no-fn-reference-in-iterator: Ignore locally declared functions?

Description

const fn = item => {
  // do stuff with iterator items
};

iter1.forEach(fn);
iter2.forEach(fn);
iter3.forEach(fn);

const mapper = require('unicorn-mapper');

function doStuff(iter, fn) {
  iter.forEach(fn); // error on `fn` provided by argument
}

[2, 3, 4].forEach(mapper); // error as `mapper` is from a `require`

Contributor guide

Tech stack

javascriptnodejs

Domain

developer experiencetooling

Issue type

feature

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

ESLint plugin developmentAST traversalJavaScript

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

60

Research direction

Examine the current implementation of the `no fn reference in iterator` rule in the repo (likely in `rules/no fn reference in iterator.js`). The rule currently flags all function references passed to iterators. Modify the AST visitor to check whether the function reference is a locally declared variable (e.g., a `const` or `let` declaration in the same scope) versus a parameter or imported function. Use scope analysis to distinguish. Add test cases covering both accepted and rejected patterns as provided in the issue.