealPath}=require('internal/modules/cjs/loader');
+const{ Module }=require('internal/modules/cjs/loader');
 letmainPath=Module._findPath(path.resolve(main),null,true);
 if(!mainPath){return;}
 
 constpreserveSymlinksMain=getOptionValue('--preserve-symlinks-main');
 if(!preserveSymlinksMain){
+const{ toRealPath }=require('internal/modules/helpers');
 mainPath=toRealPath(mainPath);
 }
 
@@ -48,7 +49,7 @@ function shouldUseESMLoader(mainPath) {
 if(mainPath&&StringPrototypeEndsWith(mainPath,'.mjs')){returntrue;}
 if(!mainPath||StringPrototypeEndsWith(mainPath,'.cjs')){returnfalse;}
 
-const{ readPackageScope }=require('internal/modules/cjs/loader');
+const{ readPackageScope }=require('internal/modules/package_json_reader');
 constpkg=readPackageScope(mainPath);
 // No need to guard `pkg` as it can only be an object or `false`.
 returnpkg.data?.type==='module'||getOptionValue('--experimental-default-type')==='module';