debugger: fix behavior of plain object exec in debugger repl

Co-authored-by: Xuguang Mei <meixuguang@gmail.com> PR-URL: #57498 Fixes: #46808 Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: 2 people

lib/internal/debugger/inspect_repl.js

@@ -56,6 +56,7 @@ const { fileURLToPath } = require('internal/url');
 
 const { customInspectSymbol, SideEffectFreeRegExpPrototypeSymbolReplace } = require('internal/util');
 const { inspect: utilInspect } = require('internal/util/inspect');
+const { isObjectLiteral } = require('internal/repl/utils');
 const debuglog = require('internal/util/debuglog').debuglog('inspect');
 
 const SHORTCUTS = {
@@ -573,8 +574,15 @@ function createRepl(inspector) {
  if (input === '\n') return lastCommand;
  // Add parentheses: exec process.title => exec("process.title");
  const match = RegExpPrototypeExec(/^\s*(?:exec|p)\s+([^\n]*)/, input);
+ input = match ? match[1] : input;
+
+ if (isObjectLiteral(input)) {
+ // Add parentheses to make sure `input` is parsed as an expression
+ input = `(${StringPrototypeTrim(input)})\n`;
+ }
+
  if (match) {
- lastCommand = `exec(${JSONStringify(match[1])})`;
+ lastCommand = `exec(${JSONStringify(input)})`;
  } else {
  lastCommand = input;
  }

lib/internal/repl/utils.js

@@ -739,11 +739,28 @@ function setupReverseSearch(repl) {
  return { reverseSearch };
 }
 
+const startsWithBraceRegExp = /^\s*{/;
+const endsWithSemicolonRegExp = /;\s*$/;
+
+/**
+ * Checks if some provided code represents an object literal.
+ * This is helpful to prevent confusing repl code evaluations where
+ * strings such as `{ a : 1 }` would get interpreted as block statements
+ * rather than object literals.
+ * @param {string} code the code to check
+ * @returns {boolean} true if the code represents an object literal, false otherwise
+ */
+function isObjectLiteral(code) {
+ return RegExpPrototypeExec(startsWithBraceRegExp, code) !== null &&
+ RegExpPrototypeExec(endsWithSemicolonRegExp, code) === null;
+}
+
 module.exports = {
  REPL_MODE_SLOPPY: Symbol('repl-sloppy'),
  REPL_MODE_STRICT,
  isRecoverableError,
  kStandaloneREPL: Symbol('kStandaloneREPL'),
  setupPreview,
  setupReverseSearch,
+ isObjectLiteral,
 };

lib/repl.js

@@ -171,6 +171,7 @@ const {
  kStandaloneREPL,
  setupPreview,
  setupReverseSearch,
+ isObjectLiteral,
 } = require('internal/repl/utils');
 const {
  constants: {
@@ -441,13 +442,8 @@ function REPLServer(prompt,
  let awaitPromise = false;
  const input = code;
 
- // It's confusing for `{ a : 1 }` to be interpreted as a block
- // statement rather than an object literal. So, we first try
- // to wrap it in parentheses, so that it will be interpreted as
- // an expression. Note that if the above condition changes,
- // lib/internal/repl/utils.js needs to be changed to match.
- if (RegExpPrototypeExec(/^\s*{/, code) !== null &&
- RegExpPrototypeExec(/;\s*$/, code) === null) {
+ if (isObjectLiteral(code)) {
+ // Add parentheses to make sure `code` is parsed as an expression
  code = `(${StringPrototypeTrim(code)})\n`;
  wrappedCmd = true;
  }

test/parallel/test-debugger-exec.js

@@ -60,6 +60,11 @@ async function waitInitialBreak() {
  /\[ 'undefined', 'function' \]/,
  'non-paused exec can see global but not module-scope values'
  );
+
+ // Ref: https://github.com/nodejs/node/issues/46808
+ await cli.waitForPrompt();
+ await cli.command('exec { a: 1 }');
+ assert.match(cli.output, /\{ a: 1 \}/);
  } finally {
  await cli.quit();
  }