repl: add isValidParentheses check before wrap input

Author: meixg

lib/internal/repl/utils.js

@@ -72,7 +72,7 @@ function isRecoverableError(e, code) {
   // here as the point is to test for potentially valid but incomplete
   // expressions.
   if (RegExpPrototypeExec(/^\s*\{/, code) !== null &&
-    isRecoverableError(e, `(${code}`))
+      isRecoverableError(e, `(${code}`))
     return true;
 
   let recoverable = false;
@@ -115,10 +115,10 @@ function isRecoverableError(e, code) {
 
               case 'Unterminated string constant': {
                 const token = StringPrototypeSlice(this.input,
-                  this.lastTokStart, this.pos);
+                                                   this.lastTokStart, this.pos);
                 // See https://www.ecma-international.org/ecma-262/#sec-line-terminators
                 if (RegExpPrototypeExec(/\\(?:\r\n?|\n|\u2028|\u2029)$/,
-                  token) !== null) {
+                                        token) !== null) {
                   recoverable = true;
                 }
               }
@@ -146,7 +146,7 @@ function isRecoverableError(e, code) {
 function setupPreview(repl, contextSymbol, bufferSymbol, active) {
   // Simple terminals can't handle previews.
   if (process.env.TERM === 'dumb' || !active) {
-    return { showPreview() { }, clearPreview() { } };
+    return { showPreview() {}, clearPreview() {} };
   }
 
   let inputPreview = null;
@@ -171,7 +171,7 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
   function isCursorAtInputEnd() {
     const { cursorPos, displayPos } = getPreviewPos();
     return cursorPos.rows === displayPos.rows &&
-      cursorPos.cols === displayPos.cols;
+           cursorPos.cols === displayPos.cols;
   }
 
   const clearPreview = (key) => {
@@ -212,9 +212,9 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
             escaped = repl.line;
           }
         } else if ((key.name === 'return' || key.name === 'enter') &&
-          !key.meta &&
-          escaped !== repl.line &&
-          isCursorAtInputEnd()) {
+                   !key.meta &&
+                   escaped !== repl.line &&
+                   isCursorAtInputEnd()) {
           repl._insertString(completionPreview);
         }
       }
@@ -289,22 +289,19 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
   function isInStrictMode(repl) {
     return repl.replMode === REPL_MODE_STRICT || ArrayPrototypeIncludes(
       ArrayPrototypeMap(process.execArgv,
-        (e) => StringPrototypeReplaceAll(
-          StringPrototypeToLowerCase(e),
-          '_',
-          '-',
-        )),
+                        (e) => StringPrototypeReplaceAll(
+                          StringPrototypeToLowerCase(e),
+                          '_',
+                          '-',
+                        )),
       '--use-strict');
   }
 
   // This returns a code preview for arbitrary input code.
   function getInputPreview(input, callback) {
     // For similar reasons as `defaultEval`, wrap expressions starting with a
     // curly brace with parenthesis.
-    if (StringPrototypeStartsWith(input, '{') &&
-      !StringPrototypeEndsWith(input, ';') &&
-      isValidSyntax(input) &&
-      !wrapped) {
+    if (!wrapped && input[0] === '{' && input[input.length - 1] !== ';' && isValidSyntax(input)) {
       input = `(${input})`;
       wrapped = true;
     }
@@ -322,16 +319,16 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
         const { result } = preview;
         if (result.value !== undefined) {
           callback(null, inspect(result.value, previewOptions));
-          // Ignore EvalErrors, SyntaxErrors and ReferenceErrors. It is not clear
-          // where they came from and if they are recoverable or not. Other errors
-          // may be inspected.
+        // Ignore EvalErrors, SyntaxErrors and ReferenceErrors. It is not clear
+        // where they came from and if they are recoverable or not. Other errors
+        // may be inspected.
         } else if (preview.exceptionDetails &&
-          (result.className === 'EvalError' ||
-            result.className === 'SyntaxError' ||
-            // Report ReferenceError in case the strict mode is active
-            // for input that has no completions.
-            (result.className === 'ReferenceError' &&
-              (hasCompletions || !isInStrictMode(repl))))) {
+                   (result.className === 'EvalError' ||
+                    result.className === 'SyntaxError' ||
+                    // Report ReferenceError in case the strict mode is active
+                    // for input that has no completions.
+                    (result.className === 'ReferenceError' &&
+                     (hasCompletions || !isInStrictMode(repl))))) {
           callback(null, null);
         } else if (result.objectId) {
           // The writer options might change and have influence on the inspect
@@ -371,9 +368,9 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
   const showPreview = (showCompletion = true) => {
     // Prevent duplicated previews after a refresh or in a multiline command.
     if (inputPreview !== null ||
-      repl[kIsMultiline] ||
-      !repl.isCompletionEnabled ||
-      !process.features.inspector) {
+        repl[kIsMultiline] ||
+        !repl.isCompletionEnabled ||
+        !process.features.inspector) {
       return;
     }
 
@@ -416,7 +413,7 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       // Do not preview `undefined` if colors are deactivated or explicitly
       // requested.
       if (inspected === 'undefined' &&
-        (!repl.useColors || repl.ignoreUndefined)) {
+          (!repl.useColors || repl.ignoreUndefined)) {
         return;
       }
 
