import-js/eslint-plugin-import

[BUG] ESLint crashes with `import/no-unused-modules`: Cannot read property 'get' of undefined

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#1,716 opened on Apr 2, 2020

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bughelp wanted

Description

Eslint-plugin-import crashes running eslint with Cannot read property 'get' of undefined error.

The error is in lib/rules/no-unused-module.js on line 262:

exportAll.forEach((value, key) => { value.forEach(val => { **const currentExports = exportList.get(val);** const currentExport = currentExports.get(EXPORT_ALL_DECLARATION); currentExport.whereUsed.add(key); }); }); However, if I add condition:

if (currentExports) { const currentExport = currentExports.get(EXPORT_ALL_DECLARATION); currentExport.whereUsed.add(key); } the lint works and I can see all the lint errors .

For now, I disabled the rule in .eslintrc.js file, but would it be possible to create a fix for it, or can I do it as well?

Version: "eslint-plugin-import": "^2.20.0"

Contributor guide

Tech stack
javascriptnodejs
Domain
backenddeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
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.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Basic JavaScriptFamiliarity with ESLint plugin rules
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
85
Research direction
The bug occurs in lib/rules/no unused module.js at line 262 where exportList.get(val) can return undefined. The fix is to add a null check before accessing currentExports. The issue already provides the exact code change. Look at the file to understand the context and ensure the fix doesn't break other cases.