gchq/CyberChef

Bug report: 'JSON beautify' operation losing numeric precision

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#415 opened on Nov 20, 2018

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 (1 comment) (0 reactions) (0 assignees)JavaScript (34,843 stars) (3,944 forks)batch import
bughelp wanted

Description

Summary

When running the 'JSON beautify' operation, numeric precision is lost for large numbers.

Example

https://gchq.github.io/CyberChef/#recipe=JSON_Beautify('%5C%5Ct')&input=eyAiYSI6IDEyMzQ1Njc4OTAxMjM0NTY3ODkgfQ

Input:

{ "a": 1234567890123456789 }

Erroneous output:

{
	"a": 1234567890123456800
}

Contributor guide

Tech stack
javascript
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.
clear
Prerequisites
JavaScript number precisionJSON parsing basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Examine the JSON beautify operation in CyberChef's source code (likely under src/core/operations/). The bug is due to JavaScript's Number type losing precision for integers beyond 2^53. Look for where JSON parsing occurs and consider using a custom parser or BigInt to preserve large numbers. Check the issue comments for any prior discussion or attempted fixes.