@@ -430,7 +427,7 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
       // Support unicode characters of width other than one by checking the
       // actual width.
       if (inspected.length * 2 >= maxColumns &&
-        getStringWidth(inspected) > maxColumns) {
+          getStringWidth(inspected) > maxColumns) {
         maxColumns -= 4 + (repl.useColors ? 0 : 3);
         let res = '';
         for (const char of new SafeStringIterator(inspected)) {
@@ -469,8 +466,8 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
     let previewLine = line;
 
     if (completionPreview !== null &&
-      isCursorAtInputEnd() &&
-      escaped !== repl.line) {
+        isCursorAtInputEnd() &&
+        escaped !== repl.line) {
       previewLine += completionPreview;
     }
 
@@ -504,8 +501,8 @@ function setupPreview(repl, contextSymbol, bufferSymbol, active) {
     const currentCursor = repl.cursor;
     originalMoveCursor(dx);
     if (currentCursor + dx > repl.line.length &&
-      typeof repl.completer === 'function' &&
-      insertCompletionPreview) {
+        typeof repl.completer === 'function' &&
+        insertCompletionPreview) {
       const insertPreview = true;
       showCompletionPreview(repl.line, insertPreview);
     }
@@ -600,7 +597,7 @@ function setupReverseSearch(repl) {
       // Match not found.
       if (cursor === -1) {
         goToNextHistoryIndex();
-        // Match found.
+      // Match found.
       } else {
         if (repl.useColors) {
           const start = StringPrototypeSlice(entry, 0, cursor);
@@ -613,7 +610,7 @@ function setupReverseSearch(repl) {
         // Explicitly go to the next history item in case no further matches are
         // possible with the current entry.
         if ((dir === 'r' && cursor === 0) ||
-          (dir === 's' && entry.length === cursor + input.length)) {
+            (dir === 's' && entry.length === cursor + input.length)) {
           goToNextHistoryIndex();
         }
         return;
@@ -726,7 +723,7 @@ function setupReverseSearch(repl) {
     } else if (key.ctrl && checkAndSetDirectionKey(key.name)) {
       search();
     } else if (key.name === 'backspace' ||
-      (key.ctrl && (key.name === 'h' || key.name === 'w'))) {
+        (key.ctrl && (key.name === 'h' || key.name === 'w'))) {
       reset(StringPrototypeSlice(input, 0, input.length - 1));
       search();
       // Special handle <ctrl> + c and escape. Those should only cancel the
@@ -738,11 +735,11 @@ function setupReverseSearch(repl) {
       // End search in case either enter is pressed or if any non-reverse-search
       // key (combination) is pressed.
     } else if (key.ctrl ||
-      key.meta ||
-      key.name === 'return' ||
-      key.name === 'enter' ||
-      typeof string !== 'string' ||
-      string === '') {
+               key.meta ||
+               key.name === 'return' ||
+               key.name === 'enter' ||
+               typeof string !== 'string' ||
+               string === '') {
       reset();
       repl[kSubstringSearch] = '';
     } else {
@@ -789,52 +786,15 @@ function isValidSyntax(input) {
 function isObjectLiteral(code) {
   return RegExpPrototypeExec(startsWithBraceRegExp, code) !== null &&
     RegExpPrototypeExec(endsWithSemicolonRegExp, code) === null;
-  function isValidSyntax(input) {
-    const Parser = require('internal/deps/acorn/acorn/dist/acorn').Parser;
-    try {
-      Parser.parse(input, { ecmaVersion: 'latest' });
-      return true;
-    } catch {
-      return false;
-    }
-  }
-
-  function isValidParentheses(input) {
-    const stack = [];
-    const pairs = {
-      '(': ')',
-      '[': ']',
-      '{': '}',
-    };
-
-    for (let i = 0; i < input.length; i++) {
-      const char = input[i];
-
-      if (pairs[char]) {
-        stack.push(char);
-      } else if (char === ')' || char === ']' || char === '}') {
-        if (pairs[stack.pop()] !== char) {
-          return false;
-        }
-      }
-      function isValidSyntax(input) {
-        const Parser = require('internal/deps/acorn/acorn/dist/acorn').Parser;
-        try {
-          let result = Parser.parse(input, { ecmaVersion: 'latest' });
-          return true;
-        } catch (e) {
-          return false;
-        }
-      }
+}
 
-      module.exports = {
-        REPL_MODE_SLOPPY: Symbol('repl-sloppy'),
-        REPL_MODE_STRICT,
-        isRecoverableError,
-        kStandaloneREPL: Symbol('kStandaloneREPL'),
-        setupPreview,
-        setupReverseSearch,
-        isObjectLiteral,
-        isValidParentheses,
-        isValidSyntax,
-      };
+module.exports = {
+  REPL_MODE_SLOPPY: Symbol('repl-sloppy'),
+  REPL_MODE_STRICT,
+  isRecoverableError,
+  kStandaloneREPL: Symbol('kStandaloneREPL'),
+  setupPreview,
+  setupReverseSearch,
+  isObjectLiteral,
+  isValidSyntax,
+};