fixup! repl: refactor to avoid unsafe array iteration

RaisinTen · Dec 28, 2020 · Dec 28, 2020 · Dec 29, 2020 · Dec 29, 2020 · Jan 13, 2021
commit 7e0103de9c2b4f6a743cad8b7511e11771158c93
diff --git a/lib/internal/repl/utils.js b/lib/internal/repl/utils.js
@@ -245,7 +245,7 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       }
 
       // Result and the text that was completed.
-      const [rawCompletions, completeOn] = data;
+      const { 0: rawCompletions, 1: completeOn } = data;
 
       if (!rawCompletions || rawCompletions.length === 0) {
         return;

diff --git a/lib/internal/util/debuglog.js b/lib/internal/util/debuglog.js
@@ -54,7 +54,7 @@ function debuglogImpl(enabled, set) {
       emitWarningIfNeeded(set);
       debugImpls[set] = function debug(...args) {
         const colors = process.stderr.hasColors && process.stderr.hasColors();
-        const msg = formatWithOptions({ colors }, ...args);
+        const msg = formatWithOptions({ colors }, args);
         const coloredPID = inspect(pid, { colors });
         process.stderr.write(format('%s %s: %s\n', set, coloredPID, msg));
       };

diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
@@ -1868,18 +1868,18 @@ function tryStringify(arg) {
 }
 
 function format(...args) {
-  return formatWithOptionsInternal(undefined, ...args);
+  return formatWithOptionsInternal(undefined, args);
 }
 
-function formatWithOptions(inspectOptions, ...args) {
+function formatWithOptions(inspectOptions, args) {
   if (typeof inspectOptions !== 'object' || inspectOptions === null) {
     throw new ERR_INVALID_ARG_TYPE(
       'inspectOptions', 'object', inspectOptions);
   }
-  return formatWithOptionsInternal(inspectOptions, ...args);
+  return formatWithOptionsInternal(inspectOptions, args);
 }
 
-function formatWithOptionsInternal(inspectOptions, ...args) {
+function formatWithOptionsInternal(inspectOptions, args) {
   const first = args[0];
   let a = 0;
   let str = '';

diff --git a/lib/repl.js b/lib/repl.js
@@ -1268,7 +1268,7 @@ function complete(line, callback) {
     }
   } else if (RegExpPrototypeTest(fsAutoCompleteRE, line) &&
              this.allowBlockingCompletions) {
-    [completionGroups, completeOn] = completeFSFunctions(line);
+    ({ 0: completionGroups, 1: completeOn } = completeFSFunctions(line));
   // Handle variable member lookup.
   // We support simple chained expressions like the following (no function
   // calls, etc.). That is for simplicity and also because we *eval* that
@@ -1281,7 +1281,7 @@ function complete(line, callback) {
   //   foo.<|>        # completions for 'foo' with filter ''
   } else if (line.length === 0 ||
              RegExpPrototypeTest(/\w|\.|\$/, line[line.length - 1])) {
-    const [match] = RegExpPrototypeExec(simpleExpressionRE, line) || [''];
+    const { 0: match } = RegExpPrototypeExec(simpleExpressionRE, line) || [''];
     if (line.length !== 0 && !match) {
       completionGroupsLoaded();
       return;
@@ -1388,7 +1388,8 @@ function complete(line, callback) {
 
     const completions = [];
     // Unique completions across all groups.
-    const uniqueSet = new SafeSet(['']);
+    const uniqueSet = new SafeSet();
+    uniqueSet.add('');
     // Completion group 0 is the "closest" (least far up the inheritance
     // chain) so we put its completions last: to be closest in the REPL.
     ArrayPrototypeForEach(completionGroups, (group) => {

diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
@@ -504,7 +504,56 @@ const tests = [
       prompt,
     ],
     clean: true
-  }
+  },
+  {
+    env: { NODE_REPL_HISTORY: defaultHistoryPath },
+    test: (function*() {
+      // Deleting Array iterator should not break history feature.
+      //
+      // Using a generator function instead of an object to allow the test to
+      // keep iterating even when Array.prototype[Symbol.iterator] has been
+      // deleted.
+      yield 'const ArrayIteratorPrototype =';
+      yield '  Object.getPrototypeOf(Array.prototype[Symbol.iterator]());';
+      yield ENTER;
+      yield 'const {next} = ArrayIteratorPrototype;';
+      yield ENTER;
+      yield 'const realArrayIterator = Array.prototype[Symbol.iterator];';
+      yield ENTER;
+      yield 'delete Array.prototype[Symbol.iterator];';
+      yield ENTER;
+      yield 'delete ArrayIteratorPrototype.next;';
+      yield ENTER;
+      yield UP;
+      yield UP;
+      yield DOWN;
+      yield DOWN;
+      yield 'fu';
+      yield 'n';
+      yield RIGHT;
+      yield BACKSPACE;
+      yield LEFT;
+      yield LEFT;
+      yield 'A';
+      yield BACKSPACE;
+      yield GO_TO_END;
+      yield BACKSPACE;
+      yield WORD_LEFT;
+      yield WORD_RIGHT;
+      yield ESCAPE;
+      yield ENTER;
+      yield 'Array.proto';
+      yield RIGHT;
+      yield '.pu';
+      yield ENTER;
+      yield 'ArrayIteratorPrototype.next = next;';
+      yield ENTER;
+      yield 'Array.prototype[Symbol.iterator] = realArrayIterator;';
+      yield ENTER;
+    })(),
+    expected: [],
+    clean: false
+  },
 ];
 const numtests = tests.length;