readPackage and readPackageScope

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, readPackageScope, cjsParseCache,
+  wrapSafe, Module, cjsParseCache,
   get hasLoadedAnyUserCJSModule() { return hasLoadedAnyUserCJSModule; },
   initializeCJS,
 };
@@ -89,7 +88,6 @@ const { internalCompileFunction } = require('internal/vm');
 const assert = require('internal/assert');
 const fs = require('fs');
 const path = require('path');
-const { sep } = path;
 const { internalModuleStat } = internalBinding('fs');
 const { safeGetenv } = internalBinding('credentials');
 const {
@@ -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
@@ -574,7 +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;
   }
@@ -1134,7 +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');
@@ -1431,7 +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/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

@@ -49,7 +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';