nodejs/node

repl: no RegExp side effects

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#18,931 opened on Feb 22, 2018

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 (4 comments) (0 reactions) (1 assignee)JavaScript (117,218 stars) (35,535 forks)batch import
help wantedrepl

Description

$ ./out/Release/node 
> RegExp.$_
'\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000'

Caused by the repl trying to fix up the side effects to RegExp.$1 toRegExp.$9. :-)

Contributor guide

Tech stack
javascriptnodejs
Domain
cli
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.
1-2 days
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
JavaScriptNode.js internalsRegExp static properties
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Review the Node.js REPL source code, particularly the function that handles evaluation and cleanup of RegExp static properties (RegExp.$ and $1 $9). The bug is caused by the REPL attempting to preserve side effects across evaluations. Look in lib/repl.js for where these properties are set or cleared after each command. Check if there is a missing reset step. Also, review any existing work by the assignee on a branch if available. The fix likely involves ensuring these properties are not polluted between REPL evaluations.