repl: add missing variable declaration

* Adds `let` to a variable declaration in a for loop
  that wasn't using anything.

* Declare the for initial expression in the for loop.

* Remove hoisted variables for loops.

PR-URL: #29535
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

lib/repl.js

@@ -1089,7 +1089,7 @@ function complete(line, callback) {
   var completions;
   // List of completion lists, one for each inheritance "level"
   var completionGroups = [];
-  var completeOn, i, group, c;
+  var completeOn, group, c;
 
   // REPL commands (e.g. ".break").
   var filter;
@@ -1112,7 +1112,7 @@ function complete(line, callback) {
     completeOn = match[1];
     var subdir = match[2] || '';
     filter = match[1];
-    var dir, files, f, name, base, ext, abs, subfiles, s, isDirectory;
+    var dir, files, name, base, ext, abs, subfiles, isDirectory;
     group = [];
     let paths = [];
 
@@ -1126,14 +1126,14 @@ function complete(line, callback) {
       paths = module.paths.concat(CJSModule.globalPaths);
     }
 
-    for (i = 0; i < paths.length; i++) {
+    for (let i = 0; i < paths.length; i++) {
       dir = path.resolve(paths[i], subdir);
       try {
         files = fs.readdirSync(dir);
       } catch {
         continue;
       }
-      for (f = 0; f < files.length; f++) {
+      for (let f = 0; f < files.length; f++) {
         name = files[f];
         ext = path.extname(name);
         base = name.slice(0, -ext.length);
@@ -1154,7 +1154,7 @@ function complete(line, callback) {
           } catch {
             continue;
           }
-          for (s = 0; s < subfiles.length; s++) {
+          for (let s = 0; s < subfiles.length; s++) {
             if (indexRe.test(subfiles[s])) {
               group.push(subdir + name);
             }
@@ -1291,7 +1291,7 @@ function complete(line, callback) {
           }
 
           if (memberGroups.length) {
-            for (i = 0; i < memberGroups.length; i++) {
+            for (let i = 0; i < memberGroups.length; i++) {
               completionGroups.push(
                 memberGroups[i].map((member) => `${expr}.${member}`));
             }
@@ -1316,7 +1316,7 @@ function complete(line, callback) {
     // Filter, sort (within each group), uniq and merge the completion groups.
     if (completionGroups.length && filter) {
       var newCompletionGroups = [];
-      for (i = 0; i < completionGroups.length; i++) {
+      for (let i = 0; i < completionGroups.length; i++) {
         group = completionGroups[i]
           .filter((elem) => elem.indexOf(filter) === 0);
         if (group.length) {
@@ -1332,7 +1332,7 @@ function complete(line, callback) {
       // Completion group 0 is the "closest"
       // (least far up the inheritance chain)
       // so we put its completions last: to be closest in the REPL.
-      for (i = 0; i < completionGroups.length; i++) {
+      for (let i = 0; i < completionGroups.length; i++) {
         group = completionGroups[i];
         group.sort();
         for (var j = group.length - 1; j >= 0; j--) {