Cannot build with Parcel: Unterminated regular expression

Description

$ PRODUCT_TYPE=webapp parcel entry/src/index.html --open
Server running at http://localhost:1234 
⚠️  Could not load existing sourcemap of "../../node_modules/react-spreadsheet-grid/lib/bundle.js".
🚨  /node_modules/react-spreadsheet-grid/lib/bundle.js:520:83: Unterminated regular expression (520:83)
  518 |         if (sourceMap) {
  519 |                 // http://stackoverflow.com/a/26603875
> 520 |                 css += "\n + btoa(unescape(encodeURIComponent(JSON.stringify(sourceMap)))) + " */";
      |                                                                                                 ^
  521 |         }
  522 | 
  523 |         var blob = new Blob([css], { type: "text/css" });

Contributor guide

Tech stack

javascriptreact

Domain

frontend

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.

1-3 hours

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

mostly clear

Prerequisites

JavaScriptregexParcel bundler basics

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

40

Research direction

Investigate the unterminated regular expression error at line 520 of the react spreadsheet grid bundle file (node modules/react spreadsheet grid/lib/bundle.js). The issue is caused by a broken regex in a line that adds sourcemap comment. Consider fixing the regex by properly escaping the expression or updating the dependency to a newer version. If the fix is simple, open a PR to patch the library or suggest a workaround like using a different bundler version.