parcel-bundler/parcel

Build failed. unknown: Error parsing package.json: Unexpected token  in JSON at position 0

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#8378 opened on Aug 8, 2022

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 (4 comments) (0 reactions) (0 assignees)JavaScript (44,030 stars) (2,274 forks)batch import
:bug: Bug:heavy_check_mark: Confirmed Bug:pray: Help WantedGood First Issue

Description

🐛 bug report

🚨 Build failed.

unknown: Error parsing package.json: Unexpected token  in JSON at position 0

this bug for exist 77u/ char for utf8 file. when save package.json with utf8 encoded added 77u/ char in first of content file. parcel json parser need { char for first. Screenshot 2022-08-08 175010

visual studio and many editor always sign utf8 file with 77u/

Software Version(s)
Parcel 2.7.0
Node 18.7.0
npm/Yarn 8.15.0
Operating System windows 11

Contributor guide

Tech stack
javascriptnodejs
Domain
build systemdeveloper experience
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.
clear
Prerequisites
understanding of JSON BOMbasic Node.js file operations
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
The issue is caused by a UTF 8 BOM (byte order mark) at the start of package.json, which is not handled by Parcel's JSON parser. The fix likely involves stripping the BOM (0xEFBBBF) before parsing. Look at how Parcel reads package.json, probably in src/Config.js or similar files that use JSON.parse. Consider using a utility to remove BOM from file content before parsing, or use a more robust JSON parser. Ensure the fix is applied to all JSON file reads. No linked PRs or assignees, so the issue is open for contribution.