josdejong/mathjs

Expression rationalization gets stuck or takes too long (it worked in V9.5.1)

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#3,351 opened on Jan 16, 2025

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 (5 comments) (0 reactions) (0 assignees)JavaScript (13,832 stars) (1,298 forks)batch import
bughelp wanted

Description

Describe the bug Recently, I updated Math.js from version 9.5.1 to the latest version, and an expression rationalization that worked before doesn't work anymore. (see To Reproduce)

To Reproduce

import * as mathjs from 'mathjs';

const aa = mathjs.parse("6285.67^5/(s+6285.67)^5");
const bb = mathjs.rationalize(aa, {}, false); // It gets stuck here

console.log(bb.toString());

Contributor guide

Tech stack
javascript
Domain
performance
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.
active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
mathjs library usageexpression parsing
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate rationalize function in mathjs/src/expression/function/rationalize.js. Compare behavior between versions 9.5.1 and current. Look for changes in simplify or rationalize logic that could cause infinite loop or excessive computation. Examine the parse result for the given expression to see if any recent changes to expression tree processing lead to a hang.