beautifier/js-beautify

Option unescape_strings can produce invalid string literals making JS invalid/uninterpretable

Open

#2141 opened on Mar 17, 2023

View on GitHub
 (9 comments) (0 reactions) (0 assignees)JavaScript (8,342 stars) (1,460 forks)batch import
good first issuelanguage: javascripttype: bug

Description

Description

Option unescape_strings can produce invalid string literals making JS invalid/uninterpretable

Input

The code looked like this before beautification:

        function () {
          i.exports = "\t\n\x0B\f\r   ᠎             　\u2028\u2029\ufeff"
        }()

Expected Output

The code should have looked like this after beautification: code that does not contain invalid string literals

Actual Output

The code actually looked like this after beautification:

        function () {
          i.exports = "\t\n\x0B\f\r   ᠎             　

"
        }()

Steps to Reproduce

Environment

OS: Firefox/Win10

Settings

{
        "unescape_strings": true,
}

Contributor guide

Tech stack
javascriptnodejs
Domain
tooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Basic JavaScriptUnderstanding of string escaping
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
80
Research direction
The bug is in the 'unescape strings' option of js beautify. Look at the code in lib/beautifier.js or src/js/beautifier.js to see how unescaping is implemented. The issue is that certain Unicode characters like line separators are being converted to actual newlines, breaking the string literal. Investigate the regex or string replacement logic that handles escaped sequences, and ensure that only intended escape sequences are unescaped without introducing invalid literals. Check the existing test files for string handling to understand expected behavior.