esm: share package.json string cache between ESM and CJS loaders

Refs: nodejs#30674

Author: shackijj

lib/internal/modules/cjs/loader.js

@@ -59,10 +59,8 @@ const fs = require('fs');
 const internalFS = require('internal/fs/utils');
 const path = require('path');
 const { emitWarningSync } = require('internal/process/warning');
-const {
-  internalModuleReadJSON,
-  internalModuleStat
-} = internalBinding('fs');
+const { internalModuleStat } = internalBinding('fs');
+const packageJsonReader = require('internal/modules/package_json_reader');
 const { safeGetenv } = internalBinding('credentials');
 const {
   makeRequireFunction,
@@ -94,10 +92,8 @@ const {
 const { validateString } = require('internal/validators');
 const pendingDeprecation = getOptionValue('--pending-deprecation');
 
-const packageJsonCache = new SafeMap();
-
 module.exports = {
-  wrapSafe, Module, toRealPath, readPackageScope, readPackage, packageJsonCache,
+  wrapSafe, Module, toRealPath, readPackageScope,
   get hasLoadedAnyUserCJSModule() { return hasLoadedAnyUserCJSModule; }
 };
 
@@ -241,22 +237,17 @@ Module._debug = deprecate(debug, 'Module._debug is deprecated.', 'DEP0077');
 //   -> a
 //   -> a.<ext>
 //   -> a/index.<ext>
-/**
- *
- * @param {string} jsonPath
- * @returns {string|undefined}
- */
-function readJsonDefaultStrategy(jsonPath) {
-  return internalModuleReadJSON(path.toNamespacedPath(jsonPath));
-}
 
-function readPackage(requestPath, readJsonStrategy = readJsonDefaultStrategy) {
+const packageJsonCache = new SafeMap();
+
+function readPackage(requestPath) {
   const jsonPath = path.resolve(requestPath, 'package.json');
 
   const existing = packageJsonCache.get(jsonPath);
   if (existing !== undefined) return existing;
 
-  const json = readJsonStrategy(jsonPath);
+  const result = packageJsonReader.read(path.toNamespacedPath(jsonPath));
+  const json = result.containsKeys === false ? '{}' : result.string;
   if (json === undefined) {
     packageJsonCache.set(jsonPath, false);
     return false;
@@ -284,8 +275,7 @@ function readPackage(requestPath, readJsonStrategy = readJsonDefaultStrategy) {
   }
 }
 
-function readPackageScope(
-  checkPath, readJsonStrategy = readJsonDefaultStrategy) {
+function readPackageScope(checkPath) {
   const rootSeparatorIndex = checkPath.indexOf(path.sep);
   let separatorIndex;
   while (
@@ -294,7 +284,7 @@ function readPackageScope(
     checkPath = checkPath.slice(0, separatorIndex);
     if (checkPath.endsWith(path.sep + 'node_modules'))
       return false;
-    const pjson = readPackage(checkPath, readJsonStrategy);
+    const pjson = readPackage(checkPath);
     if (pjson) return {
       path: checkPath,
       data: pjson

lib/internal/modules/esm/resolve.js

@@ -4,6 +4,7 @@ const {
   ArrayIsArray,
   ArrayPrototypeJoin,
   ArrayPrototypeShift,
+  JSONParse,
   JSONStringify,
   ObjectFreeze,
   ObjectGetOwnPropertyNames,
@@ -23,23 +24,14 @@ const {
 const assert = require('internal/assert');
 const internalFS = require('internal/fs/utils');
 const { NativeModule } = require('internal/bootstrap/loaders');
-const {
-  Module: CJSModule,
-  readPackageScope,
-  readPackage,
-  packageJsonCache
-} = require('internal/modules/cjs/loader');
 const {
   realpathSync,
   statSync,
   Stats,
-  openSync,
-  fstatSync,
-  readFileSync,
-  closeSync
 } = require('fs');
 const { getOptionValue } = require('internal/options');
-const { sep, relative, join } = require('path');
+const { sep, relative } = require('path');
+const { Module: CJSModule } = require('internal/modules/cjs/loader');
 const preserveSymlinks = getOptionValue('--preserve-symlinks');
 const preserveSymlinksMain = getOptionValue('--preserve-symlinks-main');
 const typeFlag = getOptionValue('--input-type');
@@ -55,6 +47,7 @@ const {
   ERR_UNSUPPORTED_ESM_URL_SCHEME,
 } = require('internal/errors').codes;
 
