From 5f2bb885f8027e2789a1fa8679d242162b4a8633 Mon Sep 17 00:00:00 2001
From: Antoine du Hamel <duhamelantoine1995@gmail.com>
Date: Tue, 29 Dec 2020 20:07:57 +0100
Subject: [PATCH] module: refactor to avoid unsafe array iteration

PR-URL: https://github.com/nodejs/node/pull/36680
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
---
 lib/internal/modules/esm/get_format.js      |  4 ++--
 lib/internal/modules/esm/get_source.js      |  2 +-
 lib/internal/modules/esm/module_job.js      |  5 +++--
 lib/internal/modules/esm/module_map.js      |  1 +
 lib/internal/modules/esm/translators.js     | 10 ++++++----
 lib/internal/modules/package_json_reader.js |  2 +-
 6 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/lib/internal/modules/esm/get_format.js b/lib/internal/modules/esm/get_format.js
index 51b207ea75d131..b48741c422c47f 100644
--- a/lib/internal/modules/esm/get_format.js
+++ b/lib/internal/modules/esm/get_format.js
@@ -42,10 +42,10 @@ function defaultGetFormat(url, context, defaultGetFormatUnused) {
   }
   const parsed = new URL(url);
   if (parsed.protocol === 'data:') {
-    const [ , mime ] = RegExpPrototypeExec(
+    const { 1: mime } = RegExpPrototypeExec(
       /^([^/]+\/[^;,]+)(?:[^,]*?)(;base64)?,/,
       parsed.pathname,
-    ) || [ null, null, null ];
+    ) || [ , null ];
     const format = ({
       '__proto__': null,
       'text/javascript': 'module',
diff --git a/lib/internal/modules/esm/get_source.js b/lib/internal/modules/esm/get_source.js
index b2cf0c3bd28aa2..155a019802f0ba 100644
--- a/lib/internal/modules/esm/get_source.js
+++ b/lib/internal/modules/esm/get_source.js
@@ -31,7 +31,7 @@ async function defaultGetSource(url, { format } = {}, defaultGetSource) {
     if (!match) {
       throw new ERR_INVALID_URL(url);
     }
-    const [ , base64, body ] = match;
+    const { 1: base64, 2: body } = match;
     source = Buffer.from(body, base64 ? 'base64' : 'utf8');
   } else {
     throw new ERR_INVALID_URL_SCHEME(['file', 'data']);
diff --git a/lib/internal/modules/esm/module_job.js b/lib/internal/modules/esm/module_job.js
index 5043da896622be..6cf968553bae6d 100644
--- a/lib/internal/modules/esm/module_job.js
+++ b/lib/internal/modules/esm/module_job.js
@@ -110,8 +110,9 @@ class ModuleJob {
                                   ' does not provide an export named')) {
         const splitStack = StringPrototypeSplit(e.stack, '\n');
         const parentFileUrl = splitStack[0];
-        const [, childSpecifier, name] = StringPrototypeMatch(e.message,
-                                                              /module '(.*)' does not provide an export named '(.+)'/);
+        const { 1: childSpecifier, 2: name } = StringPrototypeMatch(
+          e.message,
+          /module '(.*)' does not provide an export named '(.+)'/);
         const childFileURL =
             await this.loader.resolve(childSpecifier, parentFileUrl);
         const format = await this.loader.getFormat(childFileURL);
diff --git a/lib/internal/modules/esm/module_map.js b/lib/internal/modules/esm/module_map.js
index 9c51c7c48779f3..9e1116a5647f5f 100644
--- a/lib/internal/modules/esm/module_map.js
+++ b/lib/internal/modules/esm/module_map.js
@@ -12,6 +12,7 @@ const { validateString } = require('internal/validators');
 
 // Tracks the state of the loader-level module cache
 class ModuleMap extends SafeMap {
+  constructor(i) { super(i); } // eslint-disable-line no-useless-constructor
   get(url) {
     validateString(url, 'url');
     return super.get(url);
diff --git a/lib/internal/modules/esm/translators.js b/lib/internal/modules/esm/translators.js
index 66636d9ce092b5..b685989345b962 100644
--- a/lib/internal/modules/esm/translators.js
+++ b/lib/internal/modules/esm/translators.js
@@ -3,6 +3,7 @@
 /* global WebAssembly */
 
 const {
+  ArrayPrototypeForEach,
   ArrayPrototypeMap,
   Boolean,
   JSONParse,
@@ -12,6 +13,7 @@ const {
   PromisePrototypeCatch,
   PromiseReject,
   RegExpPrototypeTest,
+  SafeArrayIterator,
   SafeMap,
   SafeSet,
   StringPrototypeReplace,
@@ -246,7 +248,7 @@ function cjsPreparseModuleExports(filename) {
     reexports = [];
   }
 
-  const exportNames = new SafeSet(exports);
+  const exportNames = new SafeSet(new SafeArrayIterator(exports));
 
   // Set first for cycles.
   cjsParseCache.set(module, { source, exportNames, loaded });
@@ -255,12 +257,12 @@ function cjsPreparseModuleExports(filename) {
     module.filename = filename;
     module.paths = CJSModule._nodeModulePaths(module.path);
   }
-  for (const reexport of reexports) {
+  ArrayPrototypeForEach(reexports, (reexport) => {
     let resolved;
     try {
       resolved = CJSModule._resolveFilename(reexport, module);
     } catch {
-      continue;
+      return;
     }
     const ext = extname(resolved);
     if ((ext === '.js' || ext === '.cjs' || !CJSModule._extensions[ext]) &&
@@ -269,7 +271,7 @@ function cjsPreparseModuleExports(filename) {
       for (const name of reexportNames)
         exportNames.add(name);
     }
-  }
+  });
 
   return { module, exportNames };
 }
diff --git a/lib/internal/modules/package_json_reader.js b/lib/internal/modules/package_json_reader.js
index 4a2b0e6ddb3ed8..09eb12bd1533bf 100644
--- a/lib/internal/modules/package_json_reader.js
+++ b/lib/internal/modules/package_json_reader.js
@@ -18,7 +18,7 @@ function read(jsonPath) {
     return cache.get(jsonPath);
   }
 
-  const [string, containsKeys] = internalModuleReadJSON(
+  const { 0: string, 1: containsKeys } = internalModuleReadJSON(
     toNamespacedPath(jsonPath)
   );
   const result = { string, containsKeys };