lib: replace var with let/const

PR-URL: #30440
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

lib/internal/modules/cjs/loader.js

@@ -153,7 +153,7 @@ Module.builtinModules = builtinModules;
 Module._cache = Object.create(null);
 Module._pathCache = Object.create(null);
 Module._extensions = Object.create(null);
-var modulePaths = [];
+let modulePaths = [];
 Module.globalPaths = [];
 
 let patched = false;
@@ -341,7 +341,7 @@ function toRealPath(requestPath) {
 
 // Given a path, check if the file exists with any of the set extensions
 function tryExtensions(p, exts, isMain) {
-  for (var i = 0; i < exts.length; i++) {
+  for (let i = 0; i < exts.length; i++) {
     const filename = tryFile(p + exts[i], isMain);
 
     if (filename) {
@@ -474,22 +474,22 @@ Module._findPath = function(request, paths, isMain) {
   if (entry)
     return entry;
 
-  var exts;
-  var trailingSlash = request.length > 0 &&
+  let exts;
+  let trailingSlash = request.length > 0 &&
     request.charCodeAt(request.length - 1) === CHAR_FORWARD_SLASH;
   if (!trailingSlash) {
     trailingSlash = /(?:^|\/)\.?\.$/.test(request);
   }
 
   // For each path
-  for (var i = 0; i < paths.length; i++) {
+  for (let i = 0; i < paths.length; i++) {
     // Don't search further if path doesn't exist
     const curPath = paths[i];
     if (curPath && stat(curPath) < 1) continue;
-    var basePath = resolveExports(curPath, request, absoluteRequest);
-    var filename;
+    const basePath = resolveExports(curPath, request, absoluteRequest);
+    let filename;
 
-    var rc = stat(basePath);
+    const rc = stat(basePath);
     if (!trailingSlash) {
       if (rc === 0) {  // File.
         if (!isMain) {
@@ -556,9 +556,7 @@ if (isWindows) {
       return [from + 'node_modules'];
 
     const paths = [];
-    var p = 0;
-    var last = from.length;
-    for (var i = from.length - 1; i >= 0; --i) {
+    for (let i = from.length - 1, p = 0, last = from.length; i >= 0; --i) {
       const code = from.charCodeAt(i);
       // The path segment separator check ('\' and '/') was used to get
       // node_modules path for every path segment.
@@ -597,9 +595,7 @@ if (isWindows) {
     // to be absolute.  Doing a fully-edge-case-correct path.split
     // that works on both Windows and Posix is non-trivial.
     const paths = [];
-    var p = 0;
-    var last = from.length;
-    for (var i = from.length - 1; i >= 0; --i) {
+    for (let i = from.length - 1, p = 0, last = from.length; i >= 0; --i) {
       const code = from.charCodeAt(i);
       if (code === CHAR_FORWARD_SLASH) {
         if (p !== nmLen)
@@ -744,7 +740,7 @@ Module._resolveFilename = function(request, parent, isMain, options) {
     return request;
   }
 
-  var paths;
+  let paths;
 
   if (typeof options === 'object' && options !== null) {
     if (Array.isArray(options.paths)) {
@@ -760,12 +756,12 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 
         paths = [];
 
-        for (var i = 0; i < options.paths.length; i++) {
+        for (let i = 0; i < options.paths.length; i++) {
           const path = options.paths[i];
           fakeParent.paths = Module._nodeModulePaths(path);
           const lookupPaths = Module._resolveLookupPaths(request, fakeParent);
 
-          for (var j = 0; j < lookupPaths.length; j++) {
+          for (let j = 0; j < lookupPaths.length; j++) {
             if (!paths.includes(lookupPaths[j]))
               paths.push(lookupPaths[j]);
           }
@@ -784,7 +780,7 @@ Module._resolveFilename = function(request, parent, isMain, options) {
   const filename = Module._findPath(request, paths, isMain);
   if (!filename) {
     const requireStack = [];
-    for (var cursor = parent;
+    for (let cursor = parent;
       cursor;
       cursor = cursor.parent) {
       requireStack.push(cursor.filename || cursor.id);
@@ -794,7 +790,7 @@ Module._resolveFilename = function(request, parent, isMain, options) {
       message = message + '\nRequire stack:\n- ' + requireStack.join('\n- ');
     }
     // eslint-disable-next-line no-restricted-syntax
-    var err = new Error(message);
+    const err = new Error(message);
     err.code = 'MODULE_NOT_FOUND';
     err.requireStack = requireStack;
     throw err;
@@ -858,7 +854,7 @@ Module.prototype.require = function(id) {
 
 // Resolved path to process.argv[1] will be lazily placed here
 // (needed for setting breakpoint when called with --inspect-brk)
-var resolvedArgv;
+let resolvedArgv;
 let hasPausedEntry = false;
 
 // Run the file contents in the correct scope or sandbox. Expose
@@ -928,7 +924,7 @@ Module.prototype._compile = function(content, filename) {
     compiledWrapper = compiled.function;
   }
 
-  var inspectorWrapper = null;
+  let inspectorWrapper = null;
   if (getOptionValue('--inspect-brk') && process._eval == null) {
     if (!resolvedArgv) {
       // We enter the repl if we're not given a filename argument.
@@ -947,7 +943,7 @@ Module.prototype._compile = function(content, filename) {
   }
   const dirname = path.dirname(filename);
   const require = makeRequireFunction(this, redirects);
-  var result;
+  let result;
   const exports = this.exports;
   const thisValue = exports;
   const module = this;
@@ -1090,26 +1086,16 @@ function createRequire(filename) {
 Module.createRequire = createRequire;
 
 Module._initPaths = function() {
-  var homeDir;
-  var nodePath;
-  if (isWindows) {
-    homeDir = process.env.USERPROFILE;
-    nodePath = process.env.NODE_PATH;
-  } else {
-    homeDir = safeGetenv('HOME');
-    nodePath = safeGetenv('NODE_PATH');
-  }
+  const homeDir = isWindows ? process.env.USERPROFILE : safeGetenv('HOME');
+  const nodePath = isWindows ? process.env.NODE_PATH : safeGetenv('NODE_PATH');
 
-  // $PREFIX/lib/node, where $PREFIX is the root of the Node.js installation.
-  var prefixDir;
   // process.execPath is $PREFIX/bin/node except on Windows where it is
-  // $PREFIX\node.exe.
-  if (isWindows) {
-    prefixDir = path.resolve(process.execPath, '..');
-  } else {
-    prefixDir = path.resolve(process.execPath, '..', '..');
-  }
-  var paths = [path.resolve(prefixDir, 'lib', 'node')];
+  // $PREFIX\node.exe where $PREFIX is the root of the Node.js installation.
+  const prefixDir = isWindows ?
+    path.resolve(process.execPath, '..') :
+    path.resolve(process.execPath, '..', '..');
+
+  let paths = [path.resolve(prefixDir, 'lib', 'node')];
 
   if (homeDir) {
     paths.unshift(path.resolve(homeDir, '.node_libraries'));
@@ -1143,7 +1129,7 @@ Module._preloadModules = function(requests) {
       throw e;
     }
   }
-  for (var n = 0; n < requests.length; n++)
+  for (let n = 0; n < requests.length; n++)
     parent.require(requests[n]);
 };