+const packageJsonReader = require('internal/modules/package_json_reader');
 const DEFAULT_CONDITIONS = ObjectFreeze(['node', 'import']);
 const DEFAULT_CONDITIONS_SET = new SafeSet(DEFAULT_CONDITIONS);
 
@@ -70,6 +63,7 @@ function getConditionsSet(conditions) {
 }
 
 const realpathCache = new SafeMap();
+const packageJSONCache = new SafeMap();  /* string -> PackageConfig */
 
 function tryStatSync(path) {
   try {
@@ -79,6 +73,77 @@ function tryStatSync(path) {
   }
 }
 
+function getPackageConfig(path) {
+  const existing = packageJSONCache.get(path);
+  if (existing !== undefined) {
+    return existing;
+  }
+  const source = packageJsonReader.read(path).string;
+  if (source === undefined) {
+    const packageConfig = {
+      exists: false,
+      main: undefined,
+      name: undefined,
+      type: 'none',
+      exports: undefined
+    };
+    packageJSONCache.set(path, packageConfig);
+    return packageConfig;
+  }
+
+  let packageJSON;
+  try {
+    packageJSON = JSONParse(source);
+  } catch (error) {
+    const errorPath = StringPrototypeSlice(path, 0, path.length - 13);
+    throw new ERR_INVALID_PACKAGE_CONFIG(errorPath, error.message, true);
+  }
+
+  let { main, name, type } = packageJSON;
+  const { exports } = packageJSON;
+  if (typeof main !== 'string') main = undefined;
+  if (typeof name !== 'string') name = undefined;
+  // Ignore unknown types for forwards compatibility
+  if (type !== 'module' && type !== 'commonjs') type = 'none';
+
+  const packageConfig = {
+    exists: true,
+    main,
+    name,
+    type,
+    exports
+  };
+  packageJSONCache.set(path, packageConfig);
+  return packageConfig;
+}
+
+function getPackageScopeConfig(resolved, base) {
+  let packageJSONUrl = new URL('./package.json', resolved);
+  while (true) {
+    const packageJSONPath = packageJSONUrl.pathname;
+    if (StringPrototypeEndsWith(packageJSONPath, 'node_modules/package.json'))
+      break;
+    const packageConfig = getPackageConfig(fileURLToPath(packageJSONUrl), base);
+    if (packageConfig.exists) return packageConfig;
+
+    const lastPackageJSONUrl = packageJSONUrl;
+    packageJSONUrl = new URL('../package.json', packageJSONUrl);
+
+    // Terminates at root where ../package.json equals ../../package.json
+    // (can't just check "/package.json" for Windows support).
+    if (packageJSONUrl.pathname === lastPackageJSONUrl.pathname) break;
+  }
+  const packageConfig = {
+    exists: false,
+    main: undefined,
+    name: undefined,
+    type: 'none',
+    exports: undefined
+  };
+  packageJSONCache.set(fileURLToPath(packageJSONUrl), packageConfig);
+  return packageConfig;
+}
+
 /*
  * Legacy CommonJS main resolution:
  * 1. let M = pkg_url + (json main field)
@@ -331,7 +396,7 @@ function isConditionalExportsMainSugar(exports, packageJSONUrl, base) {
 
 
 function packageMainResolve(packageJSONUrl, packageConfig, base, conditions) {
-  if (packageConfig) {
+  if (packageConfig.exists) {
     const exports = packageConfig.exports;
     if (exports !== undefined) {
       if (isConditionalExportsMainSugar(exports, packageJSONUrl, base)) {
@@ -408,51 +473,9 @@ function packageExportsResolve(
   throwExportsNotFound(packageSubpath, packageJSONUrl, base);
 }
 
