gchq/CyberChef

bug(Swap Endianness): an uncaught TypeError "u.push is not a function"

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#2,495 opened on Jun 4, 2026

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 (1 comment) (0 reactions) (0 assignees)JavaScript (3,944 forks)batch import
buggood first issuehelp wanted

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Description

To reproduce that use a direct link https://gchq.github.io/CyberChef/#recipe=Swap_endianness('',2,true)&input=aGVsbG8&oenc=65001&oeol=VT

as you can see an uncaught type error appear like

Swap endianness - TypeError in blob:https://gchq.github.io/ca665e42-4811-40fc-9d6a-a868c6bd8271 on line 2.<br><br>Message: u.push is not a function

the issue simple the first parameter not validated is empty or not

Contributor guide

Research direction
Investigate the Swap endianness operation source code to add input validation for the first parameter when it is empty or undefined.
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.
1
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
None
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
90