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,
  get hasLoadedAnyUserCJSModule() { return hasLoadedAnyUserCJSModule; },
  initializeCJS,
 };
@@ -88,9 +87,7 @@ const {
 const { internalCompileFunction } = require('internal/vm');
 const assert = require('internal/assert');
 const fs = require('fs');
-const internalFS = require('internal/fs/utils');
 const path = 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');
 const packageJsonReader = 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}
- */
-function readPackage(requestPath) {
- return packageJsonReader.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.
- */
-function readPackageScope(checkPath) {
- const rootSeparatorIndex = StringPrototypeIndexOf(checkPath, sep);
- let separatorIndex;
- const enabledPermission = 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)) {
- return false;
- }
- if (StringPrototypeEndsWith(checkPath, sep + 'node_modules')) {
- return false;
- }
- const pjson = _readPackage(checkPath + sep);
- if (pjson.exists) {
- return {
- data: pjson,
- path: checkPath,
- };
- }
- } while (separatorIndex > rootSeparatorIndex);
- return false;
-}
-
 /**
  * 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) {
  return actual;
 }
 
-/**
- * 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>}
- */
-const realpathCache = new SafeMap();
-
 /**
  * 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) {
  return toRealPath(requestPath);
 }
 
-
-/**
- * Resolves the path of a given `require` specifier, following symlinks.
- * @param {string} requestPath The `require` specifier
- */
-function toRealPath(requestPath) {
- return fs.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) {
 function trySelf(parentPath, request) {
  if (!parentPath) { return false; }
 
- const { data: pkg, path: pkgPath } = readPackageScope(parentPath);
+ const { data: pkg, path: pkgPath } = packageJsonReader.readPackageScope(parentPath);
  if (!pkg || pkg.exports == null || pkg.name === undefined) {
  return false;
  }
@@ -1153,7 +1093,7 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 
  if (request[0] === '#' && (parent?.filename || parent?.id === '<repl>')) {
  const parentPath = parent?.filename ?? process.cwd() + path.sep;
- const pkg = readPackageScope(parentPath) || { __proto__: null };
+ const pkg = 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')) {
- const pkg = readPackageScope(filename) || { __proto__: null };
+ const pkg = packageJsonReader.readPackageScope(filename) || { __proto__: null };
  // Function require shouldn't be used in ES modules.
  if (pkg.data?.type === 'module') {
  const parent = moduleParentCache.get(module);

lib/internal/modules/helpers.js

@@ -21,6 +21,8 @@ const {
 const { BuiltinModule } = require('internal/bootstrap/realm');
 
 const { validateString } = require('internal/validators');
+const fs = require('fs'); // Import all of `fs` so that it can be monkey-patched.
+const internalFS = require('internal/fs/utils');
 const path = 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>}
+ */
+const realpathCache = new SafeMap();
+/**
+ * Resolves the path of a given `require` specifier, following symlinks.
+ * @param {string} requestPath The `require` specifier
+ */
+function toRealPath(requestPath) {
+ return fs.realpathSync(requestPath, {
+ [internalFS.realpathCacheKey]: realpathCache,
+ });
+}
+
 /** @type {Set<string>} */
 let cjsConditions;
 /**
@@ -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');
+const permission = require('internal/process/permission');
 const { kEmptyObject, setOwnProperty } = require('internal/util');
 
 const { fileURLToPath, pathToFileURL } = require('internal/url');
@@ -111,4 +116,47 @@ function read(jsonPath, { base, specifier, isESM } = kEmptyObject) {
  return result;
 }
 
-module.exports = { read };
+/**
+ * @param {string} requestPath
+ * @return {PackageConfig}
+ */
+function readPackage(requestPath) {
+ return read(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.
+ */
+function readPackageScope(checkPath) {
+ const rootSeparatorIndex = StringPrototypeIndexOf(checkPath, sep);
+ let separatorIndex;
+ const enabledPermission = 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)) {
+ return false;
+ }
+ if (StringPrototypeEndsWith(checkPath, sep + 'node_modules')) {
+ return false;
+ }
+ const pjson = readPackage(checkPath + sep);
+ if (pjson.exists) {
+ return {
+ data: pjson,
+ path: checkPath,
+ };
+ }
+ } while (separatorIndex > rootSeparatorIndex);
+ return false;
+}
+
+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');
  let mainPath = Module._findPath(path.resolve(main), null, true);
  if (!mainPath) { return; }
 
  const preserveSymlinksMain = 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')) { return true; }
  if (!mainPath || StringPrototypeEndsWith(mainPath, '.cjs')) { return false; }
 
- const { readPackageScope } = require('internal/modules/cjs/loader');
+ const { readPackageScope } = require('internal/modules/package_json_reader');
  const pkg = readPackageScope(mainPath);
  // No need to guard `pkg` as it can only be an object or `false`.
  return pkg.data?.type === 'module' || getOptionValue('--experimental-default-type') === 'module';