-function readIfFile(path) {
-  let fd;
-  try {
-    fd = openSync(path, 'r');
-  } catch {
-    return undefined;
-  }
-  try {
-    if (!fstatSync(fd).isFile()) return undefined;
-    return readFileSync(fd, 'utf8');
-  } finally {
-    closeSync(fd);
-  }
-}
-
-function catchInvalidPackage(error, path) {
-  if (error instanceof SyntaxError) {
-    const packageJsonPath = join(path, 'package.json');
-    const message = StringPrototypeSlice(
-      error.message, ('Error parsing ' + packageJsonPath + ': ').length);
-    throw new ERR_INVALID_PACKAGE_CONFIG(path, message, true);
-  }
-  throw error;
-}
-
-function readPackageESM(path) {
-  try {
-    return readPackage(path, readIfFile);
-  } catch (error) {
-    catchInvalidPackage(error, path);
-  }
-}
-
-function readPackageScopeESM(url) {
-  const path = fileURLToPath(url);
-  try {
-    return readPackageScope(path, readIfFile);
-  } catch (error) {
-    catchInvalidPackage(error, path);
-  }
-}
-
 function getPackageType(url) {
-  const packageConfig = readPackageScopeESM(url);
-  return packageConfig ? packageConfig.data.type : 'none';
+  const packageConfig = getPackageScopeConfig(url, url);
+  return packageConfig.type;
 }
 
 /**
@@ -496,13 +519,12 @@ function packageResolve(specifier, base, conditions) {
     '' : '.' + StringPrototypeSlice(specifier, separatorIndex);
 
   // ResolveSelf
-  const packageScope = readPackageScopeESM(base);
-  if (packageScope !== false) {
-    const packageConfig = packageScope.data;
+  const packageConfig = getPackageScopeConfig(base, base);
+  if (packageConfig.exists) {
     // TODO(jkrems): Find a way to forward the pair/iterator already generated
     // while executing GetPackageScopeConfig
     let packageJSONUrl;
-    for (const [ filename, packageConfigCandidate ] of packageJsonCache) {
+    for (const [ filename, packageConfigCandidate ] of packageJSONCache) {
       if (packageConfig === packageConfigCandidate) {
         packageJSONUrl = pathToFileURL(filename);
         break;
@@ -540,15 +562,13 @@ function packageResolve(specifier, base, conditions) {
     }
 
     // Package match.
-    const packagePath = StringPrototypeSlice(
-      packageJSONPath, 0, packageJSONPath.length - 13);
-    const packageConfig = readPackageESM(packagePath);
+    const packageConfig = getPackageConfig(packageJSONPath, base);
     if (packageSubpath === './') {
       return new URL('./', packageJSONUrl);
     } else if (packageSubpath === '') {
       return packageMainResolve(packageJSONUrl, packageConfig, base,
                                 conditions);
-    } else if (packageConfig && packageConfig.exports !== undefined) {
+    } else if (packageConfig.exports !== undefined) {
       return packageExportsResolve(
         packageJSONUrl, packageSubpath, packageConfig, base, conditions);
     } else {

lib/internal/modules/package_json_reader.js

@@ -0,0 +1,22 @@
+'use strict';
+
+const { SafeMap } = primordials;
+const { internalModuleReadJSON } = internalBinding('fs');
+
+const cache = new SafeMap();
+
+/**
+ *
+ * @param {string} path
+ */
+function read(path) {
+  if (cache.has(path)) {
+    return cache.get(path);
+  }
+
+  const result = internalModuleReadJSON(path);
+  cache.set(path, result);
+  return result;
+}
+
+module.exports = { read };

node.gyp

@@ -158,6 +158,7 @@
       'lib/internal/main/run_third_party_main.js',
       'lib/internal/main/worker_thread.js',
       'lib/internal/modules/run_main.js',
+      'lib/internal/modules/package_json_reader.js',
       'lib/internal/modules/cjs/helpers.js',
       'lib/internal/modules/cjs/loader.js',
       'lib/internal/modules/esm/loader.js',